A survey of Salmonella, Escherichia coli, and antimicrobial resistance in frozen, part-cooked, breaded, or battered chicken products on retail sale in the UK.

AIM: Frozen, breaded chicken products have been implicated in Salmonella outbreaks, and may be incorrectly perceived as ready-to-eat, leading to mishandling or undercooking by consumers. This study aimed to assess the prevalence of Salmonella and antimicrobial resistant (AMR) Escherichia coli in these products. METHODS AND RESULTS: Samples of frozen, raw, or partly cooked, coated chicken products were collected between April and July 2021 from retailers in the UK and tested for Salmonella spp., generic E. coli, extended spectrum beta-lactamase-producing, colistin-resistant, and carbapenem-resistant E. coli. One isolate of each bacterial type from each sample was selected for minimum inhibitory concentration determination for a range of antimicrobials. Salmonella was detected in 5 of 310 (1.6%) samples, identified as Salmonella Infantis in three samples and Salm. Java in two. One Salm. Infantis isolate was multidrug resistant, while the other Salmonella isolates were each resistant to at least one class of antimicrobials. Generic E. coli were detected in 113 samples (36.4%), with multidrug resistance being demonstrated in 20.0% of these. Escherichia coli with the ESBL phenotype were detected in 15 (4.8%) of samples and the AmpC phenotype in 2 (0.6%). A colistin-resistant E. coli was isolated from one sample; this possessed the mcr-1 gene. No carbapenem-resistant E. coli were detected. The five Salmonella-positive samples from this study, together with 20 Salmonella-positive products from an earlier study in 2020/2021, were cooked according to the manufacturers' instructions. Following cooking, Salmonella was not detected in any samples. CONCLUSIONS: This survey demonstrates continued contamination of frozen, coated chicken products with Salmonella, and provides data on the prevalence of AMR in these products.

Molecular epidemiology and population structure of the honey bee brood pathogen Melissococcus plutonius.

Melissococcus plutonius is the causative agent of European foulbrood (EFB), which is a serious brood disease of the European honey bee (Apis mellifera). EFB remains a threat because of a poor understanding of disease epidemiology. We used a recently published multi-locus sequence typing method to characterise 206 M. plutonius isolates recovered from outbreaks in England and Wales over the course of 2 years. We detected 15 different sequence types (STs), which were resolved by eBURST and phylogenetic analysis into three clonal complexes (CCs) 3, 12 and 13. Single and double locus variants within CC3 were the most abundant and widespread genotypes, accounting for 85% of the cases. In contrast, CCs 12 and 13 were rarer and predominantly found in geographical regions of high sampling intensity, consistent with a more recent introduction and localised spread. K-function analysis and interpoint distance tests revealed significant geographical clustering in five common STs, but pointed to different dispersal patterns between STs. We noted that CCs appeared to vary in pathogenicity and that infection caused by the more pathogenic variants is more likely to lead to honey bee colony destruction, as opposed to treatment. The importance of these findings for improving our understanding of disease aetiology and control are discussed.