Whole genome sequencing reveals antimicrobial resistance determinants (AMR genes) of Salmonella enterica recovered from raw chicken and ready-to-eat leaves imported into England between 2014 and 2019
Nicola Davies, F. Jørgensen, C. Willis, Jim McLauchlin, Marie Anne Chattaway
Abstract
AIMS: To compare the antimicrobial resistance (AMR) genes in a genetically diverse group of Salmonella enterica recovered from foods imported into England between 2014 and 2018. METHODS AND RESULTS: Whole genome sequence was used to detect AMR genes or chromosomal mutations associated with AMR in Salmonella recovered from edible leaves imported from Asia (n = 115) as compared to Salmonella (n = 231) isolated from raw chicken, 74% originated from South America. Among isolates from edible leaves, three (3%) showed resistance to at least one antimicrobial agent, two (2%) of which were multidrug resistant (MDR, resistance to three or more antimicrobial classes). Resistance to at least one antimicrobial agent was detected in 214 (93%) in the chicken isolates, with 164 (71%) showing MDR. Genetic diversity and AMR profiles were highly heterogeneous across the different serovars. CONCLUSIONS: Resistance was rare among the Salmonella isolates from edible leaves but common (including MDR) among those from raw chicken. SIGNIFICANCE AND IMPACT OF THE STUDY: Surveillance of AMR in imported foods is essential for monitoring the risk of transmission of resistance from the food chain to humans and provides added public health value to pre-existing controls of the food chain.