Occurrence and characterization of mcr-1-harbouring Escherichia coli isolated from pigs in Great Britain from 2013 to 2015. (15th December 2016)

• Record Type: Journal Article
• Authors: Duggett, Nicholas A.; Sayers, Ellie; AbuOun, Manal; Ellis, Richard J.; Nunez-Garcia, Javier; Randall, Luke; Horton, Robert; Rogers, Jon; Martelli, Francesca; Smith, Richard P.; Brena, Camilla; Williamson, Susanna; Kirchner, Miranda; Davies, Robert; Crook, Derrick; Evans, Sarah; Teale, Chris; Anjum, Muna F.
• Is Part Of: Journal of antimicrobial chemotherapy. Volume 72:Number 3(2017:Mar.)
• Page Start: 691
• Page End: 695
• Publication Date: 2016-12-15
• Subjects: Anti-infective agents -- Periodicals; Chemotherapy -- Periodicals; 615.58
• DOI: 10.1093/jac/dkw477
• Languages: English
• ISSNs: 0305-7453

Abstract

Abstract : Objectives: To determine the occurrence of mcr-1 -harbouring Escherichia coli in archived pig material originating in Great Britain (GB) from 2013 to 2015 and characterize mcr-1 plasmids. Methods: Enrichment and selective culture of 387 archived porcine caecal contents and recovery from archive of 1109 E. coli isolates to identify colistin-resistant bacteria by testing for the presence of mcr-1 by PCR and RT–PCR. mcr-1 -harbouring E. coli were characterized by WGS and compared with other available mcr-1 WGS. Results: Using selective isolation following enrichment, the occurrence of mcr-1 E. coli in caeca from healthy pigs at slaughter from unique farms in GB was 0.6% (95% CI 0%–1.5%) in 2015. mcr-1 E. coli were also detected in isolates from two porcine veterinary diagnostic submissions in 2015. All isolates prior to 2015 were negative. WGS analysis of the four mcr-1 -positive E. coli indicated no other antimicrobial resistance (AMR) genes were linked to mcr-1 -plasmid-bearing contigs, despite all harbouring multiple AMR genes. The sequence similarity between mcr-1 -plasmid-bearing contigs identified and those found in GB, Chinese and South African human isolates and Danish, French and Estonian livestock-associated isolates was 90%–99%. Conclusions: mcr-1- harbouring plasmids were diverse, implying transposable elements are involved in mcr-1 transmission in GB. The low number of mcr-1 -positive E. coli isolates identified suggested mcr-1 is currently uncommon in E. coli from pigs within GB. The high sequence similarity between mcr-1 plasmid draft genomes identified in pig E. coli and plasmids found in human and livestock-associated isolates globally requires further investigation to understand the full implications.