Multiple Genetic Mutations Associated with Polymyxin Resistance in Acinetobacter baumannii

Antimicrob Agents Chemother. 2015 Dec;59(12):7899-902. doi: 10.1128/AAC.01884-15. Epub 2015 Oct 5.

Abstract

We studied polymyxin B resistance in 10 pairs of clinical Acinetobacter baumannii isolates, two of which had developed polymyxin B resistance in vivo. All polymyxin B-resistant isolates had lower growth rates than and substitution mutations in the lpx or pmrB gene compared to their parent isolates. There were significant differences in terms of antibiotic susceptibility and genetic determinants of resistance in A. baumannii isolates that had developed polymyxin B resistance in vivo compared to isolates that had developed polymyxin B resistance in vitro.

MeSH terms

  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / isolation & purification
  • Acyltransferases / genetics*
  • Acyltransferases / metabolism
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Drug Resistance, Multiple, Bacterial / genetics
  • Gene Expression
  • Humans
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Microbial Sensitivity Tests
  • Molecular Sequence Annotation
  • Mutation
  • Polymyxin B / pharmacology*
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • beta-Lactams / pharmacology

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Isoenzymes
  • PmrB protein, bacteria
  • Transcription Factors
  • beta-Lactams
  • Acyltransferases
  • Polymyxin B