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Shiga toxin-producing Escherichia coli (STEC) infections are a significant public health issue, with foodborne transmission causing >1 million illnesses worldwide each year. We conducted a systematic review and meta-analysis (PROSPERO registry # CRD42017074239), to determine the relative association of different food types with sporadic illnesses caused by STEC. Searches were conducted from 01 August to 30 September 2017, using bibliographic and grey literature databases, websites and expert consultation. We identified 22 case-control studies of sporadic STEC infection in humans, from 10 countries within four World Health Organization subregions, from 1985 to 2012. We extracted data from 21 studies, for 237 individual measures in 11 food categories and across three status types (raw or undercooked, not raw and unknown). Beef was the most significant food item associated with STEC illness in the Americas and Europe, but in the Western Pacific region, chicken was most significant. These findings were not significantly moderated by the raw or cooked status of the food item, nor the publication year of the study. Data from the African, South-East Asian and Eastern Mediterranean subregions were lacking and it is unclear whether our results are relevant to these regions.

Peanut skin extract (PSE) and grape seed extract (GSE) are derived from waste products in the wine and peanut industries, respectively. Both have high concentrations of polyphenols, known to possess antioxidant and antimicrobial properties. PSE primarily contains “A-type” procyanidins, while GSE primarily contains “B-type” procyanidins. These differ structurally, but are both isomers of epicatechin dimers. The objective of this study was to evaluate the antimicrobial effects of PSE containing A-type procyanidins and GSE containing B-type procyanidins against select foodborne pathogens (Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium). The minimum inhibitory concentration (MIC) of the two extracts on L. monocytogenes, E. coli O157:H7, and S. Typhimurium was determined using the pour plate method. GSE had a significantly lower MIC (p ≤ .05) than PSE for L. monocytogenes (GSE = 60.6 ppm, PSE > 68.2 ppm) and S. Typhimurium (GSE = 45.7 ppm, PSE = 60.6 ppm), but no difference in inhibition of E. coli O157:H7. Since GSE contributed to greater inhibition, GSE extract was fractionated into monomer-rich (consisting primarily of catechins, epicatechins, and epicatechin gallates) and oligomer-rich (consisting of dimers, trimers, tetramers, up to decamers) components. Growth curves of all three pathogens in the presence of full extract, monomer and oligomer fractions were compared separately. None of the extracts inhibited S. Typhimurium growth. Generally, the extract containing greater oligomer components inhibited growth of L. monocytogenes and E. coli O157:H7 when compared to the control. Results indicate that an extract with type B procyanidins higher in oligomers may have greater antimicrobial properties. Published version

Within a microbial risk assessment framework, modeling the maximum population density (MPD) of a pathogenic microorganism is important but often not considered. This paper describes a model predicting the MPD of Salmonella on alfalfa as a function of the initial contamination level, the total count of the indigenous microbial population, the maximum pathogen growth rate and the maximum population density of the indigenous microbial population. The model is parameterized by experimental data describing growth of Salmonella on sprouting alfalfa seeds at inoculum size, native microbial load and Pseudomonas fluorescens 2-79. The obtained model fits well to the experimental data, with standard errors less than ten percent of the fitted average values. The results show that the MPD of Salmonella is not only dictated by performance characteristics of Salmonella but depends on the characteristics of the indigenous microbial population like total number of cells and its growth rate. The model can improve the predictions of microbiological growth in quantitative microbial risk assessments. Using this model, the effects of preventive measures to reduce pathogenic load and a concurrent effect on the background population can be better evaluated. If competing microorganisms are more sensitive to a particular decontamination method, a pathogenic microorganism may grow faster and reach a higher level. More knowledge regarding the effect of the indigenous microbial population (size, diversity, composition) of food products on pathogen dynamics is needed in order to make adequate predictions of pathogen dynamics on various food products.

Background: Ethiopia bears the largest burden of foodborne diseases in Africa, and diarrheal diseases are the second leading causes of premature deaths. Enterohemorrhagic Escherichia coli O157 causes an asymptomatic infection to severe diarrhea and/or hemolytic-uremic syndrome in humans. Methods: A total of 440 beef carcass and in-contact surface swabs from 55 butcher shops and 85 minced beef samples from 40 restaurants in central Ethiopia were collected and examined for the presence of E. coli O157. Standard microbiological methods were used to isolate and identify E. coli O157 and to characterize the antimicrobial resistance of the isolates. Results: E. coli O157 was detected in 4.5% carcass swabs (n = 5) and 3.6% cutting board swabs (n = 4) samples from butcher shops. E. coli O157 was not detected in any of the minced beef samples obtained from restaurants. All isolates (n = 9) were 100% susceptible to five drugs, but five isolates were resistant to amoxicillin, two isolates to streptomycin and three isolates to chloramphenicol. One isolate was resistant to two drugs and another to three drugs. Conclusions: The present study shows a low prevalence of E. coli O157 in beef sold at butcher shops. Nevertheless, given the low infective dose of this pathogen and the deep-rooted tradition of consuming raw or undercooked beef, the current prevalence should not be considered lightly from a public health perspective.

Meatball samples were irradiated using a Co-60 irradiation source (with the dose of 1, 3, 5 and 7 kGy) and stored (1, 2 and 3 weeks at 4A degrees C) to appraise some physicochemical properties and the fatty acid composition. The physicochemical results showed no significant differences in moisture, protein, fat and ash content of meatballs because of irradiation. However, total acidity, peroxide and thiobarbituric acid (TBA) values increased significantly as a result of irradiation doses and storage period. The fatty acid profile in meatball samples changed with irradiation. While saturated fatty acids (C16:0, C17:0, C18:0, and C20:0) increased with irradiation, monounsaturated (C14:1, C15:1, C18:1, and C20:1) and polyunsaturated (C18:2, C18:3, and C22:2) fatty acids decreased with irradiation. Trans fatty acids (C16:1trans, C18:1trans, C18:2trans, C18:3trans) increased with increasing irradiation doses. Meatball samples irradiated at 7 kGy had the highest total trans fatty acid content. This research shows that some physicochemical properties and fatty acid composition of meatballs can be changed by gamma irradiation.

This study aimed to determine the prevalence of Escherichia coli O157 in retail red meat and meat products with the Vitek Immunodiagnostic Assay System, including H7 Escherichia coli phage technology (VIDAS ECPT), and a real-time polymerase chain reaction system (LightCycler PCR; LCPCR). A total of 106 red meat and meat product samples were analyzed with VIDAS ECPT and LCPCR. VIDAS ECPT presumptive positive samples were subjected to VIDAS Immuno Concentration E. coli O157, followed by culture and serology. Among the 27 out of 72 (37.50%) red meat samples and 3 out of 34 (8.82%) red meat products that tested positive by VIDAS ECPT, 5.55% and 0.00% were confirmed positive for E. coli O157 (but not H7), respectively. Red meat and red meat product samples were 73.61% and 20.58% positive by LCPCR. The 5.55% prevalence of E. coli O157 in red meats poses a significant risk for consumers and indicates insufficient hygiene management both at the farm and during the slaughtering and meat handling processes in Turkey. This is the first report on the detection of E. coli O157 by VIDAS ECPT and LCPCR in naturally contaminated red meat and meat products. Bu çalışmanın amacı, Escherichia coli O157 (E. coli O157)’yi de içeren Escherichia coli Vitek Ultra Performans Immunodiagnostik Assay Sistemi Faj Teknolojisi (VIDAS ECPT) ve bir gerçek zamanlı Polimeraz Zincir Reaksiyonu sistemi (LightCycler PCR- LCPCR) ile kırmızı etlerde ve et ürünlerinde E. coli O157’nin prevalansının belirlenmesidir. Çalışmada, 106 kırmızı et ve et ürünü örneği VIDAS ECPT ve LCPCR ile analiz edildi. VIDAS ECPT şüpheli pozitif örnekler, VIDAS Immuno-konsantrasyon E. coli O157 (ICE) testine tabi tutuldu, ardından kültür ve seroloji uygulandı. VIDAS ECPT ile 72 kırmızı et örneğinin 27’si (% 37,50) ve 34 et ürünü örneğinin 3’ü (% 8,82) pozitif iken, bu örneklerin sırasıyla % 5,55 ve % 0,00 oranında E. coli O157 (H7 hariç) pozitif olduğu doğrulandı. Kırmızı et örneklerinin % 73,61’inin, kırmızı et ürünü örneklerinin ise % 20,58’inin LCPCR ile E. coli O157 pozitif olduğu belirlendi. Sonuç olarak, kırmızı etlerde % 5,55 oranında E. coli O157 bulunması tüketici yönünden risk oluşturmaktadır. Bu durum ülkemizde çift lik, kesimhane ve et işleme yerlerinde hijyen koşullarının yetersizliğinin bir göstergesidir. Bu çalışma, doğal kontamine kırmızı et ve et ürünlerinde E. coli O157’nin varlığının VIDAS ECPT ve LCPCR ile belirlendiği rapor edilen ilk çalışmadır

The prevalence of Shigella and Salmonella in a range of foodstuffs purchased from supermarkets and smaller units in Bursa province (Turkey) over a 7-month period between December 2004 and June 2005 was evaluated. In total 416 food samples composed from chicken parts, minced meats, ready-to-eat salads, raw vegetables and raw milks were analysed. Among the samples only one chicken thigh sample (0.24%) was found to be contaminated with Salmonella whereas Shigella was not isolated from any samples. Isolated Salmonella strain was serotyped as Salmonella enterica subsp. enterica serovar Infantis (S. Infantis) and displayed multidrug resistance to several antibiotics including streptomycin, tetracycline, sulphonamides, trimethoprim, trimethoprim-sulphamethoxazole and nalidixic acid. Decreased susceptibility to ciprofloxacin (MIC 0.38 mg/L by E-test) was also determined. The present study revealed that despite low contamination rate, foodstuffs particularly chicken parts could be a potential vehicle for foodborne infections and implementation of preventive measures and consumer food safety education efforts are needed.

Foods associated with Clostridium perfringens outbreaks are usually abused after cooking. Because of their short generation times, C. perfringens spores and cells can grow out to high levels during improper cooling. Therefore, the potential of C. perfringens to multiply in Dutch pea soup during different cooling times was investigated. Tubes of preheated pea soup (50 degrees C) were inoculated with cocktails of cells or heat-activated spores of this pathogen. The tubes were linearly cooled to 15 degrees C in time spans of 3, 5, 7.5, and 10 h and were subsequently stored in a refrigerator at 3 or 7 degrees C for up to 84 h. Cell numbers increased by 1-log cycle during the 3-h cooling period and reached their maximum after 10 h of cooling. Subsequent refrigeration hardly reduced cell numbers. Cooling of 3.75 liters of pea soup in an open pan showed that this amount of pea soup cooled from 50 to 15 degrees C in 5 h, which will allow a more than 10-fold increase in cell numbers. These findings emphasize the need of good hygienic practices and quick cooling of heated foods after preparation.