Tag Archives: leafy greens

Canada – CFIA – Public Health Notice – Leafy Greens – E.coliO157

CFIA Ecoli Istock

The Public Health Agency of Canada is collaborating with federal and provincial public health partners to investigate an outbreak of Escherichia coli O157:H7, commonly called E.coli, with a possible link to leafy greens. A specific product has not been identified yet, and the investigation is ongoing.

At this time, the risk to Canadians is low. However, Canadians are reminded to follow safe food handling practices to avoid illness.

E. coli are bacteria that live naturally in the intestines of cattle, poultry and other animals. Most E. coli are harmless to humans, but some varieties carry genes that allow them to cause illness.

While most people made ill by E. coli experience a few days of upset stomach and then recover fully, infections can sometimes be life threatening.

Research Articles – Pathogens in Pet Food – Salmonella low aW – Salmonella Walnuts – E.coli Leafy Greens

Ingenta Connect

Tracking an Escherichiacoli O157:H7–Contaminated Batch of Leafy Greens through a Pilot-Scale Fresh-Cut Processing Line

Ingenta Connect

Growth and Survival of Enterobacteriaceae and Inoculated Salmonella on Walnut Hulls and Maturing Walnut Fruit

Ingenta Connect

Predicting Survival of Salmonella in Low–Water Activity Foods: An Analysis of Literature Data

Mary Ann Leibert

Investigation of Listeria, Salmonella, and Toxigenic Escherichia coli in Various Pet Foods

Europe Research- Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in leafy greens eaten raw as salads)

EFSA Eurofins Food Testing UK

Leafy greens eaten raw as salads are minimally processed and widely consumed foods. Risk factors for leafy greens contamination by Salmonella spp. and Norovirus were considered in the context of the whole food chain including agricultural production and processing. Available estimates of the prevalence of these pathogens (together with the use of Escherichia coli as an indicator organism) in leafy greens were evaluated. Specific mitigation options relating to contamination of leafy greens were considered and qualitatively assessed. It was concluded that each farm environment represents a unique combination of numerous characteristics that can influence occurrence and persistence of pathogens in leafy greens production. Appropriate implementation of food safety management systems, including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should be primary objectives of leafy green producers. The relevance of microbiological criteria applicable to production, processing and at retail/catering were considered. The current legal framework does not include microbiological criteria applicable at primary production which will validate and verify GAP and GHP. It is proposed to define a criterion at primary production of leafy greens which is designated as Hygiene Criterion, and E. coli was identified as suitable for this purpose. A Process Hygiene Criterion for E. coli in leafy green packaging plants or fresh cutting plantswas considered andwill also give an indication of the degree to which GAP, GHP, GMP or HACCP programs have been implemented. A Food Safety Criterion for Salmonella in leafy greens could be used as a tool to communicate to producers and processors that Salmonella should not be present in the product. Studies on the prevalence and infectivity of Norovirus are limited, and quantitative data on viral load are scarce making establishment of microbiological criteria for Norovirus on leafy greens difficult.

© European Food Safety Authority, 2014

Research – Impact of Temperature Abuse of Leafy Greens in Transport – Safety Impact

Ingenta ConnectEurofins Food Testing UK

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

Research – Growth of Escherichia coli O157:H7 and Listeria monocytogenes in Packaged Fresh-Cut Romaine Mix at Fluctuating Temperatures during Commercial Transport, Retail Storage, and Display

Ingentaconnect

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

USA – Article – How do Pathogens get into Produce

This is a very interesting article in Food Safety News which I think would be of interest to Food Microbiologists and the Produce industry alike. the link will take you to the full article

Food Safety News

Leafy greens, lettuce, cantaloupes, mangoes and strawberries. These are just some of the foods that have sickened or even killed people when they were contaminated with foodborne pathogens such as E. coli, Listeria and Salmonella.

Amidst the confusing swirl of information about these and other produce outbreaks, the question arises: Were some of these pathogens inside the produce? Could it be — in some cases, anyway — that the plant’s roots sucked the pathogens up out of the soil and transferred them through the plant into its edible parts?