Tag Archives: research

Research – Pathogen Tracking Data Base – Clostridium perfringens spores

Science Direct

Investigation of foodborne diseases requires the capture and analysis of time-sensitive information on microbial pathogens that is derived from multiple analytical methods and sources. The web-based Pathogen-annotated Tracking Resource Network (PATRN) system (www.patrn.net) was developed to address the data aggregation, analysis, and communication needs important to the global food safety community for the investigation of foodborne disease. PATRN incorporates a standard vocabulary for describing isolate metadata and provides a representational schema for a prototypic data exchange standard using a novel data loading wizard for aggregation of assay and attribution information. PATRN currently houses expert-curated, high-quality “foundational datasets” consisting of published experimental results from conventional assays and next generation analysis platforms for isolates of Escherichia coli, Listeria monocytogenes, and Salmonella, Shigella, Vibrio and Cronobacter species. A suite of computational tools for data mining, clustering, and graphical representation is available. Within PATRN, the public curated data repository is complemented by a secure private workspace for user-driven analyses, and for sharing data among collaborators. To demonstrate the data curation, loading wizard features, and analytical capabilities of PATRN, three use-case scenarios are presented. Use-case scenario one is a comparison of the distribution and prevalence of plasmid-encoded virulence factor genes among 249 Cronobacter strains with similar attributes to that of nine Cronobacter isolates from recent cases obtained between March and October, 2010–2011. To highlight PATRN’s data management and trend finding tools, analysis of datasets, stored in PATRN as part of an ongoing surveillance project to identify the predominant molecular serogroups among Cronobacter sakazakii isolates observed in the USA is shown. Use-case scenario two demonstrates the secure workspace available for private users to upload and analyze sensitive data, and for collating cross-platform datasets to identify and validate congruent datapoints. SNP datasets from WGS assemblies and pan-genome microarrays are analyzed in a combinatorial fashion to determine relatedness of 33 Salmonella enterica strains to six strains collected as part of an outbreak investigation. Use-case scenario three utilizes published surveillance results that describe the incidence and sources of O157:H7 E. coli isolates associated with a produce pre-harvest surveillance study that occurred during 2002–2006. In summary, PATRN is a web-based integrated platform containing tools for the management, analysis and visualization of data about foodborne pathogens.

Science Direct

The contamination of enterotoxigenic Clostridium perfringens spores on food contact surfaces posses a serious concern to food industry due to their high resistance to various preservation methods typically applied to control foodborne pathogens. In this study, we aimed to develop an strategy to inactivate C. perfringens spores on stainless steel (SS) surfaces by inducing spore germination and killing of germinated spores with commonly used disinfectants. The mixture of l-Asparagine and KCl (AK) induced maximum spore germination for all tested C. perfringens food poisoning (FP) and non-foodborne (NFB) isolates. Incubation temperature had a major impact on C. perfringens spore germination, with 40 °C induced higher germination than room temperature (RT) (20 ± 2 °C). In spore suspension, the implementation of AK-induced germination step prior to treatment with disinfectants significantly (p < 0.05) enhanced the inactivation of spores of FP strain SM101. However, under similar conditions, no significant spore inactivation was observed with NFB strain NB16. Interestingly, while the spores of FP isolates were able to germinate with AK upon their adhesion to SS chips, no significant germination was observed with spores of NFB isolates. Consequently, the incorporation of AK-induced germination step prior to decontamination of SS chips with disinfectants significantly (p < 0.05) inactivated the spores of FP isolates. Collectively, our current results showed that triggering spore germination considerably increased sporicidal activity of the commonly used disinfectants against C. perfringens FP spores attached to SS chips. These findings should help in developing an effective strategy to inactivate C. perfringens spores adhered to food contact surfaces.

 

Research – Norovirus Shedding

Cambridge Journals OnlineNorovirus

Norovirus is a common cause of gastroenteritis in all ages. Typical infections cause viral shedding periods of days to weeks, but some individuals can shed for months or years. Most norovirus risk models do not include these long-shedding individuals, and may therefore underestimate risk. We reviewed the literature for norovirus-shedding duration data and stratified these data into two distributions: regular shedding (mean 14–16 days) and long shedding (mean 105–136 days). These distributions were used to inform a norovirus transmission model that predicts the impact of long shedders. Our transmission model predicts that this subpopulation increases the outbreak potential (measured by the reproductive number) by 50–80%, the probability of an outbreak by 33%, the severity of transmission (measured by the attack rate) by 20%, and transmission duration by 100%. Characterizing and understanding shedding duration heterogeneity can provide insights into community transmission that can be useful in mitigating norovirus risk.

Play the Game – CDC iPAD Outbreak Detective

CDC iPad-STO-sm

Scientists and gamers alike can now play disease detective,  through “Solve the Outbreak,” a new iPad app from the Centers for Disease  Control and Prevention. The app lets users assume the role of a disease  outbreak investigator in the agency’s Epidemic Intelligence Service (EIS) by  navigating three fictional outbreaks based on real-life events. Users get  clues, review data, and make decisions to determine the cause of the outbreak.

“The goal is to use new technology to  provide an  engaging, interactive way for users to learn how CDC solves outbreaks, thereby  increasing general knowledge about real-life public health issues,” said CDC  Director Dr. Tom Frieden. “This application allows us to illustrate the  challenges of solving outbreaks and how our disease detectives work on the  front lines to save lives and protect people 24/7.”

In the game, participants also become familiar with health  tips, definitions and information about epidemiology, which is a science used to investigate outbreaks and to  monitor patterns, causes and effects of diseases on the public. Users  advance in rank as they earn points and can post their results on Facebook and  Twitter to challenge other participants.

“This is a great learning tool for science teachers, teens,  young adults, public health enthusiasts and mystery lovers,” said Carol  Crawford, branch chief, CDC’s Electronic Media Branch.  “The three  introductory scenarios are based on actual events EIS officers have  solved.  We also plan to add new outbreak cases.”

Research – The Microbiological Efficacy of Fresh Produce

Science Direct

Abstract

Fresh fruits and vegetables are an essential part of the world populations’ diet, contributing essential vitamins and minerals, and they are often eaten raw or minimally processed. Fruits and vegetables grown using conventional agricultural methods are at risk from microbiological contamination and foodborne illness relating to the consumption of produce is widely reported throughout the world, as illustrated by recent figures from the USA (at least 713 produce related outbreaks between 1990 and 2005) and UK (88 outbreaks between 1996 and 2006). Better understanding of produce decontamination is essential to support industry in assuring the safety of fruit and vegetable products, thus contributing to consumer health protection.

The purpose of this study was to establish the current state of knowledge on industrial produce decontamination techniques and to identify and prioritise research gaps regarding practical and effective mechanisms to reduce microbial loading of produce with particular reference to industrially cut, washed and prepared fresh produce. Using suitable keywords, a literature review was executed using academic databases and industry sources to identify current literature on different decontamination technologies. Efficacy of approaches was compared to that of chlorine washing, the most common decontamination method used by the fresh produce industry.

Findings indicate that the identified technologies had varying efficacy of microbiological reduction when compared to chlorine, and the reductions achievable across a range of methods are limited, giving rise to food safety concerns. In addition, the results demonstrate that there has been limited consideration given to several key factors, namely industrial application of the technology approaches, organoleptic acceptability of the product, whether the microbiological reduction could be sustained throughout the life of the product and consumer acceptability of the technology. This preliminary study has highlighted concerns about the efficacy of existing produce decontamination techniques and identified research gaps regarding efficacy and industrial application of new decontamination technologies.


Highlights

► The paper investigates current literature on fresh produce decontamination methods. ► Microbiological reduction is evaluated for various decontamination technologies. ► Different technologies have varying efficacy on microbiological reduction. ► Highlights a need for practical alternatives to chlorine washing to be found. ► Suggests further work on industrial use, organoleptic and consumer acceptability.

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Keywords

  • Fresh produce microbiological decontamination;
  • Fresh produce safety;
  • Fresh produce washing;
  • Chlorine decontamination efficacy;
  • Fresh produce and foodborne illness;
  • Fresh produce industrial processing


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Corresponding author contact information
Corresponding author. Tel.: +44 (0) 1772 893657; fax: +44 (0) 1772 892927.
1
Tel.: +44 7801 608 117; fax: +33 233 46 58 57.

Copyright © 2012 Elsevier Ltd. All rights reserved.

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    Research – China’s Foodborne Illness Statistics

    Science Direct

    Abstract

    To understand the general trends and status of China’s food safety, we analyzed 2387 individual incidents of acute foodborne illnesses that had been reported by medical professionals in published journal papers during the last decade. As a result, 99,487 illnesses and 380 deaths were found in these 2387 incidents. In our analysis, we tried to understand the risks of acute foodborne illnesses and deaths corresponding to food pathogens, food location and settings, implicated food vehicles, sources of contamination and human causes. Based on our analysis, we made recommendations for risk communication, risk management and future research in regard to foodborne illnesses in China.

    Highlights

    ► We analyze China’s food safety problem in the case of acute foodborne illness. ► Data were extracted from detailed reports on 2387 incidents of foodborne illness. ► Risk factors are discussed from multiple perspectives. ► Recommendation for policies and strategies towards food safety are provided. ► This is so far the most comprehensive analysis of acute foodborne illness in China.

    UK – East Midlands Free Listeria Seminar for SME’s

    ReadyMealsInfo

    East Midlands food businesses that make, distribute and sell chilled, ready-to-eat products are to be given help and advice to help them keep their products safe from Listeria.

    According to data from the Food Standards Agency (FSA) serious cases of laboratory-confirmed Listeria infection in the UK almost doubled between 2000 and 2009. In 2010 numbers decreased but were still higher than during the 1990s.
    The Food and Drink iNet, which is run by trade organisation The Food and Drink Forum, is funding a six-month collaborative research and development project at The University of Nottingham working with the food hygiene specialists Diversey, to turn the spotlight on the issue.

    As part of the project, a seminar is being run to give small and medium-sized businesses in the chilled food sector, guidance and advice about how to manage the risk of Listeria.  The seminar will be held in the Plant Sciences Building at the University’s Sutton Bonington campus between 4 pm and 6.45 pm on Wednesday February 13.

    The Food and Drink iNet, which is part-funded by the European Regional Development Fund (ERDF), is managed by a consortium, led by the Food and Drink Forum and including Nottingham Trent University, the University of Lincoln, and The University of Nottingham. It is based at Southglade Food Park, Nottingham, with advisors covering the East Midlands region to offer a range of support to small and medium-sized enterprises that work in the sector.

    To book places at the seminar email iNet advisor Jo Murphy at jo.murphy@foodanddrink-inet.org.uk and for more information visit www.foodanddrink-inet.org.uk

     

     

    UK – FSA Publishes its Science Priorties 2013

    FSAfood_standards_agency_logo

    The Food Standards Agency has published its Forward Evidence Plan for 2013. The plan outlines priority science and evidence activities for the coming year, including potential areas for research funding and workshops that will help develop the Agency’s evidence base.

    USA – Research -STEC Sampling and Listeria Outbreaks 1998-2008

    FSIS Notice

     This notice provides new instructions to inspection program personnel (IPP) for verifying and documenting the sample source (beef, veal, or mixed) in the Public Health Information System (PHIS) when collecting raw beef samples under FSIS’s verification testing programs for Shiga toxin-producing Escherichia coli (STEC).

    CDC

    Listeria monocytogenes, a bacterial foodborne pathogen, can cause meningitis, bacteremia, and complications during pregnancy. This report summarizes listeriosis outbreaks reported to the Foodborne Disease Outbreak Surveillance System of the Centers for Disease Control and Prevention during 1998–2008. The study period includes the advent of PulseNet (a national molecular subtyping network for outbreak detection) in 1998 and the Listeria Initiative (enhanced surveillance for outbreak investigation) in 2004. Twenty-four confirmed listeriosis outbreaks were reported during 1998–2008, resulting in 359 illnesses, 215 hospitalizations, and 38 deaths. Outbreaks earlier in the study period were generally larger and longer. Serotype 4b caused the largest number of outbreaks and outbreak-associated cases. Ready-to-eat meats caused more early outbreaks, and novel vehicles (i.e., sprouts, taco/nacho salad) were associated with outbreaks later in the study period. These changes may reflect the effect of PulseNet and the Listeria Initiative and regulatory initiatives designed to prevent contamination in ready-to-eat meat and poultry products.

    Research – Bacillus cereus Enterotoxin Testing

    Liebert Open Acesss

    Currently, three commercial kits for Bacillus cereus enterotoxins Nhe and/or Hbl detection are available, namely, the Bacillus diarrheal enterotoxin visual immunoassay (BDE VIA™) kit (3M Tecra), B. cereus enterotoxin reversed passive latex agglutination (BCET-RPLA) kit (Oxoid), and the Duopath® Cereus Enterotoxins (Merck). The performance of the kits and their applicability to gastrointestinal simulation samples were evaluated. Then, the stability and production of enterotoxins Hbl and Nhe under gastrointestinal conditions were investigated. Enterotoxin production was absent or impaired at acidic pH, i.e., in gastric medium with pH 5.0 and lasagne verde with pH 5.5. B. cereus did produce enterotoxins Nhe and Hbl during anaerobic growth in intestinal medium at pH 7.0, but the toxins were instantly degraded by the enzymes in the host’s digestive secretions. Preformed enterotoxins did not withstand gastrointestinal passage under the simulated conditions, which suggests that preformed enterotoxins in food do not contribute to the diarrheal food poisoning syndrome. In conclusion, diarrhea is probably caused by de novo enterotoxin production by B. cereus cells located closely to the host’s intestinal epithelium.

    Research – New study sheds light on how Salmonella spreads in the body

    Eureka Alert

    Findings of Cambridge scientists, published today in the journal PLoS Pathogens, show a new mechanism used by bacteria to spread in the body with the potential to identify targets to prevent the dissemination of the infection process.

    Salmonella enterica is a major threat to public health, causing systemic diseases (typhoid and paratyphoid fever), gastroenteritis and non-typhoidal septicaemia (NTS) in humans and in many animal species worldwide. In the natural infection, salmonellae are typically acquired from the environment by oral ingestion of contaminated water or food or by contact with a carrier.  Current vaccines and treatments for S. enterica infections are not sufficiently effective, and there is a need to develop new therapeutic strategies.

    Dr Andrew Grant, lead author of the study from the University of Cambridge, said: “A key unanswered question in infectious diseases is how pathogens such as Salmonella grow at the single-cell level and spread in the body.  This gap in our knowledge is hampering our ability to target therapy and vaccines with accuracy.”