Inducible colistin resistance via a disrupted plasmid-borne mcr-1 gene in a 2008 Vietnamese Shigella sonnei isolate

Duy Pham Thanh, Ha Thanh Tuyen, To Nguyen Thi Nguyen, Hao Chung The, Ryan R. Wick, Guy E. Thwaites, Stephen Baker, Kathryn E. Holt

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65 Citations (Scopus)

Abstract

Objectives: The objective of this study was to assess the presence of mcr-1 in Shigella sonnei isolated in Vietnam. Methods: WGS data were analysed for the presence of the mcr-1 gene sequence. The association of mcr-1 with a plasmid was assessed by PCR and by conjugation. Results: Through genome sequencing we identified a plasmid-associated inactive form of mcr-1 in a 2008 Vietnamese isolate of Shigella sonnei. The plasmid was conjugated into Escherichia coli and mcr-1 was activated upon exposure to colistin, resulting in highly colistin-resistant transconjugants. Conclusions: This is the first description of the mcr-1 gene in Shigella, which is atypical given that colistin is not ordinarily used to treat diarrhoea. Our data suggest the mcr-1 gene has been circulating in human-restricted pathogens for some time but likely carries a selective fitness cost.

Original languageEnglish
Pages (from-to)2314-2317
Number of pages4
JournalJournal of Antimicrobial Chemotherapy
Volume71
Issue number8
DOIs
Publication statusPublished - 1 Aug 2016
Externally publishedYes

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