Category Archives: Enterobacteriaceae

Research – Microbial quality of edible grasshoppers Ruspolia differens (Orthoptera: Tettigoniidae): From wild harvesting to fork in the Kagera Region, Tanzania

Wiley Online Library

Abstract

In Tanzania, edible Ruspolia differens are still harvested from the natural environments. In this perspective, little is known about the microbiological quality of wild harvested R. differens. This study was conducted to assess the microbiological quality of wild harvested R. differens and evaluate the efficacy of conventional processing methods in reducing microbial load. Two districts (Bukoba rural and Muleba) within the Kagera region were purposively selected for the study. Sampling was done from the same batches along the R. differens food chain as follows: (a) at harvest points in the villages, (b) after transportation to the market and plucking of wings and legs, (c) after rinsing with potable tap water, and (d) after processing using conventional methods. Generally, high microbial counts, that is, total viable aerobic count (TVC), Enterobacteriaceae, lactic acid bacteria, bacterial endospores, and yeasts and molds were observed in raw R. differenssamples. A significant increase in microbial counts after transportation and plucking was only observed for TVC, bacterial endospores, and yeasts and molds. A statistically significant reduction in all types of counts, with the exception of bacterial endospores, was observed after processing. All processed samples analyzed were devoid of salmonellae, Listeria monocytogenes, and Escherichia coli.

Practical applications

Although commonly used processing methods of Ruspolia differens were effective in reducing microbial load, bacterial endospores were hardly eliminated and could pose a health hazard to consumers; thus, improved handling of R. differens along the food chain could reduce such risks.

RASFF Alert – Animal Feed – Enterobacteriaceae – Dried Dog Food

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RASFF – too high count of Enterobacteriaceae (2.6 x 10E3) in dried dog food from China in Germany

Research – Survival of food‐borne bacterial pathogens in traditional Mediterranean anchovy products

Wiley Online Library

Abstract

The aim of this study was to investigate the survival of Salmonella Enteritidis, Staphylococcus aureus and Listeria monocytogenes in salted and marinated anchovy (Engraulis encrasicholus). Total viable counts (TVCs), lactic acid bacteria, Enterobacteriaceae, and yeasts/molds were also enumerated. Initially, TVC was as high as 5.5 log10 cfu/g, but the population dropped down to 3.2 and 2.2 log10 CFU/g for salted and marinated anchovy, respectively. S. aureus was the most salt‐tolerant and L. monocytogenes was the most acid‐tolerant microorganism. A biphasic inactivation of S. Enteriditis and L. monocytogenes was apparent during the 8‐hr marination process, implying adaptation and resistance to low pH. Results suggest that salting or marinating of anchovy creates an environment in which pathogenic bacteria are inactivated. However, inherent resistance or possible adaptation to stresses can result to prolonged inactivation times; hence it is important to avoid contamination with high numbers of food‐borne pathogens.

Practical applications

Many food‐borne bacterial pathogens can survive at low pH and aw, especially in cases in which they might adapt to the imposed stresses and become resistant. Knowing the time required to reduce food‐borne pathogens is of great interest for ensuring safety of traditional seafood.

RASFF Alerts – Animal Feed – Enterobacteriaceae – Dog Chews – Fish Meal

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RASFF – Salmonella (presence /25g) and too high count of Enterobacteriaceae (>300, 990, 2200 CFU/g) in dog chews from Turkey in Germany

RASFF – Salmonella (presence /25g) and too high count of Enterobacteriaceae (1200 CFU/g) in fish meal from Mauritania in Spain

Research – Season and Species: Two Possible Hurdles for Reducing the Food Safety Risk of Escherichia coli O157 Contamination of Leafy Vegetables

Food Protection Eurofins Food Testing UK

The food safety risk of Shiga toxin–producing Escherichia coli (STEC) infection per serving of leafy vegetables was investigated using a quantitative microbial risk assessment (QMRA) approach. The estimated level of E. coli O157 contamination was based on observed numbers of Enterobacteriaceae and E. coli on leafy vegetables grown and processed in southern Sweden from 2014 to 2016. Samples were collected before harvest, after washing, and at the end of shelf life. The observed counts were combined with data on the ratio of E. coli to E. coli O157 taken from earlier studies to estimate the probability of illness. The risks of STEC infection associated with species, either spinach (Spinacia oleracea) or rocket (Diplotaxis tenuifolia), growing season (spring or autumn), and washing (washed or not washed) were then evaluated. The results indicated that leafy vegetable species and growing season could be possible hurdles for reducing the food safety risk of STEC infection. At harvest, the probability of infection was 87% lower when consuming rocket compared with spinach and 90% lower when consuming leafy vegetables grown in spring compared with autumn. These relative risk reductions remained consistent even with other serving sizes and dose-response models. The lowest risk of STEC infection was associated with leafy vegetables early in the production chain, i.e., before harvest, while the risk increased during storage and processing. Consequently, the highest risk was observed when leafy vegetables were consumed at the end of shelf life. Washing had no effect on the food safety risk of STEC infection in this study. To improve the quality of QMRA, there is a need for additional data on the relationship between indicator organisms that can be easily enumerated (e.g., E. coli and Enterobacteriaceae) and E. coli strains that can cause STEC infection (e.g., E. coli O157) but are difficult to identify in food samples such as leafy vegetables.

RASFF Alert – Animal Feed – Enterobacteriaceae – Dog Chews

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RASFF – too high count of Enterobacteriaceae (160; 180; 180 CFU/g) in dog chews from China in Estonia

RASFF Alerts – Animal Feed – Salmonella – Enterobacteriaceae – Dog Chews – Fish Meal

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RASFF – Salmonella enterica ser. Agona (in 1 out of 5 samples /25g) in dog chews from Germany in Austria

RASFF – too high count of Enterobacteriaceae (9000 CFU/g) in fish meal from Poland in Spain