An assessment of the microbiological quality and safety of unpasteurised milk cheese for sale in England during 2019 - 2020.

Cheese made with unpasteurised milk has been associated with outbreaks of illness. However, there are limited data on the prevalence of shiga-toxin producing E. coli (STEC) in these products, and a lack of clarity over the significance of E. coli as general indicators of hygiene in raw milk cheeses. The aim of this study was to provide further data to address both of these issues as well as assessing the overall microbiological quality of raw milk cheeses available to consumers in England. A total of 629 samples of cheese were collected from retailers, catering premises and manufacturers throughout England. The majority (80%) were made using cow's milk with 14% made from sheep's milk and 5% from goat's milk. Samples were from 18 different countries of origin, with the majority originating from either the UK (40%) or France (35%). When interpreted against EU microbiological criteria and UK guidance, 82% were considered to be of satisfactory microbiological quality, 5% were borderline and 12% were unsatisfactory. Four samples (0.6%) were potentially injurious to health due to the isolation of STEC from one, >10 4 cfu/g of coagulase positive staphylococci in two and >100 cfu/g of Listeria monocytogenes in the fourth sample. Indicator E. coli and Listeria species were detected more frequently in soft compared to hard cheese. Higher levels of indicator E. coli were significantly associated with a greater likelihood of detecting shiga toxin genes ( stx 1 and/or stx 2).