A study by Public Health England laboratories was initiated following a multi-country outbreak of listeriosis associated with sweet corn. Data on Listeria occurrence and the levels of E. coli in frozen fruit or vegetables collected at retail or at catering in the UK have not been previously available.
Between December 2018 and April 2019, 1050, frozen fruit and vegetable samples were collected. Of these, 99% were of a satisfactory or borderline microbiological quality. Eleven samples (1%) contained ≥100 cfu/g of Escherichia coli. Listeria monocytogenes or other Listeria species were detected in six samples (2%) of fruit compared to 167 samples (24%) of vegetables and six samples (26%) of fruit and vegetable mixes, but none at a level of ≥100 cfu/g. Characterization by WGS of 74 L. monocytogenes isolates identified ten genetic clusters indicating a common source. There were 78 samples (7%) from which L. monocytogenes were detected and 101 (10%) from which other Listeria species were detected. @ https://www.sciencedirect.com/science/article/pii/S0168160520303433