Challenges and approaches to reducing foodborne illness

Comparison of enrichment methods for isolating Enterohemorrhagic Escherichia coli in kimchi

This study was conducted to compare the efficiency of four enrichment methods of Enterohemorrhagic Escherichia coli by using the 16S rRNA amplicon sequencing and a predictive model. Four different methods (US FDA, ISO, Japan Food Hygiene Association and Korea Ministry of Food and Drug Safety) were used to enrich EHEC in kimchi inoculated with cocktails of EHEC strains (NCCP 13720, NCCP 13721, and NCCP 14134). The maximum growth rate (μ_max) and lag phase duration (LPD) were compared using the Baranyi model, and 16S rRNA targeted sequencing was performed with samples at the end of the exponential phase. As a result, the μ_max and LPD values of Baranyi model developed for the four enriched media ranged from 0.82 to 0.92 and from 2.35 to 2.68, respectively, suggesting that the growth of EHEC was similar in all four enrichment media. As for the relative abundance of the bacterial composition at the family level, Enterobacteriaceae was identified as the major component (>50%) in all four enriched media. The relative abundance of Enterobacteriaceae was highest (>90%) in the two enriched media with 20 mg/L novobiocin, demonstrating that significant growth of non-targeted bacteria takes place in enrichment broths utilizing <20 mg/L novobiocin or different antibiotics. In conclusion, this study suggests that all four enrichment broth are suitable for growing EHEC in kimchi and the use and concentration of antibiotics such as novobiocin in enrichment media may have a critical role in species diversity.

A Systematic Review of the Use of Social Media for Food Safety Risk Communication

This article covers the current published literature related to the use of social media in food safety and infectious disease communication. The aim was to analyze literature recommendations and draw conclusions about how best to utilize social media for food safety risk communication going forward. A systematic literature review was conducted, and 24 articles were included for analysis. The inclusion criteria were (i) original peer-reviewed articles and (ii) primary focus on communication through social media about food safety and/or infectious diseases. Studies were coded for themes about social media applications, benefits, limitations, and best practices. Trust and personal beliefs were important drivers of social media use. The wide reach, immediacy, and information gathering capacities of social media were frequently cited benefits. Suggestions for social media best practices were inconsistent among studies, and study designs were highly variable. More evidence-based suggestions are needed to better establish guidelines for social media use in food safety and infectious disease risk communication. The information gleaned from this review can be used to create effective messages for shaping food safety behaviors.

Pathogens of Food Animals: Sources, Characteristics, Human Risk, and Methods of Detection

Pathogens associated with food production (livestock) animals come in many forms causing a multitude of disease for humans. For the purpose of this review, these infectious agents can be divided into three broad categories: those that are associated with bacterial disease, those that are associated with viruses, and those that are parasitic in nature. The goal of this chapter is to provide the reader with an overview of the most common pathogens that cause disease in humans through exposure via the food chain and the consequence of this exposure as well as risk and detection methods. We have also included a collection of unusual pathogens that although rare have still caused disease, and their recognition is warranted in light of emerging and reemerging diseases. These provide the reader an understanding of where the next big outbreak could occur. The influence of the global economy, the movement of people, and food makes understanding production animal-associated disease paramount to being able to address new diseases as they arise.

Making One Health a Reality--Crossing Bureaucratic Boundaries

A One Health approach requires that nontraditional partners with differing mandates collaborate and communicate effectively. Barriers to such redefined relationships range from personality and institutional cultural and value differences to impediments that require changes in agency-specific policies. This article reviews interagency One Health collaborations, nationally and internationally. It presents a series of case studies that describe situations in which barriers were overcome, thus culminating in successful One Health outcomes. The case studies illustrate challenges, tipping points, and externally enabling factors that help institutionalize cross-bureaucratic working relationships. Likewise, the cases demonstrate the added value of taking a One Health approach to solving (or preventing) public health problems.

Resilient information networks for coordination of foodborne disease outbreaks

Foodborne disease outbreaks are increasingly being seen as a greater concern by public health authorities. It has also become a global research agenda to identify improved pathways to coordinating outbreak detection. Furthermore, a significant need exists for timely coordination of the detection of potential foodborne disease outbreaks to reduce the number of infected individuals and the overall impact on public health security. This study aimed to offer an effective approach for coordinating foodborne disease outbreaks. First, we identify current coordination processes, complexities, and challenges. We then explore social media surveillance strategies, usage, and the power of these strategies to influence decision-making. Finally, based on informal (social media) and formal (organizational) surveillance approaches, we propose a hybrid information network model for improving the coordination of outbreak detection.

Eating out is associated with self-reported food poisoning: a Western Australia population perspective, 1998 to 2009

OBJECTIVE

To explore factors associated with self-reported food poisoning among Western Australian adults between 1998 and 2009.

DESIGN

Data were pooled from four Nutrition Monitoring Surveys Series which included information on suspected food poisoning among Western Australian adults. Descriptive statistics and multinomial regression analyses were used to describe factors associated with self-reported food poisoning, food safety knowledge and behaviours.

SETTING

Population of Western Australia estimated to be 2·5 million in 2009.

SUBJECTS

A representative sample of 4494 adults aged between 18 and 64 years.

RESULTS

There was no significant change in self-reported food poisoning over time, with about 18 % saying they had suspected food poisoning in the last 6 months. Overall, 2·1% said they had confirmed their food-borne illness with a nurse of doctor. People less than 34 years old, those with a university degree and people who ate meals out on the day prior to the survey (one meal: OR = 1·30, 95% CI 1·04, 1·62; two meals: OR = 2·21, 95% CI 1·30, 3·76) were the most likely to report food poisoning. Younger people were also more likely to have their food poisoning confirmed by a health professional. Use of refrigerator thermometers and cool bags for storing food increased significantly between 2004 and 2009.

CONCLUSIONS

Findings support the inclusion of food safety advice in dietary recommendations. Food safety and handling education and training is recommended for food businesses, particularly the takeaway food sector, and for consumers. Because food poisoning is reported more often by younger people, food safety education should begin during childhood.

Online reports of foodborne illness capture foods implicated in official foodborne outbreak reports

OBJECTIVE

Traditional surveillance systems capture only a fraction of the estimated 48 million yearly cases of foodborne illness in the United States. We assessed whether foodservice reviews on Yelp.com (a business review site) can be used to support foodborne illness surveillance efforts.

METHODS

We obtained reviews from 2005 to 2012 of 5824 foodservice businesses closest to 29 colleges. After extracting recent reviews describing episodes of foodborne illness, we compared implicated foods to foods in outbreak reports from the U.S. Centers for Disease Control and Prevention (CDC).

RESULTS

Broadly, the distribution of implicated foods across five categories was as follows: aquatic (16% Yelp, 12% CDC), dairy-eggs (23% Yelp, 23% CDC), fruits-nuts (7% Yelp, 7% CDC), meat-poultry (32% Yelp, 33% CDC), and vegetables (22% Yelp, 25% CDC). The distribution of foods across 19 more specific food categories was also similar, with Spearman correlations ranging from 0.60 to 0.85 for 2006-2011. The most implicated food categories in both Yelp and CDC were beef, dairy, grains-beans, poultry and vine-stalk.

CONCLUSIONS

Based on observations in this study and the increased usage of social media, we posit that online illness reports could complement traditional surveillance systems by providing near real-time information on foodborne illnesses, implicated foods and locations.

Incidence of Escherichia coli O157:H7 and E. coli virulence factors in US bulk tank milk as determined by polymerase chain reaction

Samples of bulk tank milk from dairies across the United States, taken as part of the National Animal Health Monitoring Dairy 2002 survey, were analyzed for the presence of several genes encoding virulence factors associated with enterohemorrhagic forms of Escherichia coli (EHEC) using real-time and conventional PCR assays. Samples from 859 farms in 21 states were collected and enriched in EC medium at 42.5 degrees C to amplify any E. coli present, and DNA was isolated from the resulting biomass. The eaeA gene encoding intimin, a virulence factor associated with enteropathogenic forms of E. coli and EHEC, was detected in 199 (23%) of the samples. Thirty-six samples (4.2%) were positive for eaeA, the gamma allele of the translocated intimin receptor (gamma-tir), found in EHEC strains of O157:H7, and one or both shiga-like toxin genes (stx1 and stx2), a combination that may be indicative of the presence of O157:H7 EHEC. Testing these 36 samples with a commercially available real-time PCR kit for detection of O157:H7 indicated that 5 samples could be contaminated with O157:H7. A multiplex PCR to detect the presence of fliC, rfbE, and hlyA genes found in O157:H7 reduced to 2 (0.2% of all samples) the number of samples likely to be contaminated with this organism. A strain of O157:H7 (eaeA+, gamma-tir+, stx2+, rfbE+, fliC+, hlyA+) was subsequently isolated from one sample. Thirty-four eaeA-positive samples did not contain detectable gamma-tir but did contain one or both of the stx genes suggesting the presence of EHEC strains other than O157:H7. These results indicate a low incidence of O157:H7 in bulk tank milk but suggest that a risk from other enteropathogenic and EHEC forms of E. coli may exist and that PCR targeting virulence factors associated with highly pathogenic forms of E. coli may be an effective means of detecting potential dangers in raw milk.

Indirect measurement of the lag time distribution of single cells of Listeria innocua in food

The distribution of log counts at a given time during the exponential growth phase of Listeria innocua measured in food samples inoculated with one cell each was applied to estimate the distribution of the single-cell lag times. Three replicate experiments in broth showed that the distribution of the log counts is a linear mapping of the distribution of the detection times measured by optical density. The detection time distribution reflects the lag time distribution but is shifted in time. The log count distribution was applied to estimate the distributions of the lag times in a liquid dairy product and in liver paté after different heat treatments. Two batches of ca. 100 samples of the dairy product were inoculated and heated at 55 degrees C for 45 min or at 62 degrees C for 2 min, and an unheated batch was incubated at 4 degrees C. The final concentration of surviving bacteria was ca. 1 cell per sample. The unheated cells showed the shortest lag times with the smallest variance. The mean and the variance of the lag times of the surviving cells at 62 degrees C were greater than those of the cells treated at 55 degrees C. Three batches of paté samples were heated at 55 degrees C for 25 min, 62 degrees C for 81 s, or 65 degrees C for 20 s. A control batch was inoculated but not heated. All paté samples were incubated at 15 degrees C. The distribution of the lag times of the cells heated at 55 degrees C was not significantly different from that of the unheated cells. However, at the higher temperatures, 62 degrees C and 65 degrees C, the lag duration was longer and its variance greater.

Superantigen genes encoded by the egc cluster and SaPIbov are predominant among Staphylococcus aureus isolates from cows, goats, sheep, rabbits and poultry

In recent years several new staphylococcal enterotoxins (SEs) have been described, which currently have largely unknown frequencies of occurrence and roles in human or animal disease. One hundred and ninety-one Staphylococcus aureus isolates from cows (99), goats (39), sheep (23), rabbits (15), chickens (15) and a cat (1) were screened for SE genes sea-see, seg-seo and seq and for the tst gene encoding staphylococcal toxic shock syndrome toxin-1 using multiplex PCRs and individual PCRs for the seb and sek genes. One hundred and ten isolates tested positive for at least one of these 16 superantigen (SAg)-encoding genes. There were statistically significant differences in the frequencies of some of these SAg genes between isolates from different animals. No strain possessed either the sea or see gene. The sec gene was present in 51 isolates, the sed gene in eight and the seb gene in one. The seh gene was found in four strains and the sek and seq genes together in one isolate. The most common combinations of genes were the egc cluster, bearing the seg, sei, sem, sen and seo genes, in 47 isolates, the sec, sel and tst gene combination typical of the SaPIbov pathogenicity island in 44 isolates, the egc cluster lacking the seg gene in 11 isolates, the sed and sej genes in nine isolates, and the sec and tst genes without the sel gene in seven isolates. The higher frequencies of the sec and tst genes together and the lower frequencies of the egc gene cluster among the SAg gene-positive sheep or goat isolates compared to bovine isolates were statistically significant. Of 36 bovine isolates that were mitogenic for human T lymphocytes, four were negative for the 16 SAg genes tested for, while a further 14 gave borderline results in the mitogenicity assay, 12 of which were SAg gene-negative. Twenty-nine strains lacking all the SAg genes did not induce T-cell proliferation. This survey indicates that novel SE genes seg, sei, sel, sem, sen and seo along with the sec and tst genes predominate in S. aureus from animal hosts. The mitogenicity assays indicate that further uncharacterized SAgs may be present in bovine isolates.