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 of Salmonella Enteritidis 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, and Escherichia coli O157: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. Campylobacter spp., Escherichia coli including Shiga toxin–producing strains, Salmonella spp., 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 of Salmonella 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 of Salmonella were 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 of Salmonella on 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 of Salmonella by 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 of Salmonella by 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 that Salmonella on 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, Salmonella Typhimurium, Enterobacter sakazakii, Escherichia coli O157:H7, Staphylococcus aureus, and Listeria 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 of L. monocytogenes. Both botanicals had inhibitory effects against all pathogens tested in this study. Green tea was particularly effective against B. cereus, S. aureus, and L. monocytogenes, and rosemary was strongly inhibitory against B. cereus and S. aureus. The addition of 1 or 3% green tea or rosemary to rice cakes did not significantly reduce total aerobic counts; however, levels of B. cereus and S. aureus were significantly reduced in rice cakes stored for 3 days at room temperature (22°C). The order of antimicrobial activities against B. cereus in 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 of Arcobacter in meat and shellfish
12 May 2009
Journal of Food Protection, Volume 72, Number 5, pp. 1102-1106(5) [edited] [FSNet]
Arcobacter is 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 accepted Arcobacter species. We investigated the prevalence of Arcobacter in 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 accepted Arcobacter species to be characterized. The global prevalence of Arcobacter was 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 accepted Arcobacter species have been isolated. Arcobacter butzleri was the most prevalent species (63.0% of isolates) followed by Arcobacter cryaerophilus (26.6%), Arcobacter mytili (4.7%), Arcobacter skirrowii (3.1%), and Arcobacter nitrofigilis (3.1%). Three (4.7%) of the isolates were classified as belonging to three potentially new phylogenetic lines. Our results indicated that Arcobacter species are widely distributed in the food products studied.

Antimicrobial resistance genes in Escherichia coli isolates 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 in Escherichia coli isolates recovered from a commercial beef processing plant. A total of 123 antimicrobial-resistant E. coli isolates 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 that E. coli isolates 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, and Escherichia coli O157: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 pathogens Listeria monocytogenes and Escherichia coli O157: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 of Salmonella and Escherichia coli O157: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 inactivate Salmonella and Escherichia coli O157: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 of Salmonella and E. coli O157: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. Salmonella and 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 reduced Salmonella populations 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 (Thymus capitatus) 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 against Salmonella Typhimurium and E. coli O157: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 against S. Typhimurium were greater than the inhibition effects against E. coli O157:H7, exhibiting complete inhibition against S. Typhimurium at the concentration greater than 0.5% (v/v). The incorporation of OG into catfish gelatin coating also inhibited both S. Typhimurium and E. coli O157: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.

Australia - Raw egg warning as Salmonella rate increases
09 Apr 2009
ABC News [edited][iFSN]
New South Wales authorities are urging people to be careful using raw eggs after a large increase in Salmonella infections.
New South Wales Health says cases of salmonellosis are up 37 percent when compared with the same period last year.
The chief health officer for New South Wales Health, Dr. Kerry Chant, says many of the infections have been linked to food containing raw eggs.
"Eggs are an animal product and the surface of the egg can be contaminated with bacteria," she said.
"It's important when you are making products associated with raw eggs that you use good food handling practices, particularly ensuring that there's good temperature control that products are kept either very hot or they're put in the refrigerator to keep refrigerated."

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 with E. coli O157: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, following Escherichia coli O157:H7 infection. The researchers from France report their findings in the February 2009 issue of the journal Infection and Immunity.
Enterohemorrhagic E. coli O157: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 of E. coli O157: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 of E. coli O157:H7 in contents collected from the large bowel of rats colonized with normal human intestinal bacteria. Results showed that extracellular molecules, produced in part by Bacteroides 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 of E. coli infections have been linked to bagged baby spinach, and Salmonella to 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 with Salmonella and beef mince with E. 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 oleracea Mart.) 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.

Research study to shed light on emerging seaborne pathogen
20 Jan 2009
University of Delaware [iFSN]
A new research study at the University of Delaware seeks to determine why Vibrio parahaemolyticus, a microorganism that lives in seawater and is related to the bacterium that causes cholera, is expanding its range and virulence.
Vibrio parahaemolyticus is a leading cause of seafood-borne illness worldwide, most frequently associated with the consumption of raw or undercooked seafood, particularly oysters and other mollusks, and crabs. Victims typically suffer from diarrhea, vomiting, fever and chills for a few days, although the infection can be fatal in those with weakened immune systems.
“This organism has been around for a long time,” says Michelle Parent, assistant professor of medical technology at the University of Delaware and a co-investigator on the study. “However, only recently, in the past decade, has a new, more virulent isolate become more prevalent around the globe.”
In North America, Vibrio parahaemolyticus is considered an “emerging pathogen.” An estimated 4,500 cases of infection occur each year in the United States, according to the Centers for Disease Control. However, the agency suggests the number likely is much higher because labs rarely use the medium necessary to identify the organism, and cases go unreported.
“Vibrio parahaemolyticus usually causes a gastrointestinal infection that lasts two to three days, although individuals with compromised immune systems who work around seawater and get infected from a cut or open wound can die within a day,” Parent says.
“This organism grows super-fast,” Parent explains. “It has a replication time of six to nine minutes, which is very quick compared to other microbes.”
The ultimate aim of the University of Delaware study is to identify this emerging pathogen's virulence genes and determine how the organism overcomes its victim's immune system -- information that can then be used to combat, detect and prevent infection.
The aquaculture industry loses millions of dollars each year due to the contamination of oyster beds with V. parahaemolyticus during the summer months. Thus, providing oyster farmers with an agent to treat the oysters is an important overall goal and potential future direction of the research, Parent says.
“Vibrio parahaemolyticus is most prevalent in the warmer summer months, especially in the U.S. Gulf Coast region where it occurs in high numbers,” collaborator E. Fidelma Boyd, an assistant professor of biological sciences at the University of Delaware, says.
“In the past decade, the organism's geographic distribution has been extended into more northerly climes, in particular, the Pacific Northwest, most likely due to global warming. Thus, the occurrence and prevalence of the organism is likely to continue to expand,” Boyd notes.
An oyster filters its food from the seawater in which it lives, ingesting not only tiny plankton but whatever else may be present in the water, including harmful bacteria such as V. parahaemolyticus. Thus, when a person consumes a raw oyster contaminated with the organism, they become infected. (Thoroughly cooking the seafood can prevent infection.)
The researchers want to determine what happens once V. parahaemolyticus attaches to a host's cells and begins multiplying.
Through a series of experiments using various infectious doses of the organism, the scientists will explore what happens when a cell is infected, and what immune response is required to eliminate infection.

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 as E. coli O157:H7 and Salmonella on the most delicate vegetables as well as extending the shelf life of the produce.

The Salmonella Pathogenicity Island (SPI) 1 contributes more than SPI2 to the colonization of the chicken by Salmonella enterica serovar Typhimurium
06 Jan 2009
BMC Microbiology, 9:3
Yakhya Dieye, Keith Ameiss, Melha Mellata and Roy Curtiss III [edited] [iFSN]
Background
Salmonella enterica serovar 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 by Salmonella pathogenicity islands (SPI) 1 and 2 are major virulence factors of Salmonella. 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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