Sequential emergence of colistin and rifampicin resistance in an OXA-72- producing outbreak strain of Acinetobacter baumannii

Int J Antimicrob Agents. 2019 May;53(5):669-673. doi: 10.1016/j.ijantimicag.2019.01.012. Epub 2019 Jan 24.

Abstract

Objectives: This study reported a hospital outbreak due to an extensively drug-resistant (XDR) OXA-72-producing strain of Acinetobacter baumannii (A. baumannii).

Methods and results: The isolates were found to be genotypically indistinguishable by whole-genome multiple locus sequence typing, and to belong to the international clonal complex CC2. One of these isolates sequentially developed a high resistance to colistin and rifampicin under treatment, as a result of mutations in genes pmrB and rpoB, respectively. The blaOXA-72 gene was localised on a 10-kb transferable plasmid, named pAB-STR-1, whose sequence is nearly identical to that of another plasmid previously found in Lithuanian strains, pAB120.

Conclusion: This report highlighted the need to carefully monitor the emergence of colistin and rifampicin resistance in patients treated for infections with multidrug-resistant A. baumannii.

Keywords: Acinetobacter baumannii; Carbapenemase; Colistin resistance; Outbreak; Rifampicin resistance.

Publication types

  • Case Reports

MeSH terms

  • Acinetobacter Infections / epidemiology
  • Acinetobacter Infections / microbiology*
  • Acinetobacter baumannii / classification
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / genetics
  • Acinetobacter baumannii / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Colistin / pharmacology*
  • Conjugation, Genetic
  • Cross Infection / epidemiology
  • Cross Infection / microbiology
  • DNA-Directed RNA Polymerases / genetics
  • Disease Outbreaks
  • Drug Resistance, Bacterial*
  • Female
  • Gene Transfer, Horizontal
  • Genotype
  • Humans
  • Male
  • Molecular Typing
  • Mutation
  • Plasmids / analysis
  • Rifampin / pharmacology*
  • Sequence Analysis, DNA
  • Transcription Factors / genetics
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • PmrB protein, bacteria
  • Transcription Factors
  • DNA-Directed RNA Polymerases
  • RNA polymerase beta subunit
  • OXA-72 carbapenemase, Acinetobacter baumannii
  • beta-Lactamases
  • Rifampin
  • Colistin