Detection of the plasmid-mediated mcr-1 gene conferring colistin resistance in human and food isolates of Salmonella enterica and Escherichia coli in England and Wales

• Published in: Journal of antimicrobial chemotherapy Vol. 71; no. 8; pp. 2300 - 2305
• Main Authors: Doumith, Michel, Godbole, Gauri, Ashton, Philip, Larkin, Lesley, Dallman, Tim, Day, Martin, Day, Michaela, Muller-Pebody, Berit, Ellington, Matthew J., de Pinna, Elizabeth, Johnson, Alan P., Hopkins, Katie L., Woodford, Neil
• Format: Journal Article
• Language: English
• Published: England 01.08.2016
• Subjects: Adolescent; Adult; Aged; Anti-Bacterial Agents - pharmacology; Child; Child, Preschool; Colistin - pharmacology; Computational Biology; Drug Resistance, Bacterial; England; Enterobacteriaceae - drug effects; Enterobacteriaceae - genetics; Enterobacteriaceae - isolation & purification; Enterobacteriaceae Infections - microbiology; Female; Food Microbiology; Genes, Bacterial; Humans; Male; Middle Aged; Plasmids; Retrospective Studies; Sequence Analysis, DNA; Wales; Young Adult
• ISSN: 0305-7453; 1460-2091; 1460-2091
• DOI: 10.1093/jac/dkw093

In response to the first report of transmissible colistin resistance mediated by the mcr-1 gene in Escherichia coli and Klebsiella spp. from animals and humans in China, we sought to determine its presence in Enterobacteriaceae isolated in the UK. The PHE archive of whole-genome sequences of isolates from surveillance collections, submissions to reference services and research projects was retrospectively analysed for the presence of mcr-1 using Genefinder. The genetic environment of the gene was also analysed. Rapid screening of the genomes of ∼24 000 Salmonella enterica, E. coli, Klebsiella spp., Enterobacter spp., Campylobacter spp. and Shigella spp. isolated from food or humans identified 15 mcr-1-positive isolates. These comprised: 10 human S. enterica isolates submitted between 2012 and 2015 (8 Salmonella Typhimurium, 1 Salmonella Paratyphi B var Java and 1 Salmonella Virchow) from 10 patients; 3 isolates of E. coli from 2 patients; and 2 isolates of Salmonella Paratyphi B var Java from poultry meat imported from the EU. The mcr-1 gene was located on diverse plasmids belonging to the IncHI2, IncI2 and IncX4 replicon types and its association with ISApl1 varied. Six mcr-1-positive S. enterica isolates were from patients who had recently travelled to Asia. Analysis of WGS data allowed rapid confirmation of the presence of the plasmid-mediated colistin resistance gene mcr-1 in diverse genetic environments and plasmids. It has been present in E. coli and Salmonella spp. harboured by humans in England and Wales since at least 2012.