Category Archives: Research

Research – Evaluation of an Environmental Monitoring Program for the Microbial Safety of Air and Surfaces in a Dairy Plant Environment

Journal of food Protection

Microbiological hazards can occur when foodstuffs come into contact with contaminated surfaces or infectious agents dispersed by air currents in the manufacturing environment. An environmental monitoring program (EMP) is a critical aspect of sustainable and safe food manufacturing used to evaluate the effectiveness of the microbial controls in place. An effective EMP should be based on risk analysis, taking into account previous sampling history to determine the selection of the sampling points, the scope of the test, and the frequency of analysis. This study involved evaluation of the environmental monitoring regime and microbiological status of a medium-sized dairy plant manufacturing food ingredients, e.g., proteins, milk powders, and dairy fats. The data specific to microbial tests (n = 3,468), recorded across 124 fixed sampling locations over a 2-year period (2014 to 2015) from air (n = 1,787) and surfaces (n = 1,681) were analyzed. The aim of this study was to highlight the strengths and weaknesses of the EMP in a select dairy processing plant. The results of this study outline the selection of sampling locations, the scope of the test, and the frequency of analysis. An analysis of variance revealed subsections of the manufacturing areas with high risk factors, especially the packaging subsection specified for bulk packaging, the atomizer, and the fluidized bed. The temporal and spatial analysis showed the potential to reduce or relocate the monitoring effort, most notably related to total coliforms and Staphylococcus aureus, across the dairy plant due to homogeneity across the sampling subsections with little or no deviations. The results suggest a need to reevaluate the current EMP and the corrective action plan, especially with regard to detection of pathogens. Recommendations for optimization of the EMP are presented to assist the dairy industry with reviewing and revising the control measures and hazard assessment with regard to existing contamination issues.

Research – Ruminant and chicken: important sources of Campylobacteriosis in France

Poultry Med

Campylobacter spp. are regarded as the most common foodborne bacterial zoonosis in Europe, despite potential underestimation due to underreporting of cases. In France, C. jejuni is responsible for nearly 80% of human infections while C. coli accounts for around 15%. The economic burden of campylobacteriosis has been estimated to 2.4 billion euros annually in Europe, with estimates of £50 million in 2008–2009 in the United Kingdom and 82 million euros in the Netherlands in 2011.Pathogen source attribution studies are a useful tool for identifying reservoirs of human infection. Based on Multilocus Sequence Typing (MLST) data, such studies have identified chicken as a major source of C. jejuni human infection. The use of whole genome sequence-based typing methods offers potential to improve the precision of attribution beyond that which is possible from 7 MLST loci. Using published data and 156 novel C. jejuni genomes sequenced in this study, the researchers performed probabilistic host source attribution of clinical C. jejuni isolates from France using three types of genotype data: comparative genomic fingerprints; MLST genes; 15 host segregating genes previously identified by whole genome sequencing. Consistent with previous studies, chicken was an important source of campylobacteriosis in France (31–63% of clinical isolates assigned). There was also evidence that ruminants are a source (22–55% of clinical isolates assigned), suggesting that further investigation of potential transmission routes from ruminants to human would be useful.

Information – Models to develop and validate process preventive controls Decision-support for the food industry

ComBase

Computational Biology Premium (CB Premium) supports a new era of predictive microbiology and risk-based food safety (e.g. FSMA), by providing the food community with peer-reviewed models accessed via a uniform interface. Much like ComBase, CB+ serves as a repository of models and risk management tools. However, what differentiates CB+ is it’s sole focus on predictive models that have been developed for and validated in real commercial foods.

Since co-founding ComBase in 2000, Dr Mark Tamplin has interacted with numerous members of the food safety community. A universal request was for predictive models applicable to commercial foods. CB+ was designed to meet this demand.

Our Vision is that CB+ will be the leading predictive microbiology resource used by small and large food companies to develop and validate process preventive controls. Our Goals to realizing this vision involve actively engaging with the food industry to identify high demand models, and then interacting with and supporting food safety researchers who produce the predictive models that fill these information gaps.

CB+ supports all lead model authors by providing free access to CB+, as well as measuring the number of times users access individual models, thus documenting model impact.

CB+ is owned by the University of Tasmania, and produced and delivered through the Tasmania Institute of Agriculture.

Our operational team includes Mark Tamplin and Daniel Marin Hervias, the technical manager who designs the CB+ web application and software framework. In addition, a small team of scientists help identify and format new models for CB+.

Research – Staphylococcus aureus infection dynamics

Plos One 

 

Staphylococcus aureus is a human commensal that can also cause systemic infections. This transition requires evasion of the immune response and the ability to exploit different niches within the host. However, the disease mechanisms and the dominant immune mediators against infection are poorly understood. Previously it has been shown that the infecting S. aureus population goes through a population bottleneck, from which very few bacteria escape to establish the abscesses that are characteristic of many infections. Here we examine the host factors underlying the population bottleneck and subsequent clonal expansion in S. aureus infection models, to identify underpinning principles of infection. The bottleneck is a common feature between models and is independent of S. aureus strain. Interestingly, the high doses of S. aureus required for the widely used “survival” model results in a reduced population bottleneck, suggesting that host defences have been simply overloaded. This brings into question the applicability of the survival model. Depletion of immune mediators revealed key breakpoints and the dynamics of systemic infection. Loss of macrophages, including the liver Kupffer cells, led to increased sensitivity to infection as expected but also loss of the population bottleneck and the spread to other organs still occurred. Conversely, neutrophil depletion led to greater susceptibility to disease but with a concomitant maintenance of the bottleneck and lack of systemic spread. We also used a novel microscopy approach to examine abscess architecture and distribution within organs. From these observations we developed a conceptual model for S. aureus disease from initial infection to mature abscess. This work highlights the need to understand the complexities of the infectious process to be able to assign functions for host and bacterial components, and why S. aureus disease requires a seemingly high infectious dose and how interventions such as a vaccine may be more rationally developed.

Research – Multi-drug-resistant (MDR), colistin-resistant E. coli bacteria pervasive in Vietnam village

Outbreak News Today Ecoli Istock

A new study has found that the majority of residents in a rural village of Vietnam harbored multi-drug-resistant (MDR), colistin-resistant E. coli bacteria. Colistin is typically used as a last-resort treatment when there are no other therapy options available. The research is presented at ASM Microbe, the annual meeting of the American Society for Microbiology, held from June 7th to June 11th in Atlanta, GA.

“These results revealed the dissemination of MDR colistin-resistant E. coli, harboring the colistin-resistant mobile gene mcr among commensal bacteria of residents, in a rural community in Vietnam,” said Yoshimasa Yamamoto, Ph.D., Osaka University, Osaka, Japan, presenting author on the study.

The colistin-resistant bacteria were detected in 71.4% of the residents in Nguyen Xa village in Vietnam. All the colistin-resistant isolates were identified as E. coli.

Research -Incidence of Listeria spp. in Ready-to-Eat Food Processing Plant Environments Regulated by the U.S. Food Safety and Inspection Service and the U.S. Food and Drug Administration

Journal of Food Protection

A multiyear survey of 31 ready-to-eat (RTE) food processing plants in the United States was conducted to determine the incidence of Listeria spp. in various RTE production environments. Samples were collected from 22 RTE plants regulated by the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) and from 9 RTE food plants regulated by the U.S. Department of Health and Human Services’ Food and Drug Administration (FDA). Only nonfood contact surfaces in the RTE manufacturing areas with exposed RTE product were sampled. Each sample was individually analyzed for the presence of Listeria spp. by using a PCR-based rapid assay. In total, 4,829 samples were collected from various locations, including freezers, equipment framework, floors, walls, wall-floor junctures, drains, floor mats, doors, and cleaning tools. Nine (29%) of the facilities had zero samples positive for Listeria spp. in the production environment, whereas 22 (71%) had one or more samples positive for Listeria spp. The total incidence of Listeria spp. in all RTE food plants was 4.5%. The positive rate in plants regulated by the FSIS ranged from 0 to 9.7%, whereas the positive rate in plants regulated by the FDA ranged from 1.2 to 36%.

Research – Scientists map genetic codes of 3,000 dangerous bacteria

Yahoo News 

 

By Kate Kelland

(Reuters) – Scientists seeking new ways to fight drug-resistant superbugs have mapped the genomes of more than 3,000 bacteria, including samples of a bug taken from Alexander Fleming’s nose and a dysentery-causing strain from a World War One soldier.

The DNA of deadly strains of plague, dysentery and cholera were also decoded in what the researchers said was an effort to better understand some of the world’s most dangerous diseases and develop new ways to fight them.

The samples from Fleming – the British scientist credited with discovering the first antibiotic, penicillin, in 1928 – were among more than 5,500 bugs at Britain’s National Collection of Type Cultures (NCTC) one of the world’s largest collections of clinically relevant bacteria.

The first bacteria to be deposited in the NCTC was a strain of dysentery-causing Shigella flexneri that was isolated in 1915 from a soldier in the trenches of World War One.

“Knowing very accurately what bacteria looked like before and during the introduction of antibiotics and vaccines, and comparing them to current strains, … shows us how they have responded to these treatments,” said Julian Parkhill of Britain’s Wellcome Sanger Institute who co-led the research.

“This in turn helps us develop new antibiotics and vaccines.”