Easy-to-use rapid test for direct detection ofCampylobacter spp. in chicken feces
01 Dec 2009
Journal of Food Protection®, Volume 72, Number 12, pp. 2483-2488(6)
Wadl, M.; Pölzler, T.; Flekna, G.; Thompson, L.; Slaghuis, J.; Köfer, J.; Hein, I.; Wagner, M.
Human campylobacteriosis is the leading cause of acute bacterial gastroenteritis in developed countries. One important source of infection is poultry. Results from the Dutch Campylobacter Risk Management and Assessment project indicate that meat from broiler flocks shedding =7 log CFU Campylobacter per g of feces poses the greatest risk of transmitting campylobacteriosis. The objective of the study was to develop a simple and rapid test that would identify chicken flocks shedding high numbers ofCampylobacter. The simple and rapid lateral flow test may contribute significantly to the identification of chicken flocks shedding high numbers ofCampylobacter.

Risk assessment in shellfish-borne outbreaks of hepatitis A
01 Dec 2009
Applied and Environmental Microbiology, p. 7350-7355, Vol. 75, No. 23
Rosa M. Pintó, M. Isabel Costafreda, and Albert Bosch [edited][FSNet]
Researchers aimed to determine the relationship between the hepatitis A virus (HAV) numbers in imported frozen coquina clams involved in two hepatitis outbreaks, as well as the risk for human health. The researcher believe their work provides the first evidence of accurate HAV levels in shellfish involved in outbreaks that could be of use for risk assessment purposes.

Analyzing the power and error ofListeria monocytogenesgrowth challenge studies
30 Nov 2009
International Journal of Food Microbiology Volume 136, Issue 1 [edited][FSNet]
Domestic and international food safety policy developments have spurred interest in the design and interpretation of experimental growth challenge studies to determine whether ready-to-eat (RTE) foods are able to support growth ofListeria monocytogenes. Existing challenge study protocols and those under development differ markedly in terms of experimental design and the acceptance criteria under which a RTE food is determined not to supportL. monocytogenesgrowth. Consequently, the protocols differ substantially with respect to the probability of incorrectly determining that growth occurs and the statistical power to detect growth if it does occur. None of theL. monocytogenesgrowth challenge study designs currently being considered are likely to provide an F-test with a = 0.05 and power = 0.8 to detect a 1 log10 increase in mean concentration over the entire range of measurement uncertainty values for enumeration ofL. monocytogenesreported in food samples in a validation study of ISO Method 11290-2.

Diversity ofLeuconostoc gasicomitatumassociated with meat spoilage
30 Nov 2009
International Journal of Food Microbiology, Volume 136, Issue 1 [edited][FSNet]
Leuconostoc gasicomitatumisolates (n = 384) associated with spoilage of meat and vegetable-based foods were characterised by pulsed-field gel electrophoresis (PFGE) typing. Our aim was to evaluate the diversity and distribution of spoilage-associatedL. gasicomitatumisolates from meat products, and to determine whether the PFGE genotypes are specific to product, producer, or isolation year (1997-2007). PFGE typing differentiated the isolates into 68 genotypes, and revealed that none one of the 54 genotypes associated with meat products was recovered from vegetable-based foods. Generally, the meat-derived genotypes were not specific to meat animal species, and many genotypes included isolates from products of different types or processors, as well as isolates collected in different years. Furthermore, certain genotypes were repeatedly identified from products of the same processing plant suggesting that the processing environment may have an impact onL. gasicomitatumcontamination of meat products.

Effect of temperature on uptake and survival ofVibrio parahaemolyticusin oysters(Crassostrea plicatula)
30 Nov 2009
International Journal of Food Microbiology, Volume 136, Issue 1 [edited][FSNet]
Xiaosheng Shen, Youqiong Cai, Chengchu Liu, Wenwei Liu, Yunhua Hui and Yi-Cheng Su
This study investigated accumulation ofVibrio parahaemolyticusin Zhe oyster (Crassostrea plicatula) from culture water and effectiveness of frozen and chilled storage on reducingV. parahaemolyticusin oysters. Freshly harvested oysters were placed in artificial seawater containingV. parahaemolyticus(104 CFU/mL) at 16, 20, 26, and 32 °C for 96 h. Contaminated oysters were stored at chilled temperatures (0, 5, and 15 °C) and frozen at - 18 and - 30 °C and changes ofV. parahaemolyticuspopulations in oysters were determined using the most probable number (MPN) method. Accumulations ofV. parahaemolyticusinC. plicatulareached the peaks at 6.66 (32 °C), 5.72 (26 °C), 5.04 (20 °C), 4.72 (16 °C) log MPN/g after 32 h in contaminated artificial seawater. Holding contaminated Zhe oysters at 5 and 0 °C reducedV. parahaemolyticuspopulations in both shell stock and shucked oysters. Populations ofV. parahaemolyticusin shell stock and shucked oysters declined by 1.42 and 2.0 log MPN/g, respectively, after 96 h of storage at 5 ºC and by 2.11 and 2.38 log MPN/g, respectively, after 96 h of storage at 0 °C. However, populations ofV. parahaemolyticusincreased by 2.44 log MPN/g in shell stock oysters and by 1.64 log MPN/g in shucked oysters when stored at 15 °C for 60 h. Frozen storage was effective in inactivatingV. parahaemolyticus.

Fate of acid resistant and non-acid resistant shiga toxin-producingEscherichia colistrains in ruminant digestive contents in the absence and presence of probiotics
30 Nov 2009
Applied and Environmental Microbiology [edited][FSNet]
Frédérique Chaucheyras-Durand, Fahima Faqir, et al.
Healthy ruminants are the main reservoir of Shiga toxin-producingEscherichia coli(STEC). During their transit through the ruminant gastro-intestinal tract, STEC encounter a number of acidic environments. As all STEC strains are not equally resistant to acidic conditions, the purpose of this study was to investigate whether acid-resistance confers an ecological superiority to STEC strains in the ruminant digestive contents, and whether acid-resistance mechanisms are induced in the rumen compartment. Researchers found that acid-resistant STEC survived at higher rates during prolonged incubation in rumen fluid than acid-sensitive STEC, and resisted to the high acidic conditions of the abomasum fluid whereas acid-sensitive strains were killed. The results of this study indicate that the rumen compartment could be a relevant target for intervention strategies that would both limit STEC survival and avoid the induction of acid resistance mechanisms, in order to decrease viable STEC cells reaching the hindgut and thus STEC shedding and food contamination.

Evolution of new variants ofVibrio choleraeO1
30 Nov 2009
Trends in Microbiology [edited][FSNet]
Ashrafus Safa, G. Balakrish Nair and Richard Y.C. Kong
Vibrio choleraetypically contains a prophage that carries the genes encoding the cholera toxin, which is responsible for the major clinical symptoms of the disease. In recent years, new pathogenic variants ofV. choleraehave emerged and spread throughout many Asian and African countries. Here, the researchers describe recent advances in our understanding of the epidemiology and evolution of the atypical El Tor strains.

Effects of packaging type and storage temperature on the growth of foodborne pathogens on shredded Romaine lettuce26 Nov 2009
Food Microbiology [edited][FSNet]
M. Oliveira, J. Usall, et al.
Fresh produce can be a vehicle for the transmission of pathogens capable of causing human illnesses and some of them can grow on fresh-cut vegetables. The survival and growth ofEscherichia coliO157:H7,Salmonellaspp. andListeria monocytogenesinoculated onto shredded lettuce was determined under modified atmosphere packaging conditions, at various storage temperatures. We also monitored changes in pH and gas atmospheres within the packages and the growth of psychrotrophic and mesophilic microorganisms. After pathogen inoculation, shredded lettuce was packaged in films of different permeability and stored at 5 and 25 °C. After 10 days at 5°C populations ofE. coliO157:H7 andSalmonelladecreased approximately 1.00 log unit whileL. monocytogenesincreased about 1.00 log unit, in all package films. Moreover, the pathogens level increased between 2.44-4.19 log units after 3 days at 25°C. Psychrotrophic and mesophilic bacteria had similar growth at both temperatures with higher populations in air than in the other atmospheres. The composition of the storage atmosphere within the packaging of lettuce had no significant effect on the survival and growth of the pathogens used in this study at refrigeration temperatures. The results obtained can be considered as a warning indicator, which reinforces the necessity for corrective measures to avoid contamination of vegetables.

Updated Mycotoxins information statement

26 Nov 2009
IFST [edited][FSNet]
Mycotoxins occur widely in nature and are produced by filamentous fungi. Organisms producing them can develop in the foods at any stage in the food chain from farm to fork. They may be present in the food as a result of the organism growing and producing the toxin or they enter the food chain by a more indirect route, for example in milk from animals that have consumed contaminated feed.
Effective control requires a combination of good agricultural practice, carefully controlled storage conditions and surveillance at every stage from farm to fork. Developing economies are at particular risk of contamination as moist, warm climatic conditions favour mould growth, while adequate control and good storage may be difficult to achieve.
While over 300 mycotoxins have been identified, about 20 have been shown to occur naturally in foods and feeds at significant levels and frequency to be of a food safety concern. The majority of these toxins are produced by fungi of the genera, Aspergillus, Penicillium and Fusarium. The most commonly occurring mycotoxins include aflatoxins (B1, B2, G1, G2, M1), ochratoxin A, patulin, citrinin, sterigmatocystin and the fusarium toxins namely fumonisins (B1, B2 and B3), zearalenone, T-2 and HT-2 toxins, nivalenol and deoxynivalenol.
Direct contamination occurs when the food or feed becomes infected with a toxigenic fungus with subsequent toxin formation. Indirect contamination occurs when an ingredient of a process has previously become contaminated with toxigenic fungus and, while the fungus may be eliminated or destroyed during processing, the toxins will mostly remain in the final product. Most of the important mycotoxins are, in general, quite resistant to most forms of food and feed processing.
Mycotoxin contamination of food and feeds is a world-wide problem. The Food and Agriculture Organisation (FAO) estimated that 25% of the world’s food crops are significantly contaminated with mycotoxins. Currently, more than 100 countries have regulations regarding levels of mycotoxins in the food and feed industry. Direct economic losses resulting from mycotoxin-contaminated agricultural crops can be measured in reduced crop yields and lower quality, reduced animal performance and reproductive capabilities, and increased disease incidence. Globalisation of food trade with regard to mycotoxins may have contributed to two major issues in the developing world. First, stringent mycotoxin standards on exported food crops mean that these countries are likely to export their best-quality foods while keeping contaminated foods domestically, which inadvertently results in higher risk of mycotoxin exposure in those nations. Second, a large portion of even the best quality foods produced in the developing world for export is rejected for not meeting the stringent standards, resulting in millions of dollars in losses.
Foods in which mycotoxins have been detected in recent years include peanuts, dried figs, apples (patulin) and coffee beans. Ochratoxin in animal feed has led to nephrotoxicity in pigs consuming that feed.

Antimicrobial activity of decontamination treatments for poultry carcasses: A literature survey23 Nov 2009
Food Control [edited][FSNet]
The decontamination of poultry carcasses is gaining increased interest in Europe, especially because poultry is implicated as a risk factor in human campylobacteriosis. Researchers appraised the antibacterial activity of interventions applied on poultry carcasses. Physical interventions included water-based treatments, irradiation, ultrasound, air chilling, or freezing. Especially hot water, steam, electrolyzed water (EW), and irradiation effectively reduced the bacterial load. However, hot water or steam might exert an adverse impact on the carcass appearance. Chemical interventions primarily comprised organic acids, chlorine-based treatments, or phosphate-based treatments. Besides, some combination treatments further enhanced the reductions. However, organic matter often reduces the antimicrobial activity of chemicals. Furthermore, biological interventions (e.g. bacteriophages) constitute promising alternatives, but further investigations are required. Although the mentioned interventions reduced the bacterial loads on poultry carcasses to some extent, decontamination treatments always must be considered part of an integral food safety system.

Reducing oyster-associated bacteria levels using supercritical fluid CO2 as an agent of warm pasteurization
21 Nov 2009
International Journal of Food Microbiology [edited][FSNet]
Damaris A.F. Meujo, Dion Kevin, et al.
An innovative approach to Post-Harvest Processing (PHP) of oysters is introduced focusing on the effects of supercritical carbon dioxide (scCO2) on bacterial contaminants trapped in the digestive system of oysters. The authors report the effect of scCO2 on several bacterial isolates, including a referenced ATCC strain of a non pathogenicVibrio (V. fisherii) as well as several other bacterial isolates cultured from oyster’ tissues and found to share biochemical features common to pathogenicVibriostrains. A complete inactivation (minimum 7-log reduction) was achieved with these latter bacterial isolates. A 6-log reduction was observed withV. fisherii.

Effects of technological processes on the tenacity and inactivation of Norovirus GGII in experimentally contaminated foods
20 Nov 2009
American Society for Microbiology [edited][FSNet]
Sascha Mormann, Mareike Dabisch, and Barbara Becker
Contaminated food is a significant vehicle of human norovirus transmission. The present study determined the effect of physicochemical treatments on the tenacity of infective human norovirus genogroup II in selected foods. Artificially contaminated produce was subjected to a selection of processes used by the food industry for preservation and by the consumer for storage and preparation. Significant titer reductions were obtained with heat treatments usually applied by the consumer for food preparation (baking, cooking, roasting). Generally, processes for preservation and storage, such as cooling, freezing, acidification (pH 4.5) and moderate heat treatments (pasteurization) appear to be insufficient to inactivate norovirus within a food matrix or on the surface. Beside the persistence in processed food, this study provides comparable data about individual matrix-specific protective effects, recovery rates and inhibitory influences on the PCR reactions. The established workflow might be applied to other non-cultivable enteric RNA viruses which are connected to foodborne diseases. The obtained data of this project may also benefit the process optimization for norovirus inactivation in food by adjusting food processing technologies and promote the development of risk assessment systems in order to improve the consumer protection.

Efficacy of aqueous and alcohol-based quaternary ammonium sanitizers for reducingSalmonellain dusts generated in almond hulling and shelling facilities
Journal of Food Science [edited][FSNet]
Wen-Xian Du, Michelle D. Danyluk, and Linda J. Harris
Large volumes of fine particulate matter or "dust" (soil, hulls, and shells) generated when hulls and shells are removed from almond kernels complicate cleaning and sanitation procedures in the huller-sheller (HS) environment. This study evaluated the efficacy of 3 aqueous quaternary ammonium sanitizers (AQuats) and an isopropyl alcohol-based quaternary ammonium sanitizer (IPAQuat) for reducingSalmonellain dust collected from 2 HS facilities. At either 15 or 30 °C increases inSalmonellapopulations in the dust were not significantly different following addition of either water or AQuats. No significant differences were observed upon water or AQuat addition, either among the 3 AQuats tested, the concentration or volume of AQuat, or the initial level of Salmonella. When IPAQuat was added to dust inoculated at 1 to 7 log CFU/g, Salmonella levels were reduced to less than 1.3 log CFU/g after treatment and after incubation at 30 °C for 48 h. IPAQuat was an effective sanitizer compared to the AQuats, even in the presence of high levels of organic material. Recent large-scale outbreaks of salmonellosis with low-moisture foods have increased concerns regarding their safety. This research is focused on an evaluation of sanitation options for low-moisture foods, in particular almonds. The information should be applicable and useful to the nut industry and to other low-moisture foods.

Spinacia oleracea L. leaf stomata harboring Cryptosporidium parvum oocysts: A potential threat for food safety
20 Nov 2009
American Society for Microbiology [edited][FSNet]
Dumitru Macarisin, Gary Bauchan, and Ronald Fayer
Cryptosporidium parvumis a cosmopolitan microscopic protozoan parasite that causes severe diarrheal disease (cryptosporidiosis) in mammals, including humans and livestock. There is growing evidence ofCryptosporidiumpersistence in fresh produce that may result in foodborne infection, including sporadic cases as well as outbreaks. However, drinking or recreational waters are still considered the major source of cryptosporidiosis infection in humans, thereby prioritizing studies of parasite etiology in aquatic environments, while the mechanisms of transmission and parasite persistence on edible plants remain poorly understood. Using laser scanning confocal microscopy together with fluorescein-labeled monoclonal antibodiesCryptosporidium parvumoocysts were found to strongly adhere to spinach plants after contact with contaminated water, to infiltrate through the stomatal openings into spinach leaves, and to persist at the mesophyll level. These findings and the fact that this pathogenic parasite resists washing and disinfection raise concerns regarding food safety.

Survival ofcronobacterspecies in reconstituted herbal infant teas and their sensitivity to bovine lactoferrin

17 Nov 2009
Journal of Food Science, Volume 74 Issue 9, Pages M479 - M484 [edited][FSNet]
Anas A. Al-Nabulsi, Tareq M. Osaili, et al.
Cronobacteris a new genus containing 5 species previously known asEnterobacter sakazakii. The popularity of "natural" substances and alternative medicine has extended the use of natural antimicrobials and herbs to foods, and some herbs are claimed to relieve gastric disturbances in infants. The researchers in the present study investigated the antimicrobial activity of bovine lactoferrin (LF) andCronobactersurvival in commercial herbal infant teas (HITs) reconstituted with water at different temperatures. This study demonstrates that if present in reconstituted herbal infant tea,Cronobactercan grow and this may compromise the safety of these products. Therefore, addition of LF to reconstituted HIT may be a promising approach for the effective control of this organism.
Cronobacterspecies can be isolated from herbal teas, and these products are claimed to relieve gastric disturbances in infants. This study demonstrates thatCronobactercells present in reconstituted herbal infant teas (HITs) can grow if not held at acceptable temperatures. It was shown that reconstitution of these tea formulas with = 60 °C water reduced the potential risk fromCronobacter. Furthermore, use of lactoferrin (LF) may be a promising approach for effective control of these organisms in HIT held at nonrefrigeration temperatures (10 to 37 °C) for short periods.

Effect of organic acids and plant extracts onEscherichia coliO157:H7,Listeria monocytogenes, andSalmonellaTyphimurium in broth culture model and chicken meat systems
17 Nov 2009
Journal of Food Science, Volume 74 Issue 9, Pages M515 - M521 [edited][FSNet]
K.F. Over, N. Hettiarachchy, M.G. Johnson, and B. Davis
Foodborne illness due to consumption of products contaminated withSalmonellaTyphimurium (S.T.),Listeria monocytogenes(L.m.), andEscherichia coliO157:H7 (E.c.) results in many deaths and significant economic losses each year. In this study, acetic (AA), citric acid (CA), lactic acid (LA), malic acid (MA), and tartaric acid (TA) and grape seed (GS), green tea (GT), bitter melon seed (BMS), rasum, and fenugreek (FG) extracts were investigated as inhibitors against S.T., L.m., and E.c. in both broth-culture and meat systems. GT and GS showed considerable activity in broth-culture. All organic acids were effective in broth-culture at 75 mM after 24 h (P 5, >2, and 4-6 log CFU/g, respectively, although all organic acids showed some antibacterial activity at 75.0 and 150.0 mM. These findings demonstrate the effectiveness of organic acids and plant extracts in the control of S.T., L.m., and E.c. O157:H7.

Effect of salt, smoke compound, and temperature on the survival of Listeria monocytogenes in salmon during simulated smoking processes
17 Nov 2009
Journal of Food Science, Volume 74 Issue 9, Pages M522 - M529
Cheng-An Hwang, Shiowshuh Sheen, and Vijay K. Juneja [edited][FSNet]
The objectives of this study were to examine and develop a model to describe the survival ofListeria monocytogenesin salmon as affected by salt, smoke compound (phenol), and smoking process temperature. Cooked minced salmon containing selected levels of salt (0%, 2%, 4%, and 6%) and smoke compound (0, 5, 10, and 15 ppm phenol) were inoculated with a 6-strain mixture of L. monocytogenes to an inoculum level of 6.0 log10 CFU/g. The populations of L. monocytogenes in salmon during processing at 40, 45, 50, and 55 °C that simulated cold- and hot-smoking process temperatures were determined, and the effects of salt, phenol, and temperature on the survival of L. monocytogenes in salmon were analyzed and described with an exponential regression. At 40 °C, the populations of L. monocytogenes in salmon decreased slightly with inactivation rates of

Transmission dynamics of a multidrug-resistantSalmonellaTyphimurium outbreak in a dairy farm
17 Nov 2009
Foodborne Pathogens and Disease. doi:10.1089/fpd.2009.0411. [edited][FSNet]
Cristina Lanzas, Lorin D. Warnick, et al.
Cattle are recognized as an important source of foodborneSalmonellacausing human illness, particularly for antimicrobial-resistant strains. The transmission dynamics of multidrug-resistant (MDR)Salmonellaafter the onset of a clinical outbreak in a dairy farm has been rarely monitored. The early transmission of a pathogen influences the outbreak size and persistence of the pathogen at the farm level and, therefore, how long the herd represents a risk forSalmonellazoonotic transmission. The objective of this study was to describe the transmission dynamics of MDRSalmonellaTyphimurium after the onset of a clinical outbreak in a dairy herd. For that purpose, fecal shedding and serological response to MDRSalmonellawere monitored in a longitudinal study conducted in a dairy herd after a few cases of salmonellosis, and a stochastic transmission model was developed to predictSalmonellapersistence at the pen level. The outbreak was limited to five clinical cases, and only 18 animals out of 500 cows shedSalmonellain feces. The longest shedder was culture-positive forSalmonellafor at least 68 days. The isolates (n=27) were represented by four pulsed-field gel electrophoresis patterns; three patterns were similar. With one exception, isolates were resistant to nine or more antimicrobial drugs. Simulations of the transmission model indicated that approximately 50% of the outbreaks were likely to die out within 20 days after the first animal was infected. The simulation studies indicated that salmonellosis outbreaks with few clinical cases were likely due to the extinction of the pathogen in the premises in the early phase of the outbreaks. Small population size and group structure within the farm decrease the on-farm persistence of the pathogen.

Fetal, infant risk fromListeriahigher than previously reported
12 Nov 2009
Society for Risk Analysis [edited][FSNet]
A new study shows the risk for severe effects of exposure toListeria monocytogenesamong susceptible populations may occur at doses lower than suggested by previous studies. The risk of fetal or infant mortality among pregnant women who consume food containing one million cells of the food-borne pathogenListeria monocytogenesin soft cheeses and other foods is estimated at about 50 percent, suggesting five stillbirths potentially could occur when ten pregnant women are exposed to that amount. A previous risk assessment estimated more than 10 trillion cells would result in stillbirths to 50 percent of pregnant women exposed.
The study, “Risk of Fetal Mortality After Exposure toListeria MonocytogenesBased on Dose-Response Data from Pregnant Guinea Pigs and Primates,” was conducted by five researchers at the University of Georgia in Athens: Denita Williams, Ph.D and Mary Alice Smith, Ph.D, along with Jennifer Castleman, Chi-Ching Lee, and Beth Mote. Results are published in the November 2009 issue of Risk Analysis, which is published by the Society for Risk Analysis. The research was funded by the Center for Food Safety and Applied Nutrition of the U.S. Food and Drug Administration (FDA), the Food Safety Inspection Service of the U.S. Department of Agriculture (USDA), and the American Meat Institute Foundation.
The research team conducted a risk assessment focusing on consumption of contaminated Mexican-style soft cheese consumed by a woman in her third trimester of pregnancy. Using non-human primates and guinea pigs for their models, the researchers determined among a number of factors the level at which half of the primates or guinea pigs had stillbirths and then compared that data with estimates for human exposure to soft cheese. Ten of 33 pregnant primates exposed to a single dose ofListeriaexperienced stillbirths. Using these primate data, the new model predicted 50 percent stillborn births among pregnant women, at a dose similar to that estimated from an outbreak of Listeriosis among pregnant women. Exposures were measured using the FDA’s estimates for the number ofListeria-contaminated servings consumed by pregnant women. The dose ofListeriarequired for infection and onset of adverse effects was found to be more similar between humans, primates and guinea pigs than previous dosages used in government research that were adjusted from a mouse study.

World Health Organization:Tainted food surprisingly deadly in adults
11 Nov 2009
Reuters [edited][FSNet]
Millions of adults die every year from bugs and toxins in what they eat, according to new World Health Organisation data that shows food-borne diseases are far more deadly than the U.N. agency previously estimated.
The research faults unsafe food for 1.2 million deaths per year in people over the age of five in Southeast Asia and Africa -- three times more adult deaths than the Geneva-based WHO had thought occurred in the whole world.
Ailments linked to contaminated food and water have long been seen as a major threat to young children, who can dehydrate quickly. But the Danish veterinarian and microbiologist said the risks to older populations had been grossly underestimated.
Older children and the elderly are especially vulnerable to severe illness from major food- and water-borne diseases such assalmonella, listeria, E. coli, Hepatitis A and cholera.

09 Nov 2009
Food and Agriculture Organization of the United Nations (FAO) [edited][FSNet]
The paper aims to identify potential impacts of anticipated changes in climate on food safety and their control at all stages of the food chain. The purpose is to raise awareness of the issue and to facilitate international cooperation in better understanding the changing food safety situation and in developing and implementing strategies to address them.
While the paper takes a broad look at a number of food safety issues and considers possible implications of climate change – it does not provide exhaustive treatment of the topic. The food safety issues covered include: agents of food-borne disease with specific consideration of zoonotic diseases, mycotoxin contamination, biotoxins in fishery products and environmental contaminants with significance to the food chain. The paper also highlights the need for adequate attention to food safety in ensuring preparedness for effective management of emergency situations arising from extreme weather events. There is much uncertainty about possible food safety implications of climate change. The paper discusses some expected effects that are supported by data; it also considers other issues that are largely speculative.

Evidence-based semiquantitative methodology for prioritization of foodborne zoonoses
05 Nov 2009
Foodborne Pathogens and Disease. November 2009, 6(9): 1083-1096
Sabine Cardoen, Xavier Van Huffel, et al.
The objectives of the study were to prioritize an extended list of food- and water-borne zoonoses to allow food safety authorities to focus on the most relevant hazards in the food chain.
An evidence-based semiquantitative methodology was developed. Scores were given by 35 scientific experts in the field of animal and public health, food, and clinical microbiology and epidemiology to 51 zoonotic agents according to five criteria related to public health (severity and occurrence in humans), animal health (severity of disease coupled with economic consequences and occurrence in animals), and food (occurrence in food). The scoring procedure was standardized and evidence-based as experts were provided, for each zoonotic agent, a same set of up-to-date help information data related to the five criteria. Independently, the relative importance of the five criteria was weighted by seven food chain risk managers. The zoonotic agents were ranked based on overall weighted scores and were grouped in four statistically different levels of importance.
The following foodborne zoonotic pathogens were classified as “most important”:Salmonellaspp.,Campylobacterspp.,Listeria monocytogenes, and verocytotoxigenicEscherichia coli. A second group of “significant importance” includedToxoplasma gondii,the agent of bovine spongiform encephalopathy,Clostridium botulinum,Staphylococcus aureus,Cryptosporidium parvum,Mycobacterium bovis,Echinococcus granulosus, Streptococcus spp., Echinococcus multilocularis, Yersinia enterocolitica, Mycobacterium avium, Fasciola hepatica, Giardia intestinalis, and Rotavirus.
This methodology allowed ranking of 51 zoonotic agents with objectivity and taking account of a combined input from risk assessors and risk managers.
These results support food safety policy makers to establish the multiannual monitoring program of foodborne zoonoses.

The effects of transport and lairage on counts ofEscherichia coliO157 in the feces and on the hids of individual cattle
05 Nov 2009
Foodborne Pathogens and Disease. November 2009, 6(9): 1113-1120 [edited][FSNet]
Narelle Fegan, Glen Higgs, Lesley L. Duffy, Robert S. Barlow
The main objective of this study was to determine the impact of transport and lairage on the isolation rate and the number ofEscherichia coliO157 on cattle.
Ninety animals, divided into three groups (A, B, and C) of 30 animals each, were used in this study. Individual animals were tagged, and samples were collected from the hides and feces of each at a feedlot and again after slaughter. The carcass of each animal was also sampled. Samples were also collected from the feedlot pens, the sides and floors of the transport trucks, and abattoir holding pens. The isolation rate and the number ofE. coliO157 were estimated using a combination of immunomagnetic separation and the Most Probable Number technique.
Cattle hides were more likely to be contaminated withE. coliO157 at the feedlot (31%) than at the abattoir (4%).E. coliO157 was detected in 18% and 12% of cattle feces collected at the feedlot and after slaughter, respectively.E. coliO157 was isolated from truck floors (26%), truck sides (11%), abattoir pen rails (47%), and pen floors (42%).
Transport and lairage did not lead to an increase in the number or isolation rate ofE. coliO157 from cattle.
Intervention strategies for reducingE. coliO157 contamination of cattle carcasses should target mechanisms that limit the impact of animals shedding a high number throughout production and processing.

United Kingdom-Research needed onCampylobactervaccine for chickens
04 Nov 2009
Farmers Weekly Interactive [edited][FSNet]
It is becoming increasingly clear that biosecurity measures on their own are insufficient for controllingCampylobacterand that a vaccine is necessary before the industry can make significant strides in cutting its prevalence.
This has parallels withSalmonellain eggs, where commercial launch of an effective vaccine greatly assisted in eliminating it from laying flocks. Vaccines have also proved successful in the control of various epizootic viral disease such as Newcastle Disease or infectious bursal disease (Gumboro).
The interest in reducingCampylobacteris being driven by the European Commission which last year asked the European Food Safety Authority (EFSA) to consider approaches and targets to reduceCampylobacterin poultrymeat. The poultry sector is being targeted as it has been suggested that up to 85% of human infections are caused byCampylobactersfrom poultry.
Campylobacter jejuniand its close relativeC. colicommonly colonise the chicken gut in large numbers while the birds show no obvious symptoms. And these organisms contaminate carcasses during processing and can infect humans causing moderate-severe enteritis. Campylobacteriosis is now the most frequently reported cause of food poisoning in Europe.
Most intensively-reared flocks becomeCampylobacterpositive after two-three weeks of life. Studies have shown that transmission to flocks occurs horizontally from the environment via a number of routes including human traffic into the houses and possible vectors like water, rodents or flies.
Such routes could be minimised by strict biosecurity, but to date such levels of biosecurity have proved difficult to effectively introduce and maintain. Therefore, there is an increasing recognition for the need for complementary approaches, such as vaccination, to supplement biosecurity in protecting flocks fromCampylobactercolonisation.
Recent studies have demonstrated thatCampylobacterstimulates cellular responses and that they are genetically determined. This means that it may be feasible to breed future chickens that are more resistant againstCampylobacter.
Currently two strategies are generating interesting results. The first strategy involves the use of a liveSalmonellavaccine genetically engineered to incorporateCampylobacterantigens. TheSalmonellavaccine is also engineered to be quickly eliminated from the chicken's gut, so that vaccinated birds would beSalmonella-negative by slaughter.
A second strategy, using sub-unit vaccines ofCampylobacterhas been reported in the UK. Because this approach does not use GM vaccines, acceptability is not an issue. The problem with this approach is that such antigens, delivered orally, fail to generate a response at the chicken's gut surface.
In mice and humans, there are several materials (adjuvants), which can effectively present the antigens to generate an immune response at the gut surface. One such adjuvant, chitin microspheres, was able to effectively present a majorCampylobacterantigen, flagellin, to stimulate both antibody and cellular immune responses in chickens and that these responses gave protection against experimental challenge.
Both strategies provide proof that vaccination is a feasible way of protecting chickens fromCampylobacter.
To conclude, vaccination is a long-term strategy requiring considerable future investment. But given the extent of the public health issue, the difficulty in excludingCampylobacterfrom flocks and the current lack of an alternative strategy, a commitment to vaccine development may become worthwhile.

02 Nov 2009

British Food Journal, Vol 111, Issue 9, p 915-929

Sarah DeDonder, Casey J. Jacob, Brae V. Surgeoner, Benjamin Chapman, Randall Phebus, Douglas A. Powell [edited][FSNet]

The purpose of the present study was to observe the preparation practices of both adult and young consumers using frozen, uncooked, breaded chicken products, which were previously involved in outbreaks linked to consumer mishandling. The study also sought to observe behaviors of adolescents as home food preparers. Finally, the study aimed to compare food handler behaviors with those prescribed on product labels. The study sought, through video observation and self-report surveys, to determine if differences exist between consumers' intent and actual behavior. A survey study of consumer reactions to safe food-handling labels on raw meat and poultry products suggested that instructions for safe handling found on labels had only limited influence on consumer practices. The labels studied by these researchers were found on the packaging of chicken products examined in the current study alongside step-by-step cooking instructions. Observational techniques, as mentioned above, provide a different perception of consumer behaviors.

01 Nov 2009 Journal of Food Protection®, Volume 72, Number 11, pp. 2386-2389(4)

Ankolekar, Chandrakant; Labbé, Ronald G. [edited][FSNet]

Bacillus cereusis a gram-positive, spore-forming, facultative anaerobe that is responsible for two types of gastrointestinal diseases: emesis and diarrhea. A significant difference in the D95°C-values of spores of the emetic and the diarrheal types was initially determined. A mixture ofB. cereusspores of the diarrheal type was inoculated into cooked rice.

01 Nov 2009 Journal of Food Protection®, Volume 72, Number 11, pp. 2390-2393(4) Shieh, Y. Carol; Stewart, Diana S.; Laird, David T. [edited][FSNet]

Spinach leaves are frequently consumed raw and have been involved with past foodborne outbreaks. In this study, researchers examined the survival of hepatitis A virus (HAV) on fresh spinach leaves in moisture- and gas-permeable packages that were stored at 5.4 ± 1.2°C for up to 42 days.

Journal of Food Protection®, Volume 72, Number 11, pp. 2264-2271(8) Samelis, John; Giannou, Eleni; Lianou, Alexandra [edited][FSNet]

The current microbiological regulatory criteria in the European Union specify a maximumListeria monocytogenespopulation of 100 CFU/g allowable in ready-to-eat foods provided the product will not exceed this limit throughout its shelf life. The aim of this study was to validate the manufacturing method for traditional Greek Graviera cheese produced from thermized milk.

Higher rate of culture-confirmedCampylobacterinfections in Australia than in the USA: is this due to differences in healthcare-seeking behaviour or stool culture frequency?
30 Oct 2009
Epidemiology and Infection (2009), 137:1751-1758 [edited][FSNet]
H. VALLY, G. HALL, E. SCALLAN, M. D. KIRK and F. J. ANGULO
Laboratory-based surveillance by OzFoodNet in Australia and FoodNet in the USA indicated that the incidence ofCampylobacterinfections in 2001 in Australia was about nine times higher than in the USA. We assessed whether this disparity could be explained by differences in the frequency of stool culturing. Using data from population surveys of diarrhoea and symptom profiles forCampylobacterfrom case-control studies, indices of healthcare behaviour taking into account the severity ofCampylobacterinfections were calculated. These suggest that culture-confirmedCampylobacterinfections underestimate the incidence of community cases by similar ratios in the two countries. The incidence ofCampylobacterinfections in Australia was about 12 times higher than in the USA after consideration of healthcare system differences.

A modified case-control study of cryptosporidiosis (using non-Cryptosporidium-infected enteric cases as controls) in a community setting
30 Oct 2009
Epidemiology and Infection (2009), 137:1789-1799 [edited][FSNet]
K. D. M. PINTAR, F. POLLARI, et al.
Data from the first sentinel site (Waterloo Region, Ontario) of the Canadian Integrated Enteric Disease Surveillance System (C-EnterNet) were used in a secondary-based case-control study of laboratory-confirmedCryptosporidiuminfections to study the role of various exposure factors. The incidence of cryptosporidiosis in Waterloo Region was almost double both the provincial and national rates. Persons ill with one of nine other enteric infections (amoebiasis, campylobacteriosis, cyclosporiasis, giardiasis, listeriosis, salmonellosis, shigellosis, verotoxigenicE. coliinfections, yersiniosis) captured by the surveillance system were used as the control group. Of 1204 cases of enteric illness in the sentinel area between April 2005 and December 2007, 36 cases and 803 controls were selected after excluding outbreak and international travel-related cases. Results of the multivariable analysis found that cryptosporidiosis was associated with swimming in a lake or river, drinking municipal water (a potential surrogate for urban respondents vs. rural), and having a family member with a diarrheal illness.

Prevalence and antibiotic susceptibility of Listeria spp. isolated from raw meat and retail foods
24 Oct 2009
Food Control [edited][FSNet]
G. Pesavento et al.
Listeriaand particularlyListeria monocytogenesis an important foodborne pathogen that can cause listeriosis with flu-like symptoms in healthy people, and severe complications in immunocompromised subjects, children, pregnant women and the elderly. A research survey was conducted to check the presence of Listeria spp in raw meat and retail products and to analyse their antibiotic resistances. Total prevalence was 11.7%: in raw meat was 21.4%; in ham it was 5.2%; in fresh soft cheese it was 3.49%; in sandwiches it was 5.88%, while the researchers found no isolates in smoked salmon and only two in ready salads (1.23%). The highest percentage of prevalence ofListeria monocytogeneswas found in samples of ham (37.5%), lower percentages were in sandwiches (25.0%), in raw meat samples (23.6%), in fresh soft cheeses (20.0%), while ready salads and smoked salmons were not contaminated. Researchers found 51 (30.4%) strains resistant to three or more antibiotics. All isolated strains, except one, are susceptible or at least to one of the first choice antibiotics (ampicillin and gentamycin) or to trimethoprim-sulfamethoxazole used as antibiotic of second choice in the treatment of human listeriosis. Strains isolated from ready-to-eat food show high level of resistance to ampicillin, gentamycin and meticillin. Meticillin is used normally, in treatment ofEnterococcusspp. human infection;Listeria monocytogenescan transfer antibiotic resistance genes from plasmids and tranposons toEnterococcusspp. in vitro and in vivo causing an increase of these bacteria resistant to meticillin.Listeria monocytogenes, in the last decades, is becoming resistant to a lot of antibiotics, a continued surveillance on its incidence on raw foods and on emerging resistances are important to identify food that can represent a risk of infection for the population, particularly for immunocompromised, children, pregnant women and the elderly to ensure effective treatment of human listeriosis with effective antibiotics.

Prevalence and antibiotic susceptibility ofListeria spp. isolated from raw meat and retail foods
23 Oct 2009
Food Control [edited][FSNet]
Listeriaand particularlyListeria monocytogenesis an important foodborne pathogen that can cause listeriosis with flu-like symptoms in healthy people, and severe complications in immunocompromised subjects, children, pregnant women and the elderly. A research survey was conducted to check the presence ofListeria sppin raw meat and retail products and to analyse their antibiotic resistances. Total prevalence was 11.7%: in raw meat was 21.4%; in ham it was 5.2%; in fresh soft cheese it was 3.49%; in sandwiches it was 5.88%, while we found no isolates in smoked salmon and only two in ready salads (1.23%). The highest percentage of prevalence ofListeria monocytogeneswas found in samples of ham (37.5%), lower percentages were in sandwiches (25.0%), in raw meat samples (23.6%), in fresh soft cheeses (20.0%), while ready salads and smoked salmons were not contaminated. The susceptibility of 168 strains ofListeria spp. was determined by disk diffusion method: we found 51 (30.4%) strains resistant to three or more antibiotics. All isolated strains, except one, are susceptible or at least to one of the first choice antibiotics (ampicillin and gentamycin) or to trimethoprim-sulfamethoxazole used as antibiotic of second choice in the treatment of human listeriosis. Strains isolated from ready-to-eat food show high level of resistance to ampicillin, gentamycin and meticillin. Meticillin is used normally, in treatment ofEnterococcus spp. human infection;Listeria monocytogenescan transfer antibiotic resistance genes from plasmids and tranposons toEnterococcus spp. in vitro and in vivo causing an increase of these bacteria resistant to meticillin.Listeria monocytogenes, in the last decades, is becoming resistant to a lot of antibiotics, a continued surveillance on its incidence on raw foods and on emerging resistances are important to identify food that can represent a risk of infection for the population, particularly for immunocompromised, children, pregnant women and the elderly to ensure effective treatment of human listeriosis with effective antibiotics.

Campylobacterexcreted into the environment by animal sources: Prevalence, concentration shed, and host association
20 Oct 2009
Foodborne Pathogens and Disease [edited][FSNet]
Iain D. Ogden, John F. Dallas, Marion MacRae, Ovidiu Rotariu, Kenny W. Reay, Malcolm Leitch, Ann P. Thomson, Samuel K. Sheppard, Martin Maiden, Ken J. Forbes, Norval J.C. Strachan
An intensive study of 443 isolates ofCampylobacter jejuniandCampylobacter colifrom 2031 fecal samples excreted by animal sources including cattle, sheep, and pigs, a range of wild and domesticated avian species and pets is described. The prevalence found in the majority of animal sources ranged from 22% to 28% with poultry being highest at 41% and cats and dogs lowest.

Microbiological quality and safety of raw milk and soft cheese and detection of autochthonous lactic acid bacteria with antagonistic activity againstListeria monocytogenes,Salmonella spp., andStaphylococcus aureus
20.oct.09
Foodborne Pathogens and Disease [edited][FSNet]
Maria Beatriz Tassinari Ortolani, Anderson Keizo Yamazi, Paula Mendonça Moraes, Gabriela Nogueira Viçosa, Luís Augusto Nero
This study aimed to characterize the microbiological quality and safety of raw milk and soft cheese, verifying possible associations between microbial populations, and the detection of lactic acid bacteria (LAB) with antagonistic activity against foodborne pathogens. Raw milk (n=36) and soft cheese (n=18) samples were collected and submitted for the analysis of mesophilic aerobes, total coliforms,Escherichia coli,LAB, coagulase-positiveStaphylococcus(CPS),Listeria monocytogenes, andSalmonella spp. In all, 389 LAB isolates were randomly selected and submitted for antagonistic tests againstL. monocytogenes,St. aureus,SalmonellaTyphimurium, andLactobacillus sakei.The samples presented high counts of mesophilic aerobes, total coliforms, and LAB, and also high and significant correlation indices between these populations. Low levels of CPS and E. coli were observed, as well as an absence ofSalmonella spp. andL. monocytogenes. A substantial portion of the analyzed samples presented LAB cultures with antagonistic activity, but not againstSalmonellaTyphimurium. The obtained results indicate the antimicrobial potential of the autochthonous microbiota of raw milk and soft cheese. Despite the spoilage potential, the LAB present in the studied food products can be isolated and properly characterized as antagonistic cultures, to be used in bioconservation studies for pathogen control in foods.

Hemolytic uremic syndrome and death in persons withEscherichia coliO157:H7 infection, foodborne diseases active surveillance network sites, 2000-2006
17.oct.09
Clinical Infectious Diseases 2009;49:000–000 [edited][FSNet]
L. Hannah Gould, Linda Demma, Timothy F. Jones, et al
Hemolytic uremic syndrome (HUS) is a life-threatening illness usually caused by infection with Shiga toxin–producingEscherichia coliO157 (STEC O157). Researchers evaluated the age-specific rate of HUS and death among persons with STEC O157 infection and the risk factors associated with developing HUS.
Young children and females had an increased risk of HUS after STEC O157 infection. With or without HUS, elderly persons had the highest proportion of deaths associated with STEC O157 infection. These data support recommendations for aggressive supportive care of young children and the elderly early during illness due to STEC O157.

Responses ofE. coliO157:H7,L. monocytogenes4b andSalmonellaEnteritidis to pH, aw and Temperature Stress Combinations
12 Oct 2009
Food Control
Alonzo A. Gabriel, and Hiroyuki Nakano [edited][FSNet]
This study compared the responses ofE. coliO157:H7,L. monocytogenes4b andS. Enteritidis toward different combinations of physicochemical stresses (pH: 3-8; aw: 0.93-0.99; Temperature: 3-62 °C). Results showed thatL. monocytogenesgenerally had lower inactivation rates and was able to exhibit growth in most number of tested combinations, including those with very high and very low factor settings. Temperature introduced the greatest variation in the measured growth and death parameters but the contributions of both pH and aw in all temperature ranges were also noted. The results of this study may be applied in the selection of appropriate pathogens in the evaluation of safety of foods that are preserved using individual or combined physicochemical factor control.

Chemical treatment of animal feed and water for the control ofSalmonella
12 Oct 2009
Foodborne Pathogens and Disease [edited][FSNet]
Andrew D. Wales, Vivien M. Allen, Robert H. Davies
The control of Salmonella in animal feedstuffs is important, principally to protect the human food chain from contamination by Salmonella derived from infected animals. The transmission of Salmonella from animal feeds to animals, and onward to human food products, has been convincingly documented. This is especially important for chicken breeding and laying flocks and pigs, in view of the consequences of recent or imminent control legislation in the European Union. Animal feed ingredients, particularly animal and plant-derived protein meals, are frequently contaminated with Salmonella either from source or from processing plant, and recontamination in compounding mills is an additional problem. Several complementary strategies have been used to control this feed contamination, and these include a range of chemical treatments. The principal agents used are as follows: organic acids and their salts, formaldehyde, and bacterial membrane disruptors such as terpenes and essential oils. Experimental agents include chlorate compounds. Many products use blends of agents from the same or different chemical groups to achieve synergistic or combination effects. The present review draws upon published and company data to describe the various modes of action and efficacies of different chemical agents delivered in feed or in drinking water against Salmonella occurring in feed or in livestock environments. Reasons for the failure of protection are explored, along with problems in usage such as corrosion and reduced palatability. Given the wide array of products available with contrasting modes of action, the need for standardized tests of efficacy is also discussed.

Commensal fecalEscherichia colidiversity in dairy cows at high and low risk for incurring subacute ruminal acidosis
04 Oct 2009
Foodborne Pathogens and Disease. October 2009, 6(8): 973-980.
Ranjana Sharma, Krysty Munns, S. Jacob John [edited][FSNet]
Subacute ruminal acidosis (SARA) is a common digestive disorder in dairy cows characterized by prolonged periods of undesirably low rumen pH (0.05), and tet(A) allele was frequently detected among isolates from HR (45.2%) and tet(B) from LR (36.6%) cows. Changes in fecalE. coligenotypes should be explored further for its usefulness as an indicator for SARA since dairy cows are a reservoir of diverse E. coli strain types. Our results elucidate phenotypic and genotypic differences in fecalE. colished between HR and LR cows.

Survival ofSalmonellain processed chicken products during frozen storage
02 Oct 2009
Journal of Food Protection, Volume 72, Number 10, pp. 2088-2092(5)[edited][FSNet]
Dominguez, Silvia A.; Schaffner, Donald W.
Frozen chicken products have been identified recently as a cause of salmonellosis. At least eight salmonellosis outbreaks from 1998 to 2008 have implicated undercooked frozen chicken nuggets, strips, and entrees as infection vehicles. Thus, the presence ofSalmonellain frozen products may pose an infection risk if the product is improperly cooked. The objective of this study was to assess the survivability ofSalmonelladuring frozen storage (-20°) when inoculated in processed chicken products. FourSalmonellastrains originally isolated from poultry were inoculated into frozen chicken nuggets (fully cooked) and frozen chicken strips (containing raw poultry) at initial populations of 104 to 105 CFU/g. Survival was assessed during storage at -20° for 16 weeks by measuring bacterial growth on minimal, selective, and nonselective

Adherence characteristics ofListeriastrains isolated from three ready-to-eat meat processing plants
02 Oct 2009
Journal of Food Protection, Volume 72, Number 10, pp. 2125-2131(7)
Kushwaha, Kalpana; Muriana, Peter M.
Over 1,560 non-food contact surface swabs and raw meat ingredient samples were collected from three ready-to-eat meat processing plants (520 from each plant) from 1998 to 1999, resulting in the recovery of 259 isolates ofListeriaobtained from postprocess areas including drains, floors, garbage bins, cart wheels, walls, equipment surfaces, tables, brooms, pallet jacks, hoses, ladders, and waste chutes. Researchers further examined 246 of the 259 isolates for adherence phenotype and used PCR to identify those that wereListeria monocytogenes. Adherence was classified as weak, moderate, or strong depending on results obtained with allListeriaisolates by using a fluorescent microplate adherence assay. Among the 246 isolates, there were 61 weakly, 148 moderately, and 37 strongly adherentListeria, of which 130 (53%) were found to beL. monocytogenes. Adherence properties ofListeriamay allow persistence and recurrence in plant environments, potentially increasing the chance of eventual product contamination, and this emphasizes the need for sanitary approaches to prevent colonization byListeriaas well as product antimicrobial interventions should the sanitation barrier be breached.

Lack of internalization ofEscherichia coliO157:H7 in lettuce after leaf surface innoculation
02 Oct 2009
Journal of Food Protection, Volume 72, Number 10, pp. 2028-2037(10)
Zhang, Guodong; Ma, Li; Beuchat, Larry R.; Erickson, Marilyn C.; Phelan, Vanessa H.; Doyle, Michael P.
Survival and internalization characteristics ofEscherichia coliO157:H7 in iceberg, romaine, and leaf lettuce after inoculation of leaf surfaces and soil were determined. A five-strain mixture ofE. coliO157:H7 in water and cow manure extract was used as an inoculum for abaxial and adaxial sides of leaves at populations of 6 to 7 log and 4 log CFU per plant. The five strains were individually inoculated into soil at populations of 3 and 6 log CFU/g. Soil, leaves, and roots were analyzed for the presence and population ofE. coliO157:H7. Ten (4.7%) of 212 samples of leaves inoculated on the adaxial side were positive forE. coliO157:H7, whereas 38 (17.9%) of 212 samples inoculated on the abaxial side were positive.E. coliO157:H7 survived for at least 25 days on leaf surfaces, with survival greater on the abaxial side of the leaves than on the adaxial side. All 212 rhizosphere samples and 424 surface-sanitized leaf and root samples from plants with inoculated leaves were negative forE. coliO157:H7, regardless of plant age at the time of inoculation or the location on the leaf receiving the inoculum. The pathogen survived in soil for at least 60 days. Five hundred ninety-eight (99.7%) of 600 surface-sanitized leaf and root samples from plants grown in inoculated soil were negative forE. coliO157:H7. Internalization ofE. coliO157:H7 in lettuce leaves and roots did not occur, regardless of the type of lettuce, age of plants, or strain ofE. coliO157:H7.

Light helps bacteria get into lettuce (and presumably spinach, and other leafy produce)
29 Sep 2009
Los Angeles Times [edited][FSNet]
If scientists want to cut down on nasty contamination of produce, it helps to understand how bacteria end up inside the leaves of the plants, too deep to be washed off the surface.
That's what happened in theE. coliO157:H7 outbreaks in 2006 traced to bags of spinach, to name just one example, andSalmonelladoes the same trick too.
In an interesting experiment just published in the journal Applied and Environmental Microbiology, researchers reported that exposure to light makes this internal invasion more likely.
The Israeli microbiologists bought fresh iceberg lettuce from grocery stores or fields and cut the inner leaves into little pieces. These they placed in little tubes to which they addedSalmonella. After incubation, they looked at the leaves under a microscope to see where the bacteria had ended up.
The findings:Salmonellapenetrates the lettuce leaf's deeper surfaces by entering little pores called stomata. These are the pores plants use to obtain and release gases during photosynthesis--the vital process by which light energy is captured and turned into sugars. There are rather nasty pictures in the article of rod-likeSalmonellaclustered all around these stomata, seemingly going down into them and thus into the inner parts of the leaf.
Stomata tend to be open when it's light and closed when dark. The scientists repeated the experiment with lettuce disks incubated in the dark--and this time, didn't see the Salmonella gaining entry through stomata.

Survival of clinical and food isolates ofListeria monocytogenesthrough simulated gastrointestinal tract conditions
28 Sep 2009
Foodborne Pathogens and Disease [edited][FSNet]
Rosário Ramalheira, Marta Almeida, Joana Azeredo, Teresa R.S. Brandão, Gonçalo Almeida, Joana Silva, Paula Teixeira
Twenty-seven strains ofListeria monocytogenespreviously isolated from food (n=16) and human patients of listeriosis (n=11) were characterized and compared based on their ability to survive through the simulated gastrointestinal tract conditions.

Potential for growth ofClostridium perfringensfrom spores in pork scrapple during cooling
28 Sep 2009
Foodborne Pathogens and Disease [edited][FSNet]
Vijay K. Juneja, Anna C.S. Porto-Fett, Kelly Gartner, Linda Tufft, John B. Luchansky
Researchers conducted stabilization studies to determine the ability ofClostridium perfringensspores to germinate and grow during exponential cooling of a commercial formulation of pork scrapple. Scrapple must be cooled after cooking to 7.2°C within 6.5h, but for no more than 14h, to prevent a food safety hazard from outgrowth ofC. perfringensspores during cooling.

University of Toronto researchers identify how fodborne disease spreads between cells
28 Sep 2009
Daily Exchange [edited][FSNet]
University of Toronto researchers are part of an international team which has uncovered a previously unknown mechanism that plays an important role in the spread ofListeria, the trigger behind the foodborne disease listeriosis, which caused a deadly outbreak in Canada in the summer of 2008.
The research team discovered a previously unknown way in which the disease is carried from cell to cell. Their findings are published in Nature Cell Biology.
Listeria monocytogenesis a bacterium linked to food processing plants, and which can be especially debilitating or fatal for people with compromised immune systems and pregnant women. The disease moves swiftly from cell-to-cell via finger-like structures formed as the bacteria pushes out from inside one human cell to pierce into the adjacent cells.
The barrier between most cells would be strong enough to repel that cell-to-cell spread but the researchers discovered a previously unknown process that accelerates the spread of bacteria between healthy cells. A protein secreted byListeria, called InlC, softens the junction between cells, making it easier for the adjacent cells to be breached. This effect is caused by InlC inhibiting the function of a human protein known as Tuba. While InlC is unique toListeria, this work suggests that a similar mechanism may also occur during similar diseases such as Shigellosis.

Cross-contamination of fresh-cut lettuce after a short-term exposure during pre-washing cannot not be controlled after subsequent washing with chlorine dioxide and sodium hypochlorite
27 Sep 2009
Food Microbiology [edited][FSNet]
Francisco López-Gálvez, María I. Gil, P. Truchado, María V. Selma and Ana Allende
Chlorine dioxide (ClO2) has been postulated as an alternative to sodium hypochlorite (NaClO) for fresh-cut produce sanitization to avoid risks associated with chlorination by-products. Experiments were performed to determine the prevention of cross-contamination of fresh-cut lettuce byEscherichia coliusing chlorine dioxide (3 mg/L) or sodium hypochlorite (100 mg/L) as sanitation agents. The efficacy of these sanitation solutions was evaluated simulating as much as possible the conditions of a fresh-cut processing line. Thus, to evaluate the potential risk of cross-contamination during pre-washing, inoculated fresh-cut lettuce was pre-washed and after that non-inoculated lettuce was then pre-washed in the same water. After this pre-washing, non-inoculated lettuce was cross-contaminated, changing from 0 to 3.4 log units ofE. colicells. During washing with sanitizers, none of the tested sanitation agents significantly reducedE. colicounts in both inoculated and cross-contaminated lettuce. These results suggest that when cross-contamination occurs, even if the event is recent, subsequent sanitation steps are inefficient for inactivatingE. colicells on the vegetable tissue. However, chlorine dioxide and sodium hypochlorite solutions were able to inactivate most E. coli cells that passed from inoculated product to wash water. Therefore, they might be able to avoid cross-contamination between clean and contaminated product during the washing step. Scanning electron microscopy micrographs indicated that bacterial cells were mainly located in clusters or tissue stomata where they might be protected, which explains the low efficacy of sodium hypochlorite and chlorine dioxide solutions observed in this study.

Human health consequences of use of antimicrobial agents in aquaculture
23 Sep 2009
Clinical Infectious Diseases 2009;49:000–000 [edited][FSNet]
Ole E. Heuer, Hilde Kruse, Kari Grave, P. Collignon, Iddya Karunasagar, and Frederick J. Angulo
Intensive use of antimicrobial agents in aquaculture provides a selective pressure creating reservoirs of drug-resistant bacteria and transferable resistance genes in fish pathogens and other bacteria in the aquatic environment. From these reservoirs, resistance genes may disseminate by horizontal gene transfer and reach human pathogens, or drug-resistant pathogens from the aquatic environment may reach humans directly. Horizontal gene transfer may occur in the aquaculture environment, in the food chain, or in the human intestinal tract. Among the antimicrobial agents commonly used in aquaculture, several are classified by the World Health Organisation as critically important for use in humans. Occurrence of resistance to these antimicrobial agents in human pathogens severely limits the therapeutic options in human infections. Considering the rapid growth and importance of aquaculture industry in many regions of the world and the widespread, intensive, and often unregulated use of antimicrobial agents in this area of animal production, efforts are needed to prevent development and spread of antimicrobial resistance in aquaculture to reduce the risk to human health.

Fate ofListeria monocytogenesduring freezing, thawing and home storage of frankfurters
22 Sep 2009
Food Microbiology [edited][FSNet]
C. Simpson Beauchamp, O.A. Byelashov, I. et al.
Little information is available regarding the fate ofListeria monocytogenesduring freezing, thawing and home storage of frankfurters even though recent surveys show that consumers regularly store unopened packages in home freezers. The study examined the effects of antimicrobials, refrigerated storage, freezing, thawing method, and post-thawing storage (7°C) onL. monocytogeneson frankfurters.

Antimicrobial resistance profiling and molecular subtyping ofCampylobacterspp. from processed turkey
21 Sep 2009
BMC Microbiology 2009, 9:203 [edited][FSNet]
Ellen Lutgen, John McEvoy, Julie Sherwood, Catherine Logue
Campylobacteris a major cause of human disease worldwide and poultry are identified as a significant source of this pathogen. Most disease in humans is associated with the consumption of contaminated poultry or cross-contamination with other foods.
The primary drugs of choice for treatment of human campylobacteriosis include erythromycin and ciprofloxacin. In this study, the researchers investigated the prevalence of resistance to erythromycin and ciprofloxacin inCampylobacterisolates recovered from turkey carcasses at two processing plants in the Upper Midwest US.
Further analysis of a subset of isolates was carried out to assess resistance and genotype profiles.
Ciprofloxacin and erythromycin resistance inCampylobacterrecovered from processed turkey occurred more frequently amongC. colithanC. jejuni. Fla-PFGE types were associated with a particular species, antimicrobial resistance profiles, and a specific plant.
Molecular subtyping in this study provided more information about the relationships among antimicrobial-resistantCampylobacterat the processing level.

Can stress in farm animals increase food safety risk?
08 Sep 2009
Foodborne Pathogens and Disease. September 2009, 6(7): 767-776. [edited][FSNet]
All farm animals will experience some level of stress during their lives. Stress reduces the fitness of an animal, which can be expressed through failure to achieve production performance standards, or through disease and death. Stress in farm animals can also have detrimental effects on the quality of food products. However, although a common assumption of a potential effect of stress on food safety exists, little is actually known about how this interaction may occur. The aim of this review was to examine the current knowledge of the potential impact of stress in farm animals on food safety risk. Colonization of farm animals by enteric pathogens such asEscherichia coliO157:H7,Salmonella, andCampylobacter, and their subsequent dissemination into the human food chain are a major public health and economic concern for the food industries. This review shows that there is increasing evidence to demonstrate that stress can have a significant deleterious effect on food safety through a variety of potential mechanisms. However, as the impact of stress is difficult to precisely determine, it is imperative that the issue receives more research attention in the interests of optimizing animal welfare and minimizing losses in product yield and quality, as well as to food safety risks to consumers. While there is some evidence linking stress with pathogen carriage and shedding in farm animals, the mechanisms underlying this effect have not been fully elucidated. Understanding when pathogen loads on the farm are the highest or when animals are most susceptible to infection will help identifying times when intervention strategies for pathogen control may be most effective, and consequently, increase the safety of food of animal origin.

The claim: Cinnamon oil kills bacteria
08 Sep 2009
New York Times [edited][FSNet]
In a country obsessed with germs and sickness, antibacterial soaps and sanitizers are becoming more and more common. But because such products contribute to the growing problem of antibiotic-resistant bacteria, some researchers recommend sanitizers made with cinnamon oil, which has been shown in many studies to have powerful antimicrobial properties.
A recent study by a team of surgeons, for example, found that a solution made with cinnamon oil killed a number of common and hospital-acquired infections, likeStreptococcusand methicillin-resistantStaphylococcus aureus, or MRSA. The study found it was just as effective as several antiseptics widely used in hospitals. Another study by French researchers in 2008 had similar results, showing that at concentrations of 10 percent or less, cinnamon oil was effective againstStaphylococcus, E. coliand several antibiotic-resistant strains of bacteria.
Cinnamon oil, when applied topically, is generally safe. But in some people it can cause an allergic reaction.

Scale-up seed decontamination process to inactivate Escherichia coli O157:H7 and Salmonella enteritidis on mung bean seeds
07 Sep 2009
Foodborne Pathogens and Disease [edited][FSNet]
A majority of the seed sprout–related outbreaks have been associated withEscherichia coliO157:H7 andSalmonellaspp. Therefore, it is necessary to find an effective method to inactivate these microorganisms on the seeds before sprouting. When treatment with hot water at 85°C for 40sec followed by dipping in cold water for 30sec and soaking into chlorine water (2000ppm) for 2h was performed, no viable pathogens were found in the enrichment medium and during the sprouting process. The germination yield of the seed was not affected significantly (p>0.05). Therefore, these treatments could be useful for the decontamination method of mung bean seeds intended for sprout production.

Evidence- based semiquantitative methodology for prioritization of foodborne zoonoses
28 Aug 2009
Foodborne Pathogens and Disease, Vol 6, Number 9 [edited][FSNet]
Abstract
Objectives: To prioritize an extended list of food- and water-borne zoonoses to allow food safety authorities to focus on the most relevant hazards in the food chain.
Methods: An evidence-based semiquantitative methodology was developed. Scores were given by 35 scientific experts in the field of animal and public health, food, and clinical microbiology and epidemiology to 51 zoonotic agents according to five criteria related to public health (severity and occurrence in humans), animal health (severity of disease coupled with economic consequences and occurrence in animals), and food (occurrence in food). The scoring procedure was standardized and evidence-based as experts were provided, for each zoonotic agent, a same set of up-to-date help information data related to the five criteria. Independently, the relative importance of the five criteria was weighted by seven food chain risk managers. The zoonotic agents were ranked based on overall weighted scores and were grouped in four statistically different levels of importance.
Results: The following foodborne zoonotic pathogens were classified as “most important”:Salmonella spp.,Campylobacter spp.,Listeria monocytogenes, and verocytotoxigenicEscherichia coli. A second group of “significant importance” includedToxoplasma gondii, the agent of bovine spongiform encephalopathy,Clostridium botulinum,Staphylococcus aureus,Cryptosporidium parvum,Mycobacterium bovis,Echinococcus granulosus,Streptococcus spp.,Echinococcusmultilocularis,Yersinia enterocolitica,Mycobacterium avium,Fasciola hepatica,Giardia intestinalis, and Rotavirus.
These results support food safety policy makers to establish the multiannual monitoring program of foodborne zoonoses. They also enable to identify knowledge gaps on specific zoonotic agents and to formulate key research questions. Principally, this method of prioritization is of general interest as it can be applied for any other ranking exercise and in any country.

Efficacy of oregano oil in the inactivation ofSalmonellaTyphimurium on lettuce
04 Aug 2009
Food Control [edited][FSNet]
Abstract
This study was conducted to determine the efficacy of oregano oil in the inactivation ofSalmonellaTyphimurium inoculated onto iceberg lettuce. The effect of washing with oregano oil (Oreganum onites), typical of Turkey, at three different concentrations and four different treatment times on survival ofS. Typhimurium inoculated to fresh cut iceberg lettuce were determined at 20 °C and compared with a 50 ppm chlorine wash at the same conditions. The spot and dip inoculation methods for applying inoculum to iceberg and romaine type lettuce were evaluated and the effects of selective and nonselective media on the recovery ofS. Typhimurium were also examined. Populations ofS. Typhimurium recovered from spot and dip inoculated lettuce were not significantly different (p>0.05). No significant differences were found between two different media, and two different lettuce types (p>0.05). Reductions ofS. Typhimurium by washing with oregano did not exceed 1.92 logarithmic units regardless of the washing times and concentrations. The effectiveness of washing lettuce with 75 ppm oregano oil on inactivation ofS. Typhimurium was comparable with that affected by 50 ppm chlorine. The results suggested that oregano oil might be a suitable decontamination alternative to chlorine for lettuce.

Thermal inactivation ofSalmonellain peanut butter
August 2009
Journal of Food Protection [edited][FSNet]
The objective of the study was to determine the rates of thermal inactivation of threeSalmonellaTennessee strains in peanut butter associated with an outbreak and to compare them to the rates of inactivation ofSalmonellastrains of other serotypes (Enteritidis, Typhimurium, and Heidelberg) (SSOS) and of clinical isolates ofSalmonellaTennessee from sporadic cases (STSC). Commercial peanut butter was inoculated withSalmonellaisolates and heated at 71, 77, 83, and 90°C. The results indicate that the outbreak-associatedSalmonellastrains were more thermotolerant than the otherSalmonellastrains tested, and this greater thermal resistance was not serotype specific. Thermal treatments of peanut butter at 90°C for less than 30 min are not sufficient to kill large populations (5 log CFU/g) ofSalmonellain highly contaminated peanut butter.

Effects of tenderizers combined with organic acids onEscherichia coliO157:H7 thermal resistance in non-intact beef
31 Jul 2009
International Journal of Food Microbiology, Volume 133, Issues 1-2, Pages 78-85 [edited] [FSNet]
Non-intact beef products include beef cuts that have been ground, mechanically tenderized, restructured, or have been injected with solutions to enhance tenderness and/or flavor. This study examined the effects of tenderizing salts and organic acids on thermal inactivation ofEscherichia coliO157:H7 in a ground beef model system simulating non-intact beef products.

Evidence of class 1 integron transfer betweenEscherichia coliandSalmonellaspp. on livestock farms
24 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
A study was conducted to determine if homologous integrons occurred inEscherichia coliandSalmonellaspp. within livestock production sites in the United States and Thailand suggesting transfer of genetic resistance elements between those organisms. Fecal samples were collected via rectal swabs from live swine in the United States and Thailand, and cloacal swabs from live chickens in Thailand, and killed chickens at a U.S. abattoir. Isolates were derived only from farms harboring bothSalmonellaandE. coli,resulting in the inclusion of 571E. coliand 98Salmonellaisolates derived from both livestock species in the United States and Thailand. Our results indicate that while in most cases, integrons of coexistingE. coliandSalmonelladiffered, identical integron amplicons were found in those species from a single swine farm in Thailand, suggesting horizontal transfer between these two organisms may have occurred on-farm.

The effect of transport and lairage on counts ofEscherichia coliO157 in the feces and on the hides of individual cattle
24 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
Objectives:The main objective of this study was to determine the impact of transport and lairage on the isolation rate and the number ofEscherichia coliO157 on cattle.
Conclusions:Transport and lairage did not lead to an increase in the number or isolation rate ofE. coliO157 from cattle.
Applications:Intervention strategies for reducingE. coliO157 contamination of cattle carcasses should target mechanisms that limit the impact of animals shedding a high number throughout production and processing.

Effectiveness of sanitizers, dry heat, hot water, and gas catalytic infrared heat treatments to inactivateSalmonellaon almonds
21 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
Abstract
The majority of almond-related foodborne outbreaks have been associated withSalmonella. Therefore, it is necessary to find an effective method to inactivate these organisms on raw almond prior to market distribution. This study was conducted to assess the effectiveness of sanitizers (strong or mild electrolyzed water, ozonated water, and distilled water), dry heat treatment, and hot water treatments followed by catalytic infrared (IR) heat treatment to inactivateSalmonellapopulations on raw almond. Raw almonds inoculated with four-strain cocktails ofSalmonellawere treated either by soaking in different chemical sanitizers or with dry heat and/or hot water for various periods of time followed by catalytic IR heat treatment for 70 seconds. The treated seeds were then assessed for the efficacy of the treatment in reducing populations of the pathogens. After inoculation and air-drying, 5.73±0.12 log colony-forming units (CFU)/gSalmonellawere detected in nonselective medium. Sanitizer treatment alone did not show significant reduction in theSalmonellapopulation, but in combination with IR drying it reduced the population to 3.0 log CFU/g. Dry heating at 60°C for 4 days followed by IR drying for 70 seconds reduced theSalmonellapopulation an additional 1.0log CFU/g. Hot water treatments at 85°C for 40 seconds followed by IR drying for 70 seconds reduced pathogens to an undetectable level by direct plating, but not by enrichment.

Occurrence and characterization ofAeromonas hydrophilaandYersinia enterocoliticain minimally processed fresh vegetable salads
18 Jul 2009
Science Direct [edited][FSNet]
A range of commercially available minimally processed ready to eat salads was examined for the presence ofAeromonasandYersinia,to provide information about their occurrence and characterize them by some phenotypic criteria. The SDS-PAGE of whole-cell proteins was also applied as a taxonomic tool for the rapid and effective identification ofAeromonas hydrophilaandYersinia enterocoliticafound among a number ofAeromonasandYersiniaisolates. The results suggest the prevalence ofA. hydrophilaisolates and the low occurrence ofY. enterocoliticain the minimally processed salads.

Escherichia coliO157:H7 vaccine dose-effect in feedlot cattle
12 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
A clinical trial conducted during the summer of 2006 evaluated effects of two- and three-dose regimens of an Escherichia coli O157 vaccine product on the probability of detectingE. coliO157:H7 in feces and colonization of the terminal rectum. The three-dose regimen significantly reduced the probability for cattle to shedE. coliO157:H7 in feces 65% compared to placebo-treated cattle. A dose–effect was demonstrated because a two-dose regimen of the vaccine product was intermediate in effect. These results are consistent with previous estimates of vaccine efficacy against fecal shedding, and agree with our previous finding that efficacy of two or three doses of this vaccine product exhibit a dose–response.

Dietary interactions and interventions affectingEscherichia coliO157 colonization and shedding in cattle
11 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
Escherichia coliO157 is an important foodborne pathogen affecting human health and the beef cattle industry. Contamination of carcasses at slaughter is correlated to the prevalence ofE. coliO157 in cattle feces. Many associations have been made between dietary factors andE. coliO157 prevalence in cattle feces. Preharvest interventions, such as diet management, could reduce the fecal prevalence and diminish the impact of this adulterant. Dietary influences, including grain type and processing method, forage quality, and distillers grains have all been associated withE. coliO157 prevalence. In addition, several plant compounds, including phenolic acids and essential oils, have been proposed as in-feed intervention strategies. The specific mechanisms responsible for increased or decreasedE. coliO157 shedding or survival are not known but are often attributed to changes in hindgut ecology induced by diet types. Some interventions may have a direct bacterial effect. Frequently, results of studies are conflicting or not repeatable, which speaks to the complexity of the hindgut ecosystem, variation in animal feed utilization, and variation within feed products. Still, understanding specific mechanisms, driven by diet influences, responsible forE. coliO157 shedding will aid in the development and implementation of better and practical preharvest intervention strategies.

A randomized longitudinal trial to test the effect of regional vaccination within a cattle feedyard onEscherichia coliO157:H7 rectal colonization, fecal shedding, and hide contamination
11 Jul 2009
Foodborne Pathogens and Disease [edited][FSNet]
We tested the efficacy of vaccinating all cattle within a region of a cattle feedlot using a two-dose regimen of a vaccine against type III secreted proteins ofEscherichia coliO157:H7. Cattle (n=504) were randomly assigned to 63 pens (8 steers/pen) within 3 treatment regions of the feedyard. All pens within each region were assigned: (1) two doses of vaccine, (2) two doses of adjuvant as placebo, or (3) commingled vaccination. Binary outcomes were (1) fecal shedding ofE. coliO157:H7 42, 63, and 84 days postvaccination (dpv), (2) hide contamination 42, 63, and 84dpv, and at the abattoir 85dpv, and (3) colonization of the terminal rectal mucosa at the abattoir 85dpv. For each outcome, multilevel logistic regression tested the effect of regional vaccination (ALLVAC vs. NOVAC), and compared commingled vaccinated versus placebo-treated cattle within HALFVAC pens. For fecal shedding, regional vaccine efficacy of ALLVAC compared to NOVAC pens was 63% (OR=0.34, p=0.0009), similar to vaccine efficacy of 52% for vaccinated cattle compared to placebo-treated cattle within HALFVAC pens (OR=0.48, p=0.014). For hide contamination, vaccine efficacy was 55% for regional vaccination of cattle in ALLVAC pens compared to NOVAC pens (OR=0.43, p=0.014). However, commingling vaccinated and placebo-treated cattle was not protective of hide contamination (OR=0.67, p=0.33). Colonization of cattle at the abattoir was not different among vaccinated and placebo-treated cattle (p=0.63). We concluded that the two-dose vaccine regimen effectively reducedE. coliO157:H7 fecal shedding and hide contamination, and that vaccination of cattle within regions of the feedyard provided greater protection against hide contamination than commingling vaccinates and nonvaccinates.

Association ofEscherichia coliO157:H7 with filth flies (muscidaeandcalliphoridae) captured in leafy greens fields and experimental transmission ofE. coliO157:H7 to spinach leaves by house flights (diptera:muscidae)
09 Jul 2009
Journal of Food Protection [edited][FSNet]
The recent outbreak ofEscherichia coliO157:H7 infection associated with contaminated spinach led to an investigation of the role of insects, which frequent fields of leafy greens and neighboring rangeland habitats, in produce contamination. Four leafy greens fields adjacent to cattle-occupied rangeland habitats were sampled using sweep nets and sticky traps. Agromyzid flies, anthomyiid flies, and leafhoppers were caught consistently in both rangeland and leafy greens production fields at all sites. An unexpected number of flies (n = 34) in theMuscidaeandCalliphoridaefamilies (known as filth flies because of their development in animal feces) were caught in one leafy greens field. A subset of these filth flies were positive (11 of 18 flies) forE. coliO157:H7 by PCR amplification using primers for theE. coliO157:H7-specific eae gene. Under laboratory conditions, house flies were confined on manure or agar medium containingE. coliO157:H7 tagged with green fluorescent protein (GFP) and then tested for their capacity to transfer the microbes to spinach plants. GFP-tagged bacteria were detected on surfaces of 50 to 100% of leaves examined by fluorescence microscopy and in 100% of samples tested by PCR. These results indicate that flies are capable of contaminating leafy greens under experimental conditions and confirm the importance of further investigation of the role of insects in contamination of fresh produce.

Microbial antagonists ofEscherichia coliO157:H7 on fresh-cut lettuce and spinach
09 Jul 2009
Journal of Food Protection [edited][FSNet]
Fresh-cut lettuce and spinach can become contaminated with pathogens at numerous points from the field to the retail market. Natural microflora present on fresh produce may help reduce the pathogen load. The objective of this study was to isolate natural microflora from fresh-cut iceberg lettuce and baby spinach and to determine whether these bacteria were antagonistic towardEscherichia coliO157:H7. Samples were collected under conditions that mimicked actual practices between production and retail sale. Evidence of naturally occurring microorganisms on fresh lettuce (295 isolates) and spinach (200 isolates) and of possible antagonistic activity towardE. coliO157:H7 was documented. Inhibitory activity by several isolates was due to either acid production or antimicrobial peptides. Bacteria with inhibitory activity were isolated from every step in the processing and handling of the fresh-cut iceberg lettuce and baby spinach.

Effectiveness of bacteriophages in reducingEscherichia coliO157:H7 on fresh-cut cantaloupes and lettuce
09 Jul 2009
Journal of Food Protection [edited][FSNet]
Consumption of produce contaminated withEscherichia coliO157:H7 has resulted in cases of foodborne illness. We determined the efficacy of a mixture of threeE. coliO157:H7-specific bacteriophages (ECP-100) in reducing the number of viableE. coliO157:H7 on contaminated fresh-cut iceberg lettuce and cantaloupe.

Interaction ofEscherichia coliO157:H7 with leafy green produce
09 Jul 2009
Journal of Food Protection [edited][FSNet]
EnterohemorrhagicEscherichia coli(EHEC) is a foodborne pathogen responsible for human diarrheal disease. EHEC lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. Human infections are associated with consumption of tainted animal products and fresh produce. How the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. The goals of the present study were to investigate the environmental conditions and surface structures that influence the interaction of EHEC O157:H7 with baby spinach and lettuce leaves in vitro. Independently of the production of Shiga toxin, EHEC O157:H7 colonizes the leaf surface via flagella and the type 3 secretion system (T3SS). Ultrastructural analysis of EHEC-infected leafy greens revealed the presence of flagellated bacteria, and mutation of the fliC flagellin gene in EHEC EDL933 rendered the bacteria significantly less adherent, suggesting the involvement of flagella in the bacteria-leaf interaction. EDL933 mutated in the escN (ATPase) gene associated with the function of the T3SS but not in the eae (intimin adhesin) gene required for adherence to host intestinal cells had significantly reduced adherence compared with that of the parental strain. The data suggest a compelling role of flagella and the T3SS in colonization of leafy green produce. Colonization of salad leaves by EHEC strains may be a strategy that ensures survival of these bacteria in the environment and allows transmission to the human host.

Risk assessment forClostridium perfringensin ready-to-eat and partially cooked meat and poultry products
09 Jul 2009
Journal of Food Protection [edited][FSNet]
An assessment of the risk of illness associated withClostridium perfringensin ready-to-eat and partially cooked meat and poultry products was completed to estimate the effect on the annual frequency of illnesses of changing the allowed maximal 1-log growth ofC. perfringensduring stabilization (cooling after the manufacturing heat step). The exposure assessment modeled stabilization, storage, and consumer preparation such as reheating and hot-holding. The model predicted that assuming a 10- or 100-fold increase from the assumed 1-log (maximal allowable) growth ofC. perfringensresults in a 1.2- or 1.6-fold increase ofC. perfringens-caused illnesses, respectively, at the median of the uncertainty distribution. Improper retail and consumer refrigeration accounted for approximately 90% of the 79,000C. perfringensillnesses predicted by the model at 1-log growth during stabilization. Improper hot-holding accounted for 8% of predicted illnesses, although model limitations imply that this is an underestimate. Stabilization accounted for less than 1% of illnesses. Efforts to reduce illnesses fromC. perfringensin ready-to-eat and partially cooked meat and poultry products should focus on retail and consumer storage and preparation methods.

Use of the systems approach to determine the fate ofEscherichia coliO157:H7 on fresh lettuce and spinach
09 Jul 2009
Journal of Food Protection [edited][FSNet]
Lettuce and spinach inoculated withEscherichia coliO157:H7 were processed and handled in ways that might occur in commercial situations, including variations in holding times before and after product cooling, transportation conditions and temperatures, wash treatments, and product storage temperatures and times. Populations of background microflora andE. coliO157:H7 were enumerated after each step in the system. Data analysis was done to predict response variables with a combination of independent categorical variables. Field temperature, time before cooling, and wash treatment significantly affectedE. coliO157:H7 populations on both products. The lowest populations ofE. coliO157:H7 were encountered when precool time was minimal, lettuce was washed with chlorine, and storage temperature was 4°C. For lettuce, field and transportation temperature were not important once the storage period started, whereas after 2 daysE. coliO157:H7 populations on packaged baby spinach were not affected by field temperature. On chopped iceberg lettuce and whole leaf spinach that was packaged and stored at 4°C,E. coliO157:H7 contamination could still be detected after typical handling practices, although populations decreased from initial levels in many cases by at least 1.5 log units. In abusive cases, where populations increased, the product quality quickly deteriorated. AlthoughE. coliO157:H7 levels decreased on products handled and stored under recommended conditions, survivors persisted. This study highlights practices that may or may not affect the populations ofE. coliO157:H7 on the final product.

Inactivation ofEscherichia coliO157:H7 and natural microbiota on spinach leaves using gaseous ozone during vacuum cooling and simulated transportation
09 Jul 2009
Journal of Food Protection [edited][FSNet]
The aim of this study was to integrate an ozone-based sanitization step into existing processing practices for fresh produce and to evaluate the efficacy of this step againstEscherichia coliO157:H7. Baby spinach inoculated withE. coliO157:H7 was treated in a pilot-scale system with combinations of vacuum cooling and sanitizing levels of ozone gas. The contribution of process variables (ozone concentration, pressure, and treatment time) to lethality was investigated using response-surface methodology. Ozone gas processes decreasedE. coliO157:H7 populations by up to 2.4 log CFU/g. The treatment decreasedE. colipopulations by up to 1.4 log CFU/g, and the optimum process resulted in a 1.0-log inactivation with minimal effect on product quality. In a third group of experiments, freshly harvested unprocessed spinach was inoculated withE. coliO157:H7 and sequentially subjected to optimized SanVac and SanTrans processes. This double treatment inactivated 4.1 to =5.0 log CFU/g, depending on the treatment time. These novel sanitization approaches were effective in considerably reducing the E. coli O157:H7 populations on spinach and should be relatively easy to integrate into existing fresh produce processes and practices.

Economic assessment of food safety standards: Costs and benefits of alternative approaches
07 July 2009
Food Control [edited][FSNet]
This article provides an overview of economic methods to measure costs and benefits related to food safety issues. After an introduction on general economic principles, including the distinction between social and private costs and benefits, the article highlights the various methods for calculation of costs and benefits, including “willingness to pay”, amongst others. Particular attention is paid to the “quality-adjusted life years“(QALY) method for quantitatively expressing health impacts. The practice of Regulatory Impact Assessments as carried out by the UK authorities is explored in more detail as an example of cost-benefit analysis of regulatory measures. The applicability of the approaches to the various stages of the SAFE FOODS model is highlighted.

Prevalence, persistance, and control ofSalmonellaandListeriain shrimp and shrimp products: a review
07 Jul 2009
Food Control [edited][FSNet]
Shrimp are an important commodity in the international fisheries trade and there is an indication of an increase in worldwide consumption of this crustacean.SalmonellaandListeriahave been isolated from shrimps and shrimp products on a regular basis since the 1980s. The continued reporting of the presence of these pathogens in fresh and frozen shrimps, and even in the lightly preserved and ready-to-eat products, indicates that the existing practices used by the manufacturers or processors are insufficient to eliminate these pathogens. This paper reviews the information available onSalmonellaandListeriain shrimp and makes recommendations on control options and avenues for future research in order to improve shrimp safety and quality.

Designing effective messages for microbial food safety hazards
07 Jul 2009
Food Control [edited][FSNet]
Despite numerous food safety information campaigns and educational efforts, microbial foodborne illness remains a significant source of human disease. New food safety messages transmitted using new media are required to enhance food safety from farm-to-fork. A review of the literature reveals that targeting a segment of the population and understanding knowledge, attitudes, and perceptions of the individuals comprising that segment can lead to successful communication of food safety messages. Messages found to be effective are relevant to the target audience, contain reliable information, are rapidly distributed at appropriate times, and are repeated. Those containing information that is easily received and understood have also been found effective. The use of media commonly accessed by today’s consumers is also valuable. Evaluation of the effect of all aspects of food safety messages and media, as measured through observation of recipients’ actions, is required to validate the effectiveness of food safety communications.

Impacts of individual animal response to heat and handling stresses onEscherichia coliandE. coliO157:H7 fecal shedding by feedlot cattle
Foodborne Pathogens and Disease [edited][FSNet]
The reduction of foodborne pathogens in cattle destined for human consumption will require knowledge of the factors that impact the carriage and shedding of these organisms. The objective of this work was to investigate the effects of heat and handling stress levels on the fecal shedding ofEscherichia coliO157:H7 and genericE. coliby feedlot cattle. In year 1, 128 feedlot heifers were evaluated for heat tolerance five times per week during the 84-day finishing period from May through August. Heat stress measurements included respiration rate, panting score, and visual assessments. In year 2, panting scores were taken for a group of 256 finishing feedlot heifers on days in July and August for which the temperature humidity index (THI) was predicted to be in the “emergency” category (THI=84). For both years, animals were weighed and temperament scored to assess handling stress on a 28-day schedule. At the same time, rectal fecal samples were collected from each animal individually. The presence and concentrations ofE. coliO157:H7 and concentrations of genericE. coliin feces were determined. There were no clear trends between the heat stress levels or temperament scores (as an indicator of response to handling) with either fecal genericE. coliconcentrations orE. coliO157:H7 concentrations or prevalence in feces, indicating that neither heat nor handling stress contributes to the food safety risk associated withE. coliO157:H7-positive cattle.

Plant protein "doorkeepers" block invading microbes, study finds
28 Jun 2009
University of California-Davis [edited] [FSNet]
A group of plant proteins that "shut the door" on bacteria that would otherwise infect the plant's leaves has been identified for the first time by a team of researchers in Denmark, at the University of California, Davis, and at UC Berkeley.
Findings from the study, which will appear June 29 in the online journal Public Library of Science Biology, provide a better understanding of plants' immune systems and will likely find application in better protecting agricultural crops and horticultural plants against diseases.
Plants are continually exposed to bacteria, viruses and other microorganisms, many of which have the ability to infect the plant and cause disease.
Animals have what are known as innate, or preformed, immune systems as well as adaptive immune systems that learn to recognize and defend against disease-causing microbes. Plants, however, only have innate immune systems. Rather than developing immunity as they are exposed to various microbes, plants make use of certain built-in cells and genetically programmed systems to protect themselves against microbial invasion and related diseases.
This type of innate immune system has two branches: one makes use of receptor proteins outside the cell to recognize specific molecular features of an invading microbe, while the other branch uses similar proteins within the cell to recognize an invading microbe during the infection process.
Up until now, scientists had identified only one protein, known as RIN4, which is able to regulate these two branches of the plant immune system in Arabidopsis. The protein is found in the permeable plasma membrane that encases the cell on the inside of the cell wall. It has been unclear exactly how the protein and the two branches of the immune system interact to trigger an immune response in the plant.
In studying the RIN4 protein, researchers identified six previously uncharacterized proteins that can associate with RIN4 inside plant cells. One protein, called AHA1, was characterized in-depth and found to be key to the immune response in Arabidopsis plants.
AHA1 can act to regulate the opening and closing of tiny holes called stomata, found on the underside of the leaf. The stomata allow gases and water to pass in and out of the leaf. This is the same opening that allows bacteria and other invading microbes to gain entrance to the plant.
The stomata are each flanked by two guard cells, which control these vitally important portals to the leaf. When the guard cells swell, the stomata close. Conversely, when the water content of the guard cells decreases, the stomata open.
The six proteins identified in this study were found to be intricately involved with the biochemical processes that enable the plant to recognize and block out invading bacteria. The researchers found that RIN4 can act to regulate AHA1 and that both proteins work together to control stomatal openings in response to a disease-causing microorganism.

Food safety drive tough on smaller companies-study
24 Jun 2009
Reuters [edited] [FSNet]
Food safety checks designed to prevent dangerous contamination are making it difficult for smaller businesses to compete against larger rivals, two U.N. agencies said in a report obtained by Reuters on Wednesday.
The Food and Agriculture Organisation (FAO) and World Health Organisation (WHO) study said producers, processors and exporters in developing states were struggling to cope with new and overlapping requirements.
The report for next week's meeting in Rome of the Codex Alimentarius Commission, a joint WHO and FAO body on food safety, said industry moves to introduce voluntary rules on top of government oversight had produced mixed results.
"To the extent that there are economies of scale in compliance and/or larger firms are better able to access finance and other resources, compliance processes are likely to induce processes of consolidation and concentration," said the study.
The document was also discussed on Wednesday at the World Trade Organisation.
The biggest constraints were being felt in poorer nations. The WHO/FAO study said small players may need assistance to avoid being squeezed out of the market by the drive to sanitize the food chain.
"Exporters of fresh fruit and vegetables, meat, dairy and seafood must comply with multi-tiered requirements including quality grades and standards, traceability requirements, labels of origin, phytosanitary controls and food safety standards, of both a regulatory and private nature," it said.

Survival and growth of Salmonella enteriditis in liquid egg products varying by temperature, product composition, and carbon dioxide concentration
June 2009
Foodborne Pathogens and Disease. June 2009, 6(5): 561-567
Cryogenic cooling of shell eggs with carbon dioxide (CO2) is known to improve egg content quality through rapid cooling as well as by increasing internal CO2 levels. A study was undertaken to determine the effects of variations in atmospheric CO2 concentrations (aerobically stored, flushed with CO2 and sealed, or bubbled with CO2) on the survival and growth ofSalmonellaEnteritidis in liquid egg products including whole egg, albumen, yolk, and albumen+1% yolk. Salmonella populations differed based on variations in liquid egg composition (p0.05) in yolk-containing egg products or affect the inhibitory activity of albumen-containing products.

Efficacy of chlorine and acidified sodium chlorite on microbial population and quality changes of spinach leaves
June 2009
Foodborne Pathogens and Disease June 2009, Vol. 6, No. 5: 541-546 [edited] [FSNet]
Efficacy of washing with distilled water, chlorine solution, and acidified sodium chlorite (ASC) solution on populations of microorganisms on spinach leaves was evaluated. Washing with chlorine and ASC (sodium chlorite; citric acid) resulted in significant population reduction of aerobic microflora, coliform, andEscherichia coliO157:H7.

Prevalence of zoonotic or potentially zoonotic bacteria, antimicrobial resistance, and somatic cell counts in organic dairy production: Current knowledge and research gaps
June 2009
Foodborne Pathogens and Disease June 2009, Vol. 6, No. 5: 525-539. [edited] [FSNet]
The review's objective was to identify, evaluate, and summarize the findings of all primary research published in English or French, investigating prevalence of zoonotic or potentially zoonotic bacteria, bacterial resistance to antimicrobials, and somatic cell count (SCC) in organic dairy production, or comparing organic and conventional dairy production, using a systematic review methodology. Among 47 studies included in the review, 32 comparison studies were suitable for quality assessment. Fifteen studies were not assessed for quality, due to their descriptive nature or a low sample size (n=2 farms). Overall, bacterial outcomes were reported in 17 studies, and prevalence of antimicrobial resistance (AMR) and multidrug resistance (MDR) of zoonotic or potentially zoonotic bacteria in 12 and 7 studies, respectively.Campylobacterspp.,Escherichia coliincluding Shiga toxin–producing strains,Salmonellaspp.,Staphylococcus aureus, and SCC were investigated in 2, 7, 4, 6, and 15 studies, respectively. Contradictory findings were reported for differences in bacterial outcomes and SCC between dairy production types (organic vs. conventional). Lower prevalence of AMR on organic dairy farms was reported more consistently in studies conducted in the United States, as opposed to those conducted in Europe. These conflicting findings may result from geographic differences in organic production regulations governing antimicrobial usage, use of antimicrobials in conventional dairy production, and baseline prevalence, as well as laboratory methods, study designs, or methods of analysis employed. The majority (four of seven) of MDR investigations reported no significant differences in prevalence. Overall, only 9 of 32 studies met all five methodological soundness criteria. More well designed, executed, and reported primary research is needed at the farm and post-farm levels.

Dioxins in food chain linked to breastfeeding ills
09 Jun 2009
University of Rochester Medical Center
Exposure to dioxins during pregnancy harms the cells in rapidly-changing breast tissue, which may explain why some women have trouble breastfeeding or don't produce enough milk, according to a University of Rochester Medical Center study.
Researchers believe their findings, although only demonstrated in mice at this point, begin to address an area of health that impacts millions of women but has received little attention in the laboratory, a corresponding author was quoted as saying.
Dioxins are generated mostly by the incineration of municipal and medical waste, especially certain plastics. Most people are exposed through diet. Dioxins gets into the food supply when air emissions settle on farm fields and where livestock graze. Fish also ingest dioxins and related pollutants from contaminated waters. When humans take in dioxin – most often through meat, dairy products, fish and shellfish – the toxin settles in fatty tissues; natural elimination takes place very slowly. The typical human exposure is a daily low dose, which has been linked to possible impairment of the immune system and developing organs.
In 2004 the researchers’ laboratory made the novel discovery that dioxin impairs the normal development of mammary glands during pregnancy. However, the underlying mechanisms were unclear, as was the extent of injury and whether exposure during certain stages of pregnancy had more or less of an impact on milk production.
This week, in an online report in Toxicological Sciences, researchers showed that dioxin has a profound effect on breast tissue by causing mammary cells to stop their natural cycle of proliferation as early as six days into pregnancy, and lasting through mid-pregnancy. In tissue samples from mice, exposure to dioxin caused a 50-percent decrease in new epithelial cells.
Researchers also found that dioxin altered the induction of milk-producing genes, which occurs around the ninth day of pregnancy, and decreased the number of ductal branches and mature lobules in the mammary tissue.
The next step is to understand what controls the differentiation process. An important question to answer, the researcher said, is whether the toxic harm is occurring directly in the breast, or if it occurs throughout the entire body but has a unique manifestation in the fatty mammary tissue.
The URMC research group is also studying a possible connection between dioxin and breast cancer. Their hypothesis is that dioxin exposure in some people might cancel the general protection that pregnancy has on breast tissue against breast cancer.

Bird flu can linger in landfills
09 Jun 2009
msnbc.com [edited] [FSNet]
After an outbreak of the bird flu, most carcasses end up in landfills. There, according to a new study, the virus can survive for up to two years.
Landfills are designed to contain waste for far longer than that, so the practice is probably safe. Still, the new study suggests that waste managers might want to be particularly careful with how they dispose of infected birds.

WHO-Avian Influenza vaccine, transmission
8 Jun 2009
The Poultry Site [edited][ProMed]
A new H5N1 recombinant vaccine virus has been developed by the WHO Collaborating Center for the Surveillance, Epidemiology and Control of Influenza at the Centers for Disease Control and Prevention, thanks to the Ministry of Health & Population of Egypt for providing the virus specimens.
This recombinant vaccine virus is available for distribution, under a Material Transfer Agreement (MTA).
Institutions, companies, and others interested in pandemic vaccine development, who wish to receive these candidate vaccine viruses should contact either the WHO Global Influenza Programme(<GISN@who.int>) or the Centers for Disease Control and Prevention.
Studies on the antigenic properties of A (H5N1) vaccine viruses and their relation to the emerging H5N1 viruses are ongoing in the WHO Global Influenza Surveillance Network.
The Global Influenza Program has been closely monitoring the antigenic and genetic evolution of the circulating viruses, especially human virus isolates. Countries are encouraged to share with WHO their specimens and/or isolates, both from humans and animals, for their inclusion in the WHO H5N1 vaccine virus development and selection process, in addition to other activities of public health significance.

Acidified sodium chlorite as an alternative to chlorine for eliminatino ofSalmonella on alfalfa seeds
14 Apr 2009
Journal of Food Science, Volume 74 Issue 4, Pages M159 - M164 [edited] [FSNet]
The health and environmental hazard associated with the use of chlorine for food processing has been documented previously. This study was conducted to determine if acidified sodium chlorite (ASC) could be used to replace calcium hypochlorite (Ca[OCl]2) for disinfection of alfalfa seeds. Contaminated seeds containing approximately 1.5 × 107 CFU/g ofSalmonellawere treated with ASC or Ca(OCl)2 at different concentrations and for different periods of time. Results showed that the efficacy of ASC and Ca(OCl)2 for elimination ofSalmonellaon contaminated seeds could be improved greatly by extending the treatment time from the traditional 15 to 45 min. Treatment of seeds with 800 ppm of ASC for 45 min reduced the number ofSalmonellaby 3.9 log units, approximately 1.2 log units higher than that treated with 20000 ppm of Ca(OCl)2. Treatment of seeds with a lower concentration (100 to 400 ppm) of ASC for 45 min reduced the number ofSalmonellaby 1.3 to 2.2 log units. Soaking alfalfa seeds in 800 ppm of ASC for 45 min did not affect seed germination. However, soaking seeds in 20000 ppm of Ca(OCl)2 for 45 min reduced seed germination by 20%. Unlike Ca(OCl)2, antimicrobial efficiency of ASC was not affected by pre-exposure to alfalfa seeds. Data presented also showed thatSalmonellaon newly inoculated seeds that had been stored at 4 °C for less than 7 d were more sensitive to sanitizer treatment than those on seeds that had been stored for 4 wk or longer.

Inhibitory effect of commercial green tea and rosemary leaf powders on the growth of foodborne pathogens in laboratory media and oriental-style rice cakes
12 May 2009
Journal of Food Protection, Volume 72, Number 5, pp. 1107-1111(5) [edited] [FSNet]
The antimicrobial effects of green tea and rosemary added to foods as antagonists to foodborne pathogens were determined in laboratory media and oriental-style rice cakes. The growth of each pathogen (Bacillus cereus,SalmonellaTyphimurium,Enterobacter sakazakii,Escherichia coliO157:H7,Staphylococcus aureus, andListeria monocytogenes) in tryptic soy broth or rice cake with or without addition of green tea or rosemary leaf powders before autoclaving or cooking, respectively, was investigated after inoculation. The addition of 1% green tea or rosemary produced similar results for inhibiting the growth of pathogens in tryptic soy broth. However, green tea was more effective than rosemary for inhibiting the growth ofL. monocytogenes. Both botanicals had inhibitory effects against all pathogens tested in this study. Green tea was particularly effective againstB. cereus,S. aureus, andL. monocytogenes, and rosemary was strongly inhibitory againstB. cereusandS. aureus. The addition of 1 or 3% green tea or rosemary to rice cakes did not significantly reduce total aerobic counts; however, levels ofB. cereusandS. aureuswere significantly reduced in rice cakes stored for 3 days at room temperature (22°C). The order of antimicrobial activities againstB. cereusin rice cake was 1% rosemary < 1% green tea < 3% rosemary = 3% green tea. These results indicate that the use of natural plant materials such as green tea and rosemary could improve the microbial quality of foods in addition to their functional properties.

Prevalence ofArcobacterin meat and shellfish
12 May 2009
Journal of Food Protection, Volume 72, Number 5, pp. 1102-1106(5) [edited] [FSNet]
Arcobacteris considered an emergent foodborne and waterborne enteropathogen. However, its prevalence in foods of animal origin is only partially known, because most studies have been concentrated on poultry, pork, and beef, and methods applied do not allow identification of all currently acceptedArcobacterspecies. We investigated the prevalence ofArcobacterin 203 food samples, 119 samples of seven different types of meats and 84 samples of four types of shellfish. Isolates were identified in parallel by using a published multiplex PCR method and a recently described 16S rDNA restriction fragment length polymorphism method that allows all currently acceptedArcobacterspecies to be characterized. The global prevalence ofArcobacterwas 32%; it was highest in clams (5 of 5 samples, 100%) and chicken (9 of 14 samples, 64.3%) followed by pork (9 of 17 samples, 53.0%), mussels (23 of 56 samples, 41.1%), and duck meat (2 of 5 samples, 40.0%). Turkey meat and beef had a similar recovery rate (10 of 30 samples, 33.3%; 5 of 16 samples, 31.3%; respectively), and rabbit meat had the lowest rate (1 of 10 samples, 10.0%). No arcobacters were found in oysters, frozen shrimps, or sausages. This food survey is the first in which five of the seven acceptedArcobacterspecies have been isolated.Arcobacter butzleriwas the most prevalent species (63.0% of isolates) followed byArcobacter cryaerophilus(26.6%),Arcobactermytili(4.7%),Arcobacter skirrowii(3.1%), andArcobacter nitrofigilis(3.1%). Three (4.7%) of the isolates were classified as belonging to three potentially new phylogenetic lines. Our results indicated thatArcobacterspecies are widely distributed in the food products studied.

Antimicrobial resistance genes inEscherichia coliisolates recovered from a commercial beef processing plant
12 May 2009
Aslam, Mueen; Diarra, Moussa S.; Service, Cara; Rempel, Heidi
Journal of Food Protection, Volume 72, Number 5, pp. 1089-1093(5) [edited] [FSNet]
The goal of this study was to assess the distribution of antimicrobial resistance (AMR) genes inEscherichia coliisolates recovered from a commercial beef processing plant. A total of 123 antimicrobial-resistantE. coliisolates were used: 34 from animal hides, 10 from washed carcasses, 27 from conveyers for moving carcasses and meat, 26 from beef trimmings, and 26 from ground meat. The data suggest thatE. coliisolates harboring AMR genes are widely distributed in meat processing environments and can create a pool of transferable resistance genes for pathogens. The results of this study underscore the need for effective hygienic and sanitation procedures in meat plants to reduce the risks of contamination with antimicrobial-resistant bacteria.

Efficacy of sodium hypochlorite and peroxyacetic acid to reduce murine Norovirus 1, B40-8,Listeria monocytogenes,andEscherichia coliO157:H7 on shredded iceberg lettuce and in residual wash water
12 May 2009
Journal of Food Protection, Volume 72, Number 5, pp. 1047-1054(8) [edited] [FSNet]
The efficiency of sodium hypochlorite (NaOCl) and peroxyacetic acid (PAA) to reduce murine norovirus 1 (MNV-1), a surrogate for human norovirus, and Bacteroides fragilis HSP40-infecting phage B40-8 on shredded iceberg lettuce was investigated. The levels of removal of viruses MNV-1 and B40-8 were compared with the reductions observed for bacterial pathogensListeria monocytogenesandEscherichia coliO157:H7. Neither MNV-1, B40-8, nor bacterial pathogens could be detected in residual wash water after shredded iceberg lettuce was treated with NaOCl and PAA, whereas considerable numbers of all these microorganisms were found in residual wash water consisting solely of tap water. This study illustrates the usefulness of PAA and NaOCl in preventing cross-contamination during the washing process rather than in causing a reduction of the number of pathogens present on lettuce.

Inactivation ofSalmonellaandEscherichia coliO157:H7 on lettuce and poultry skin by combinations of levulinic acid and sodium dodecyl sulfate
12 May 2009
Journal of Food Protection, Volume 72, Number 5, pp. 928-936(9)
Zhao, Tong; Zhao, Ping; Doyle, Michael P.
Four organic acids (lactic acid, acetic acid, caprylic acid, and levulinic acid) and sodium dodecyl sulfate (SDS) were evaluated individually or in combination for their ability to inactivateSalmonellaandEscherichia coliO157:H7. Results from pure culture assays in water with the treatment chemical revealed that 0.5% organic acid and 0.05 to 1% SDS, when used individually, reduced pathogen cell numbers by =2 log CFU/ml within 20 min at 21°C. The combination of any of these organic acids at 0.5% with 0.05% SDS resulted in >7 log CFU/ml inactivation ofSalmonellaandE. coliO157:H7 within 10 s at 21°C. A combination of levulinic acid and SDS was evaluated at different concentrations for pathogen reduction on lettuce at 21°C, on poultry (wings and skin) at 8°C, and in water containing chicken feces or feathers at 21°C. Results revealed that treatment of lettuce with a combination of 3% levulinic acid plus 1% SDS for 6.7 log CFU/g on lettuce.Salmonellaand aerobic bacterial populations on chicken wings were reduced by >5 log CFU/g by treatment with 3% levulinic acid plus 2% SDS for 1 min. Treating water heavily contaminated with chicken feces with 3% levulinic acid plus 2% SDS reducedSalmonellapopulations by >7 log CFU/ml within 20 s. The use of levulinic acid plus SDS as a wash solution may have practical application for killing foodborne enteric pathogens on fresh produce and uncooked poultry.

Antimicrobial activity of catfish gelatin coating containing origanum (Thymuscapitatus) oil against gram-negative pathogenic bacteria
14 Apr 2009
Journal of Food Science, Volume 74 Issue 4, Pages M143 - M148 [edited] [FSNet]
The antimicrobial activity of origanum oil (OG) was determined againstSalmonellaTyphimurium andE. coliO157:H7. The efficacy of catfish gelatin coating containing selected concentrations of OG (0.5%, 1.0%, and 2.0%, v/v) was also investigated in catfish flesh irradiated, inoculated with both bacteria, and stored at selected temperatures. The antimicrobial activity of catfish gelatin coating was determined by cell counts during storage at 4 and 10 °C for 12 days. In the media, the inhibitory effects of OG againstS. Typhimurium were greater than the inhibition effects againstE. coliO157:H7, exhibiting complete inhibition againstS. Typhimurium at the concentration greater than 0.5% (v/v). The incorporation of OG into catfish gelatin coating also inhibited bothS. Typhimurium andE. coliO157:H7 in catfish flesh stored at 4 °C. The incorporation of OG into catfish gelatin coating exhibited greater antimicrobial activity against S. Typhimurium than against E. coli O157:H7 at both temperatures.

Early detection of disease outbreaks using the Internet
14 Apr 2009
Canadian Medical Association Journal
Kumanan Wilson, MD MSc and John S. Brownstein, PhD [edited][iFSN]
From the Department of Medicine (Wilson), Ottawa Health Research Institute, University of Ottawa, Ottawa Ont., the Children’s Hospital Informatics Program (Brownstein), Children’s Hospital Boston; and the Department of Pediatrics (Brownstein), Harvard Medical School, Boston, USA
Rapidly identifying an infectious disease outbreak is critical, both for effective initiation of public health intervention measures and timely alerting of government agencies and the general public. Surveillance capacity for such detection can be costly, and many countries lack the public health infrastructure to identify outbreaks at their earliest stages. Furthermore, there may be economic incentives for countries to not fully disclose the nature and extent of an outbreak. The Internet, however, is revolutionizing how epidemic intelligence is gathered, and it offers solutions to some of these challenges. Freely available Web-based sources of information may allow us to detect disease outbreaks earlier with reduced cost and increased reporting transparency.
Key Points:
Internet surveillance tools can assist in the early identification of disease outbreaks and raise public awareness about emerging disease threats.
Surveillance based on trends of specific terms entered into search engines offers the potential to assist in earlier detection, but this technique requires further evaluation.
Search engine queries of the term "listeriosis" demonstrated a possible signal of an outbreak before the official announcement was made in Canada.

Those 50 and older most vulnerable to food illnesses
10 Apr 2009
USA Today - Elizabeth Weise [edited][iFSN]
According to this story, scientists have found, to their surprise, that people 50 and older are the most vulnerable to illness and death from food-borne illnesses.
The Centers for Disease Control and Prevention released the 2008 findings of its FoodNet reporting system Thursday.
The story goes on by explaining that when the CDC did a more targeted analysis, it found that hospitalization and death rates are significantly higher for people 50 and older.

Internet surveillance systems for early alerting of health threats
03 Apr 2009
Eurosurveillance, Volume 14, Issue 13
J P Linge, R Steinberger, T P Weber, R Yangarber, E van der Goot, D H Al Khudhairy, N I Stilianakis
In order to gather a comprehensive picture of potential epidemic threats, public health authorities increasingly rely on systems that perform epidemic intelligence (EI). EI makes use of information that originates from official sources such as national public health surveillance systems as well as from informal sources such as electronic media and web-based information tools. All these sources are employed to enhance risk monitoring with the purpose of early alerting and initial risk assessment. In this context researchers distinguish between indicator-based risk monitoring and event-based risk monitoring. As indicator-based monitoring relies on classical routine surveillance, many systems will use methods and data sources familiar to most epidemiologists and public health officials. The event-based component of EI is in contrast rather new; its methods, strengths and limitations are generally not widely known in the public health community. The purpose of this editorial is thus to provide an overview of the methods used in pro-active event-based monitoring and to put them into context with regard to the structured indicator-based monitoring such as that described in the article on the Lithuanian electronic surveillance system published in this issue of Eurosurveillance.
More and more national and international public health agencies employ systematic event detection systems using informal sources (news wires, media sources or websites) on the internet to monitor the potential threat of emerging and re-emerging infectious diseases. Such web-based event detection is the first step in EI systems designed to provide early warning signals to public health institutions. A number of different systems have been developed for this purpose. There is, however, still the need to emphasize some fundamental differences between the available systems and to identify the challenges that lie ahead. Existing event detection systems can be classified into three categories.
First, news aggregators collect articles from several sources, usually filtered by language or country. Users gain easy access to many sources through a common portal, but still need to examine each individual article.
Second, automatic systems such as the Medical Information System (MedISys), Pattern-based Understanding and Learning System (PULS), HealthMap, and BioCaster Global Health Monitor go beyond the mere gathering task by adding a series of analysis steps. Automatic systems differ in their levels of analysis, in the range of information sources, their language coverage, the speed of delivering information and visualisation methods. HealthMap currently covers five languages, BioCaster seven languages, and MedISys more than 40 languages. While HealthMap mainly relies on Google News, World Health Organization (WHO) news feeds, ProMED-Mail, and Eurosurveillance as sources, MedISys monitors ProMED-Mail, web sites of national public health authorities, specialist web sites (including Eurosurveillance), news from about twenty news wires, plus a balanced list of approximately 2,200 news sources from around the world, hand-selected with a view of ensuring a geographic balance.
Analysis steps may include: recognition of relevant terms (names of diseases, symptoms and organizations), recognition and disambiguation of geographical locations mentioned in the articles, grouping related articles into clusters, and extraction of full events from the news, providing the users with aggregated information about the disease, the number of cases, as well as time and place of an outbreak. Ideally, news items should be clustered across languages and national borders. Most systems focus on recognizing communicable diseases and visualize the location of the extracted events on geographical maps. As a domain-specific application of the Europe Media Monitor (EMM) system, MedISys covers not only the whole range of chemical, biological, radiological and nuclear threats (CBRN), but also allows using a filter to only show outbreak-related information. MedISys additionally monitors trends and calculates alert levels per disease and per country, by comparing the number of recent news items with averages. PULS, which is integrated with MedISys, extracts event data from the English MedISys articles and produces searchable outbreak data in table format.
All automatic systems will clearly benefit from better machine-translation software so that a more diverse range of sources can be tapped. Ideally, a summary of each article should be shown in the original language together with its translation.
Third, moderated systems such as ProMED-Mail, GPHIN (Global Public Health Intelligence Network) and ARGUS rely on a group of analysts to scan available news sources. The analysts take into account information from individual web sites, aggregator sites, automatic systems, and other sources such as reports from medical practitioners and health authorities. In combination with its Rapid News Service (RNS) tool, MedISys also allows for manual moderation.
There are fundamental differences in these approaches. Non-moderated systems are able to search the web and display new articles without time delay in an unbiased manner. Moderated systems show fewer irrelevant news items (fewer false positives). However, moderator bias represents a risk (false negatives); users might have a different focus than the moderators.
For users who need to react to threats quickly and possess the man-power to entertain their own monitoring effort, automatic systems are appealing because of the detection speed. Other users might prefer to wait for human-moderated feeds.
Technical implementation of aggregators is straight-forward, but for both automatic and moderated systems, many challenges lie ahead. Redundancy is a major issue. Naturally, news agencies, online and printed news sources, national and international authorities or blogs may report the same event in different ways at various time points. This often leads to misclassification of events and overestimation of impact. Furthermore, feedback loops are created when automatic systems accept input from moderated systems (or vice versa). In any moderated approach, long-term funding or volunteer participation is necessary to maintain the analyst base.
A further challenge for the future will be to improve the transition from risk monitoring to risk assessment. Recent approaches on extracting patterns of influenza-related search terms from queries stored by Google and Yahoo showed that patterns of searches matched with official influenza surveillance data, thus indicating that search-term analysis could be a useful complementary tool to surveillance. However, although search-term analysis and event-based monitoring can provide an important signal of a potential outbreak, the data gathered is usually not detailed or reliable enough to estimate relevant epidemiological parameters of incipient outbreaks and the methods are prone to false alarms.
Lithuania’s electronic reporting system described in this issue of Eurosurveillance is an example of an indicator-based component of EI which allows the collection of structured data at country level. Such national information is typically fed into the European Surveillance System (TESSy) of the European Centre for Disease Prevention and Control (ECDC) which collects surveillance data on infectious diseases at the European Union (EU) level to support outbreak detection, risk assessment, outbreak investigation and control measures. This is complemented by the Early Warning and Response System (EWRS) which establishes permanent communication between public health authorities in the EU member states.

Canada -Web searches may have foreshadowed listeriosis crisis
12 Mar 2009
Calgary Herald - Sharon Kirkey, Canwest News Service [iFSN]
According to this story, search engine queries of the term "listeriosis" demonstrated a possible signal of the deadly outbreak that killed 20 Canadians a month before the official announcement was made in Canada, a new analysis shows. The public was officially informed by federal officials that one death and 16 cases were linked to the listeriosis outbreak on Aug. 20, 2008.
But researchers from the University of Ottawa and Harvard Medical School found peak searching for the term "listeriosis" spiked beginning in mid- to late-July, "nearly a month before the declaration of the public outbreak," the team reports in an article released Thursday by the Canadian Medical Association Journal.
The story goes on by explaining that the researchers don't know who was doing the early searchers. It could have been food inspection or industry officials investigating the possibility of the outbreak, they say, or queries by family and friends of people diagnosed early.

Normal human gut bacteria may inhibit Shiga toxin development following infection withE. coliO157:H7
04 Mar 2009
American Society for Microbiology - Carrie Slijepcevic [edited][iFSN]
A new study suggests that normal human intestinal bacteria may inhibit the development of Shiga toxin 2 (Stx2), the toxin responsible for causing the more severe symptoms associated with food-borne disease, followingEscherichia coliO157:H7 infection. The researchers from France report their findings in the February 2009 issue of the journal Infection and Immunity.
EnterohemorrhagicE. coliO157:H7 causes food-borne disease with symptoms ranging from diarrhea and hemorrhagic colitis to potentially fatal hemolytic-uremic syndrome. Stx2 is released in the gut following oral ingestion ofE. coliO157:H7 and is the main virulence factor responsible for the more serious complications from the disease. Despite what researchers already know about the role of Stx2 in the progression of the disease, how the molecules released by the normal intestinal bacteria impact Stx2 is largely unknown.
In the study Stx2 synthesis was analyzed following the growth ofE. coliO157:H7 in contents collected from the large bowel of rats colonized with normal human intestinal bacteria. Results showed that extracellular molecules, produced in part byBacteroides thetaiotaomicron(a predominant species of the normal human intestine), repressed Stx2 development.
"Our findings demonstrate for the first time the regulatory activity of a soluble factor produced by the complex human digestive microbiota on a bacterial virulence factor in a physiologically relevant context," say the researchers.

New variants of diarrhea-causing toxins found in seafood
19 Feb 2009
Norwegian School of Veterinary Science - ScienceDaily [iFSN]
Trine-Lise Torgersen described in her doctorate new variants of diarrhea-causing toxins in mussels, oysters and crabs. These variants are assumed to be less virulent than the forms of diarrhea toxin we are already familiar with and were found in varying amounts in the different types of seafood examined.
For her doctoral thesis, Trine-Lise Torgersen looked at how toxins from algae are taken up and metabolized by mussels and oysters, and also by crabs that eat mussels. During an algal bloom in the ocean, toxins produced by the algae can be taken up by shellfish that filter seawater for food, and the result for the consumer can be diarrhea, vomiting and nausea. Some of these algal toxins are already well-known.
Torgersen studied how mussels and oysters process some of these toxins, and found that more types of toxin are produced than we previously have been aware of. She also looked at how the toxins are taken up and metabolized by crabs that eat poisonous shellfish. The results indicate that a particularly complex pattern of toxins is formed in these species, and that the levels of modified diarrhea toxins may be higher than the levels of the known forms, especially in oysters and crabs.
The current procedure for measuring algal toxins involves converting all of the variants back to the original molecule, and then measuring the total amount of original toxin. However, since the modified variants of the toxins can be assumed to be less virulent than the original forms, measuring all of the substances as if they were the original may overestimate the toxicity of the seafood. Therefore, when estimating the risk of food poisoning from shellfish, levels of variants of the original toxin in the various types of seafood should be considered.
In her thesis, Torgersen showed that oysters, mussels and crabs differ regarding the forms of diarrhea toxin they contained, and also regarding how much of modified variant is present relative to the original toxin. In particular, crabs and oysters contained very little of the original substances and nearly all of the toxin had been converted to other forms. Torgersen therefore recommends that different types of seafood need to be considered individually when estimating the risks of food poisoning from seafood.

Fresh fruits and vegetables are increasingly recognized as a source of food poisoning outbreaks
13 Feb 2009
Science Daily - Cambridge University
Raw fruits and vegetables are good for you but may also send you to the doctor, according to research published today by Cambridge University Press in the journal Epidemiology and Infection.
A review article in the journal, written by several experts in their field, has highlighted the fact that fresh fruits and vegetables are increasingly recognised as a source of food poisoning outbreaks in many parts of the world.
In Europe, recent outbreaks have revealed new and unexplained links between some bacteria and viruses that cause food poisoning and imported baby corn, lettuces, and even raspberries. In the USA, recent outbreaks ofE. coliinfections have been linked to bagged baby spinach, andSalmonellato peppers, imported cantaloupe melons and tomatoes as well.
Professor Norman Noah, Editor-in-Chief of the journal says: "This research confirms that raw fruit and vegetables can cause food poisoning. To obtain raw fruit and vegetables out of season, as many countries now do, they are transported many thousands of miles from growing areas, and outbreaks can affect many widely dispersed countries simultaneously. Some outbreaks undoubtedly go unrecognized, and the scale of the problem is as yet unknown.
"Identifying the source of contamination in any outbreak requires a careful assessment of potential exposures. Further work needs to be done to fully understand where the organisms that cause the poisoning come from, and at which point in the journey from field to fork."
In the journal, the links between raw produce and food poisoning have been compared with other foods that are now well-recognized sources of infection with particular bacteria, such as eggs withSalmonellaand beef mince withE. coli.

Chagas' disease as a foodborne illness
01 Feb 2009[edited][iFSN]
Journal of Food Protection®, Volume 72, Number 2, February 2009 , pp. 441-446(6)
Pereira, Karen Signori; Schmidt, Flávio Luis; Guaraldo, Ana M.A.; Franco, Regina M.B.; Dias, Viviane L.; Passos, Luiz A.C.
Various researchers have studied the importance of the oral transmission of Chagas' disease since the mid-20th century. Only in recent years, due to an outbreak that occurred in the Brazilian State of Santa Catarina in 2005 and to various outbreaks occurring during the last 3 years in the Brazilian Amazon basin, mainly associated with the consumption of Amazonian palm berry or açaí (Euterpe oleraceaMart.) juice, has this transmission route aroused the attention of researchers. Nevertheless, reports published in the 1960s already indicated the possibility of Chagas' disease transmission via food in Brazil, mainly in the Amazonian region. Recently, in December 2007, an outbreak of Chagas' disease occurred in Caracas, Venezuela, related to ingestion of contaminated fruit juices. The objective of this article is to point out the importance of foodborne transmission in the etiology of Chagas' disease, on the basis of published research and Brazilian epidemiology data.

Outbreaks where food workers have been implicated in the spread of foodborne disease.
Transmission and survival of pathogens in the food processing and preparation environment
01 Jan 2009
Journal of Food Protection®, Volume 72, Number 1, January 2009 , pp. 202-219(18)
Todd, Ewen C.D.; Greig, Judy D.; Bartleson, Charles A.; Michaels, Barry S.
This article, the sixth in a series reviewing the role of food workers in foodborne outbreaks, describes the source and means of pathogen transfer. The transmission and survival of enteric pathogens in the food processing and preparation environment through human and raw food sources is reviewed, with the main objective of providing information critical to the reduction of illness due to foodborne outbreaks. Pathogens in the food preparation area can originate from infected food workers, raw foods, or other environmental sources. These pathogens can then spread within food preparation or processing facilities through sometimes complex pathways and may infect one or more workers or the consumer of foods processed or prepared by these infected workers. The most frequent means of worker contamination is the fecal-oral route, and study results have indicated that toilet paper may not stop transmission of pathogens to hands. However, contact with raw foods of animal origin, worker aerosols (from sneezes), vomit, and exposed hand lesions also have been associated with outbreaks. Transfer of pathogens has been documented through contaminated fabrics and carpets, rings, currency, skin surfaces, dust, and aerosols and though person-to-person transmission. Results of experiments on pathogen survival have indicated that transmission depends on the species, the inoculum delivery route, the contact surface type, the duration and temperature of exposure, and the relative humidity. Generally, viruses and encysted parasites are more resistant than enteric bacteria to adverse environmental conditions, but all pathogens can survive long enough for transfer from a contaminated worker to food, food contact surfaces, or fellow workers.

Effect of biting before dipping (double-dipping) chips on the bacterial population of the dipping solution
30 Jan 2009
Journal of Food Safety, Volume 29 Issue 1, Pages 37 - 48
JUDITH TREVINO, BRAD BALLIEU, RACHEL YOST, SAMANTHA DANNA, GENEVIEVE HARRIS, JACKLYN DEJONCKHEERE, DANIELLE DIMITROFF , MARK PHILIPS , INYEE HAN , CHLOE MOORE and PAUL DAWSON
The effect of "double-dipping" crackers/chips on the transfer of bacteria from the mouth to the dipping solution was determined in three separate experiments. In experiment 1, eight subjects dipped crackers either three or six times into sterilized water either biting or not biting before each dip. The dipping solutions had higher (P ≤ 0.05) bacterial populations when crackers were bitten before dipping compared with when no double-dipping occurred. The second experiment utilized sterile water dipping solutions with pHs of 4, 5 and 6, and tested the solutions at 0 and 2 hours after dipping. There was again significant (P ≤ 0.05) bacterial transfer due to biting then dipping; however, the pH 4 dipping solution had initially lower bacterial populations than the higher pH solutions and even lower populations after 2 hours. In the third experiment, three dipping solutions (salsa, chocolate sauce and cheese) were tested, and higher initial populations (P ≤ 0.05) were transferred to the salsa compared with chocolate and cheese; however, the salsa had lower levels of bacteria after 2 hours of hold time at room temperature. Three experiments determined that the bacterial population of food dips increased due to the practice of "double-dipping," and that dip type can influence the dip's bacterial population.

X-ray irradiation does not affect food quality, say US scientists
08 Jan 2009
Food Navigator - Jane Byrne [edited][iFSN]
X-ray technology is effective in killing bacterial pathogens in leafy greens without causing undesirable changes in product quality, claim US researchers. Bradley Marks and Sanghyup Jeong, who are both based at Michigan State University (MSU), claim that X-rays can kill bacterial pathogens such asE.coliO157:H7 andSalmonellaon the most delicate vegetables as well as extending the shelf life of the produce.

TheSalmonellaPathogenicity Island (SPI) 1 contributes more than SPI2 to the colonization of the chicken bySalmonella entericaserovar Typhimurium
06 Jan 2009
BMC Microbiology, 9:3
Yakhya Dieye, Keith Ameiss, Melha Mellata and Roy Curtiss III [edited] [iFSN]
Background
Salmonella entericaserovar Typhimurium (Typhimurium) is an important pathogen that infects a broad range of hosts. In humans, Typhimurium causes a gastroenteritis characterized by vomiting, diarrhea, and abdominal pains. Typhimurium infection occurs mainly through the ingestion of contaminated food including poultry, pork, eggs, and milk. Chickens that are asymptomatic carriers of Typhimurium constitute a potential reservoir for infection. The type three secretion systems encoded bySalmonellapathogenicity islands (SPI) 1 and 2 are major virulence factors ofSalmonella. However,only a few studies have investigated their role during the infection of chickens.
Results
We have taken a mixed infection approach to study the contribution of SPI1 and SPI2 to the colonization of the chicken by Typhimurium. We found that SPI1 contributes to colonization of both the cecum and spleen in the chicken. In contrast, SPI2 contributes to colonization of the spleen but not the cecum and, in the absence of SPI1, inhibits cecal colonization. Additionally, we show that the contribution of SPI1 in the spleen is greater than that of SPI2. These results are different from those observed during the infection of the mouse by Typhimurium where SPI2 is the major player during systemic colonization.
Conclusions
The co-infection model we used provides a sensitive assay that confirms the role of SPI1 and clarifies the role of SPI2 in the colonization of the chicken by Typhimurium.

The antioxidant capacity and polyphenol content of organic and conventional retail vegetables after domestic cooking
01 Jan 2009
Food Research International, Volume 42, Issue 1, Pages 210-215
A.L.K. Faller and E. Fialho
Vegetable consumption is associated with health benefits. Organic foods are thought to have higher contents of antioxidant substances. The objective of this work is to quantify soluble and hydrolyzable polyphenols, ascorbic acid, and the antioxidant capacity of fresh conventional and organic retail vegetables (potato, carrot, onion, broccoli, and white cabbage) while evaluating the effect of boiling, microwaving, and steaming on these parameters. The recovery rate for soluble and hydrolyzable polyphenols was variable according to the vegetable analyzed. However, soluble polyphenols resulted in lower recovery rates than did hydrolyzable phenolics after cooking. Organic vegetables showed higher sensitivity to heat processing than did conventionally grown vegetables. In general, cooking was found to lead to reductions in the antioxidant capacity for most vegetables, with small differences between the cooking methods applied. Even with the alterations in their content, polyphenols showed a positive correlation with antioxidant capacity in raw and cooked vegetables from both types of agriculture.

Food processing a tool to pesticide residue dissipation
01 Jan 2009
Food Research International, Volume 42, Issue 1, Pages 26-40
Geetanjali Kaushik, Santosh Satya and S.N. Naik [edited] [iFSN]ScienceDirect.com
Food safety is an area of growing worldwide concern on account of its direct bearing on human health. The presence of harmful pesticide residues in food has caused a great concern among the consumers. Hence, world over to tackle food safety issues, organic farming is being propagated. However, due to several reasons, diffusion and acceptance of this approach in developing countries has been very slow. Therefore, it is important in the transient phase that some pragmatic solution should be developed to tackle this situation of food safety. Food processing treatments such as washing, peeling, canning or cooking lead to a significant reduction of pesticide residues. In this background this paper reviews the common food processing operations along with the degree of residue removal in each process. The processes reviewed include: baking, bread making, dairy product manufacture, drying, thermal processing, fermentation, freezing, infusion, juicing, malting, milling, parboiling, peeling, peeling and cooking, storage, storage and milling, washing, washing and cooking, washing and drying, washing and peeling, washing peeling and juicing and wine making. Extensive literature review demonstrates that in most cases processing leads to large reductions in residue levels in the prepared food, particularly through washing, peeling and cooking operations.

Outbreaks where food workers have been implicated in the spread of foodborne disease.
Transmission and survival of pathogens in the food processing and preparation environment
01 Jan 2009
Journal of Food Protection®, Volume 72, Number 1, January 2009 , pp. 202-219(18)
Todd, Ewen C.D.; Greig, Judy D.; Bartleson, Charles A.; Michaels, Barry S.
This article, the sixth in a series reviewing the role of food workers in foodborne outbreaks, describes the source and means of pathogen transfer. The transmission and survival of enteric pathogens in the food processing and preparation environment through human and raw food sources is reviewed, with the main objective of providing information critical to the reduction of illness due to foodborne outbreaks. Pathogens in the food preparation area can originate from infected food workers, raw foods, or other environmental sources. These pathogens can then spread within food preparation or processing facilities through sometimes complex pathways and may infect one or more workers or the consumer of foods processed or prepared by these infected workers. The most frequent means of worker contamination is the fecal-oral route, and study results have indicated that toilet paper may not stop transmission of pathogens to hands. However, contact with raw foods of animal origin, worker aerosols (from sneezes), vomit, and exposed hand lesions also have been associated with outbreaks. Transfer of pathogens has been documented through contaminated fabrics and carpets, rings, currency, skin surfaces, dust, and aerosols and though person-to-person transmission. Results of experiments on pathogen survival have indicated that transmission depends on the species, the inoculum delivery route, the contact surface type, the duration and temperature of exposure, and the relative humidity. Generally, viruses and encysted parasites are more resistant than enteric bacteria to adverse environmental conditions, but all pathogens can survive long enough for transfer from a contaminated worker to food, food contact surfaces, or fellow workers.
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