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

Abstract

Aim: Frozen, breaded c hic ken products have been implicated in Salmonella outbreaks, and may be incorrectly perceived as ready-to-eat, leading to mishandling or undercooking b y consumers. T his study aimed to assess the pre v alence of Salmonella and antimicrobial resistant (AMR) Esc heric hia coli in these products. Methods and results: Samples of froz en, ra w, or partly cooked, coated c hic ken products were collected between April and July 2021 from retail- ers in the UK and tested for Salmonella spp., generic E. coli , extended spectrum bet a-lact amase-producing , colistin-resist ant, 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. J a v a in two. One Salm . Infantis isolate was multidrug resistant, while the other Salmonella isolates were each resistant to at least one class of antimi- crobials. Generic E. coli were detected in 113 samples (36.4%), with multidrug resistance being demonstrated in 20.0% of these. Esc heric hia 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. T he fiv e Salmonella -positiv e 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: T his surv e y demonstrates continued contamination of froz en, coated c hic k en products with Salmonella , and pro vides data on the pre v alence of AMR in these products.