Changes

Key:  Additions   Deletions
01 Jun 2010
Journal of Food Protection®, Volume 73, Number 6, pp. 1141-1152(12) [edited][FSNet]
Campylobacter is a commensal in poultry, and therefore, poultry and poultry products are major sources of Campylobacter infections in humans. Fluoroquinolones inhibit the growth of Campylobacter and other microorganisms by binding to bacterial DNA gyrase and DNA topoisomerase IV. These enzymes are associated with bacterial transcription, replication, and chromosome condensation and segregation. Selection pressure in the presence of fluoroquinolones rapidly leads to resistance in Campylobacter, due to the selection for mutations in DNA gyrase. Fluoroquinolone-resistant campylobacters have been found in poultry feces and carcasses, and in retail poultry meat products in most areas of the world. In addition, other food animals and the meat products from those animals have been shown contaminated with fluoroquinolone-resistant campylobacters. Even the removal of fluoroquinolones from use in treating animal diseases has not entirely eliminated the presence of resistant Campylobacter jejuni and Campylobacter coli from animals and animal products. Human exposure to Campylobacter infection could be reduced by using strategies that decrease colonization of chickens by the pathogen.

01 Jun 2010
Journal of Food Protection®, Volume 73, Number 6, pp. 1023-1029(7)
[edited][FSNet]
Numerous field studies have revealed that irrigation water can contaminate the surface of plants; however, the occurrence of pathogen internalization is unclear. This study was conducted to determine the sites of Escherichia coli O157:H7 contamination and its survival when the bacteria were applied through spray irrigation water to either field-grown spinach or lettuce. To differentiate internalized and surface populations, leaves were treated with a surface disinfectant wash before the tissue was ground for analysis of E. coli O157:H7 by direct plate count or enrichment culture. Irrigation water containing E. coli O157:H7 at 102, 104, or 106 CFU/ml was applied to spinach 48 and 69 days after transplantation of seedlings into fields. E. coli O157:H7 was initially detected after application on the surface of plants dosed at 104 CFU/ml (4 of 20 samples) and both on the surface (17 of 20 samples) and internally (5 of 20 samples) of plants dosed at 106 CFU/ml. Seven days postspraying, all spinach leaves tested negative for surface or internal contamination. In a subsequent study, irrigation water containing E. coli O157:H7 at 108 CFU/ml was sprayed onto either the abaxial (lower) or adaxial (upper) side of leaves of field-grown lettuce under sunny or shaded conditions. E. coli O157:H7 was detectable on the leaf surface 27 days postspraying, but survival was higher on leaves sprayed on the abaxial side than on leaves sprayed on the adaxial side. Internalization of E. coli O157:H7 into lettuce leaves also occurred with greater persistence in leaves sprayed on the abaxial side (up to 14 days) than in leaves sprayed on the adaxial side (2 days).

28 May 2010
BMC Microbiology 2010, 10:155 [edited][FSNet]
Vibrio choleraegains natural competence upon growth on chitin. This allows the organism to take up free DNA from the environment and to incorporate it into its genome by homologous recombination.
Making use of this developmental program in order to use it as a tool to genetically manipulateV. choleraeand potentially also othersVibriospecies was envisaged. Therefore, researchers re-investigated the experimental design for natural transformation ofV. choleraeand tested different donor DNA fragments with respect to their source (genomic versus PCR-derived), quantity, and homologous flanking regions. Furthermore, researchers simplified the procedure in terms of the chitin source used as inducer of natural competence and the composition of the growth medium.
Researchers of the current study recommend a standard protocol to genetically manipulateV. choleraeusing commercially available sources of chitin and minimal medium, respectively, as well as PCR-derived donor DNA as transforming material.

26 May 2010
Epidemiology [edited][FSNet]
Secondary transmission after point-source outbreaks is an integral feature of the epidemiology of gastrointestinal pathogens such as norovirus. The household is an important site of these secondary cases. It can become the source of further community transmission as well as new point-source outbreaks. Consequently, time-series data from exposed households provide information for risk assessment and intervention.
Maximum likelihood techniques such as these can be used to estimate transmission parameters under conditions of unobserved states and missing household size data, and to aid in the understanding of secondary risks associated with point-source outbreaks.


15 May 2010
International Journal of Hospitality Management
Ungku Zainal Abidina Ungku Fatimaha, Huey Chern Booa et al. [edited][FSNet]
Food safety is important to today's food industry operators as consumers have become increasingly concerned about risks related to food. Unlike foodservice operators or health
inspectors, consumers can only rely on the visible cues, particularly those associated with food hygiene to judge the level of food safety in eating establishments. The researchers aimed to bridge the gap by exploring the topic from the consumer perspective. Results indicate that foodservice hygiene is one of the top three considerations when consumers select a dining place. Results of confirmatory factor analysis reveal a four-factor model encompasses staff and handling, food and location, premise and practices, and scent aspects.

13 Apr 2010
Poultry Science, 89, 1070-1084
M. T. Guerin, C. Sir, J. M. Sargeant, L. Waddell et al. [edited][FSNet]
A systematic review was conducted to evaluate the change in prevalence ofCampylobacteron chicken carcasses during processing. A structured literature search of 8 electronic databases using the key words for "Campylobacter," "chicken," and "processing" identified 1,734 unique citations. Abstracts were screened for relevance by two independent reviewers. Thirty-two studies described prevalence at more than one stage during processing and were included in this review. Of the studies that described the prevalence ofCampylobacteron carcasses before and after specific stages of processing, the chilling stage had the greatest number of studies (9), followed by washing (6), defeathering (4), scalding (2), and evisceration (1). Studies that sampled before and after scalding or chilling, or both, showed that the prevalence ofCampylobactergenerally decreased immediately after the stage (scalding: 20.0 to 40.0% decrease; chilling: 100.0% decrease to 26.6% increase). The prevalence of Campylobacter increased after defeathering (10.0 to 72.0%) and evisceration (15.0%). The prevalence after washing was inconsistent among studies (23.0% decrease to 13.3% increase). Eleven studies reported the concentration of Campylobacter, as well as, or instead of, the prevalence. Studies that sampled before and after specific stages of processing showed that the concentration of Campylobacter decreased after scalding, evisceration, washing, and chilling and increased after defeathering. This understanding should help researchers and program developers identify the most likely points in processing to implement effective control efforts. For example, if contamination will occur during defeathering and likely during evisceration, critical control points postevisceration are likely to have a greater effect on the end product going to the consumer.

History and future of food irradiation
10 Apr 2010
Trends in Food Science & Technology [edited][FSNet]
Treatment of food by specific ionizing radiations to improve microbiological safety and storability is one of the most extensively studied technology of the century. However, much of the research has been carried out in laboratories and it is still relatively underutilized commercially. Its application potential is very diverse, from inhibition of sprouting of tubers and bulbs to production of commercially sterile food products. The safety of consumption and wholesomeness of irradiated food have been extensively studied in international cooperations. Numerous international expert groups set up jointly by the FAO, the IAEA and the WHO, or the Scientific Committee on Food of the European Commission concluded that foods irradiated with appropriate technologies are both safe and nutritionally adequate. A Codex General Standard for Irradiated Foods and a Recommended International Code of Practice for Radiation Processing of Food have been developed. Specific applications of food irradiation are approved by national legislations in over 55 countries worldwide. Commercial use of irradiation, however, is still limited. In spite of pioneering past RΔactivities in Europe and North-America, the utilization of the process growing faster and increasingly, mainly for sanitary purposes, in fast-developing countries in the (South-East) Asian region and some Latin-American countries. Progress in the European Union is decidedly slower. In the EU, food irradiation is regulated since 1999 by a General Directive, but its implementing directive, the Community-list of EU-approved irradiated foods contains only a single class of items: ”dried aromatic herbs, spices and vegetable seasonings”. This slow progress is mainly due to psychological and political factors, misinformation created by various activist groups, and the reluctance to implement the process by the industry is discouraged by such forces. The future of food irradiation will depend on an informed public and better understanding of the role the process can play in the control of food-borne pathogens.



A model for setting performance objectives for Salmonella in the broiler supply chain
08 Apr 2010
Risk Analysis [edited][FSNet]
A stochastic model for setting performance objectives for Salmonella in the broiler supply chain was developed. The goal of this study was to develop a model by which performance objectives for Salmonella prevalence at various points in the production chain can be determined, based on a preset final performance objective at the end of the processing line. The transmission of Salmonella through the broiler production chain was modeled. The prevalence at flock level was calculated from the measured prevalence at sample level. The transmission model is based on data on the occurrence of Salmonella collected in the Dutch broiler production chain during several years. The developed model can be used by policymakers and industry to determine economically and politically acceptable performance objectives for various points of the production chain and to draw conclusions about which interventions are most appropriate.

The effects of risk-reducing strategies on consumer perceived risk and on purchase likelihood: a modelling approach
21 Mar 2010
British Food Journal, Volume 112, Issue 3, Pages 306 – 322 [edited][FSNet]
Ruth Yeung, Wallace Yee, Joe Morris
Consumer perception of risk and its impacts on purchasing behaviour are critical aspects of food safety. Consumer risk management strategies influence, and respond to, the risk management strategies adopted by the food industry. This research, using poultry product as the focus, aimed to identify the consumer risk-reducing strategies and their impact on perception of food safety-related risk and then on purchase behaviour.
The research reveals brand, information and quality assurance as influential risk-reducing strategies to reduce consumer perception of food safety risk and subsequently to facilitate purchase likelihood during a period concerned about microbiological contamination in chicken meat.
The results provide guidance of both proactive and remedial actions that the food industry can follow and also help to evaluate the effectiveness of its marketing activities.

Pathogenic microorganism survival in dulce de leche
13 Mar 2010
Food Control [edited][FSNet]
Denise Hentges, Daiani Teixeira da Silva, Priscila Alves Dias, et al.
In order to evaluate the survival of Salmonella Typhimurium, L. monocytogenes, E. coli O157:H7 and S. aureus in dulce de leche, aliquots of this sweet were experimentally contaminated with these pathogenic microorganisms at 103 (C1) and 101 (C2) bacterial cells per g, and later analysed to evaluate microorganism viability after storage for 0, 1, 2, 3, 5, 10, 20 and 30 days. Salmonella and L. monocytogenes were recovered from all aliquots. E. coli O157:H7 and S. aureus were recovered from all aliquots at C1 concentration, and up to the 5th and 10th day, respectively, at C2 concentration. Relevant public-health danger pathogenic microorganisms were found to survive up to 30 days in dulce de leche.

Global sensitivity analysis applied to a contamination assessment model of Listeria monocytogenes in cold smoked salmon at consumption
13 Mar 2010
Risk Analysis [edited][FSNet]
Mariem Ellouze, Jean-Pierre Gauchi, and Jean-Christophe Augustin
In this study, a variance-based global sensitivity analysis method was first applied to a contamination assessment model of Listeria monocytogenes in cold smoked vacuum packed salmon at consumption. The impact of the choice of the modeling approach (populational or cellular) of the primary and secondary models as well as the effect of their associated input factors on the final contamination level was investigated. Results provided a subset of important factors, including the food water activity, its storage temperature, and duration in the domestic refrigerator. A refined sensitivity analysis was then performed to rank the important factors, tested over narrower ranges of variation corresponding to their current distributions, using three techniques: ANOVA, Spearman correlation coefficient, and partial least squares regression. Finally, the refined sensitivity analysis was used to rank the important factors.

Reduction of Campylobacter jejuni and Campylobacter coli in poultry skin by fruit extracts
03 Mar 2010
Journal of Food Protection®, Volume 73, Number 3, pp. 477-482(6) [edited][FSNet]
Campylobacter spp. are a major cause of foodborne bacterial gastroenteritis in humans, and current methods to control Campylobacter contamination in foods are not completely successful. Plants are a promising source of antimicrobial agents, particularly given the growing interest in “all natural” foods. In this study, the antimicrobial activity of extracts from 28 edible plants against Campylobacter jejuni and Campylobacter coli was evaluated in vitro and in a poultry skin model. Nine of 28 extracts exhibited antimicrobial activity in a diffusion assay, and MBCs were determined for the three most active extracts, i.e., lime, plum, and sour orange peel (MBCs of 2 to 3 mg/ml). Mixtures of the lime, plum, and sour orange peel extracts were applied to chicken skin inoculated with 105 CFU of Campylobacter to test for synergistic or antagonist effects. After incubation (48 h at 4°C) with any extract mixture, no Campylobacter CFUs were detectable. These active extracts from edible fruits are simple to prepare and are alternatives to reduce or eliminate Campylobacter contamination of chicken products.


Survival characteristics of Cronobacter spp. in model bovine gut and in the environment
08 Feb 2010
Foodborne Pathogens and Disease. doi:10.1089/fpd.2009.0449 [edited][FSNet]
Catherine Molloy, Claire Cagney, Séamus Fanning, Geraldine Duffy
Cronobacter spp. (formally Enterobacter sakazakii) have been linked to illness in infants from contaminated powdered infant formula. The source of the pathogen remains unclear, and it is believed that farm environments and cattle could play a role in the transmission of Cronobacter spp. The aim of this study was to establish if the organism would survive passage through a model of the bovine rumen and abomasum and in bovine feces in the farm environment. Models of the bovine abomasum and rumen were inoculated with Cronobacter strains, and survival was examined over time in these environments. Fecal samples were inoculated with Cronobacter , and survival on soil and in containers stored outdoors was examined over time. The results showed no significant changes in the number of Cronobacter in rumen fluid over a 24-h period. Cronobacter were undetectable after 30 min of incubation in the model abomasum. The pathogen survived 105 days in sealed containers and was detectable after 112 days in soil. This study indicated that Cronobacter spp. are unlikely to be shed in bovine feces as supported by previous surveillance studies; however, the study did show that the organism survives well in the farm environment.

02 Feb 2010
Food Control [edited][FSNet]
Although cooking with wine and consumption of wine as a warm beverage is widespread, antibacterial effects of thermally treated wine have not been studied. Researchers examined in vitro antibacterial activity of wine heated at 75 and 125°C for 45 min against Salmonella enterica serovar Enteritidis and Escherichia coli. Their effects were compared with intact red wine, dealcoholized wine (DW) and dealcoholized wine reconstituted (RDW) with water to the initial volume. Samples were also analysed for their phenolics content, antioxidant capacity, resveratrol and ethanol content and pH. Total phenolics concentration and related antioxidative activity followed changes in samples volume, regardless of treatment type, while pH of all samples remained stable and ranged from 3.09-3.24. The order of the antibacterial activity of wine samples was: intact wine > heated at 75°C > heated at 125°C > DW > RDW. Antibacterial activity of the samples could not be related to their content of resveratrol as a single phenolics compound, antioxidative capacity or pH. Thermally treated wine under conditions applicable to food processing in everyday life, may be effective antibacterials in spite of significant heat-induced changes in their physical-chemical composition.

International Journal of Food Microbiology [edited][FSNet]
Diane G. Newell, Marion Koopmans, Linda Verhoef et al.
The burden of diseases caused by food-borne pathogens remains largely unknown. Importantly data indicating trends in food-borne infectious intestinal disease is limited to a few industrialised countries, and even fewer pathogens. It has been predicted that the importance of diarrhoeal disease, mainly due to contaminated food and water, as a cause of death will decline worldwide. Evidence for such a downward trend is limited. This prediction presumes that improvements in the production and retail of microbiologically safe food will be sustained in the developed world and moreover, will be rolled out to those countries of the developing world increasingly producing food for a global market. In this review, researchers present evidence to indicate that the microbiological safety of food remains a dynamic situation heavily influenced by multiple factors along the food chain from farm to fork. Sustaining food safety standards will depend on constant vigilance maintained by monitoring and surveillance but, with the rising importance of other food-related issues, such as food security, obesity and climate change, competition for resources in the future to enable this may be fierce. In addition the pathogen populations relevant to food safety are not static. Food is an excellent vehicle by which many pathogens (bacterial, viruses/prions and parasites) can reach an appropriate colonisation site in a new host. Although food production practices change, the well-recognised food-borne pathogens, such as Salmonella spp and E. coli, seem able to evolve to exploit novel opportunities, for example fresh produce, and even generate new public health challenges, for example antimicrobial resistance. In addition, previously unknown food-borne pathogens, many of which are zoonotic, are constantly emerging. Current understanding of the trends in food-borne diseases for bacterial, viral and parasitic pathogens has been reviewed. The bacterial pathogens are exemplified by those well-recognized by policy makers; i.e. Salmonella, Campylobacter, Escherichia coli and Listeria monocytogenes. Antimicrobial resistance in several bacterial food-borne pathogens (Salmonella, Campylobacter, Shigella and Vibrio spp, methicillin resistant Staphylcoccus aureas, E. coli and Enterococci) has been discussed as a separate topic because of its relative importance to policy issues. Awareness and surveillance of viral food-borne pathogens is generally poor but emphasis is placed on Norovirus, Hepatitis A, rotaviruses and newly emerging viruses such as SARS. Many food-borne parasitic pathogens are known (for example Ascaris, Cryptosporidia and Trichinella) but few of these are effectively monitored in foods, livestock and wildlife and their epidemiology through the food-chain is poorly understood. It is clear that one overall challenge is the generation and maintenance of constructive dialogue and collaboration between public health, veterinary and food safety experts, bringing together multidisciplinary skills and multi-pathogen expertise. Such collaboration is essential to monitor changing trends in the well-recognised diseases and detect emerging pathogens. It will also be necessary understand the multiple interactions these pathogens have with their environments during transmission along the food chain in order to develop effective prevention and control strategies.
14 Jan 2010
Food Standards Agency [edited][FSNet]
Powdered infant formula (PIF) is a generic term used to cover a range of breast milk fortifiers and substitutes. These are not manufactured as sterile products, but are intended to conform to appropriate microbiological specifications. For PIF in international trade these were recently revised by Codex Alimentarius Commission (CAC 2008). Previous FAO/WHO 2004 and 2006 expert meetings on the microbiological risk assessment of powdered infant formulas have recommended the reconstitution of PIF with water no less than 70°C, and used within 2 hours. The use of high reconstitution temperature is considered to reduce the viable count of Cronobacter spp. and Salmonella serovars and a short storage period would limit the growth of any survivors, and therefore this practice would reduce the risk of neonatal infection through the ingestion of contaminated infant formula. However it is apparent that various preparation practices are used by caregivers. This report considers the risk associated with bacterial survival and subsequent multiplication following reconstitution.