title: Inducible colistin resistance via a disrupted plasmid-borne mcr-1 gene in a 2008 Vietnamese Shigella sonnei isolate.
abstract: The objective of this study was to assess the presence of mcr-1 in Shigella sonnei isolated in Vietnam.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Duy
authors.initials: D
authors.lastname: Pham Thanh
authors.affiliation: The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Ha
authors.initials: H
authors.lastname: Thanh Tuyen
authors.affiliation: The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: To
authors.initials: T
authors.lastname: Nguyen Thi Nguyen
authors.affiliation: The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
authors.forename: Hao
authors.initials: H
authors.lastname: Chung The
authors.affiliation: Centre for Systems Genomics, The University of Melbourne, Melbourne, Australia Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Wick
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK.
authors.forename: Guy E
authors.initials: GE
authors.lastname: Thwaites
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia Centre for Tropical Medicine and Global Health, Oxford University, Oxford, UK The London School of Hygiene and Tropical Medicine, London, UK sbaker@oucru.org.
authors.forename: Stephen
authors.initials: S
authors.lastname: Baker
authors.affiliation: Centre for Systems Genomics, The University of Melbourne, Melbourne, Australia Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Australia.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Holt
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D003227:Conjugation, Genetic; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D006801:Humans; D010957:Plasmids; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012764:Shigella sonnei / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D015533:Transcriptional Activation; D014744:Vietnam
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin