Acinetobacter baumannii analysis by core genome multi-locus sequence typing in two hospitals in Bolivia: endemicity of international clone 7 isolates (CC25)

Int J Antimicrob Agents. 2019 Jun;53(6):844-849. doi: 10.1016/j.ijantimicag.2019.03.019. Epub 2019 Mar 27.

Abstract

In total, 95 Acinetobacter baumannii isolates recovered from patients from two hospitals in Cochabamba, Bolivia were studied. The presence of class D and B β-lactamases was investigated using polymerase chain reaction, and antimicrobial susceptibility testing was performed by agar dilution and broth microdilution. The resistance rate to carbapenems was 53.7%. All carbapenem-resistant A. baumannii (CRAb, n=51) and four carbapenem-susceptible isolates were further analysed by whole-genome sequencing. The resulting genome assemblies were used to identify the acquired resistome, and core genome multi-locus sequence typing (cgMLST) was used to determine their molecular epidemiology. All but one of the CRAb isolates (n=50) belonged to international clone (IC) 7 and they clustered into five sequence types; on cgMLST, they were found to be separated by ≥40 alleles. All CRAb isolates carried blaOXA-23 on transposon Tn2008. Metallo-β-lactamases were not detected. These data show that dissemination of several IC7 A. baumannii clones harbouring the carbapenem resistance determinant blaOXA-23 is occurring in these two hospitals in Cochambamba.

Keywords: Acinetobacter baumannii; Carbapenem-resistant; International clone 7; Tn2008; bla(OXA-23).

MeSH terms

  • Acinetobacter Infections / epidemiology*
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / classification*
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Bolivia / epidemiology
  • Cluster Analysis
  • Endemic Diseases*
  • Genome, Bacterial*
  • Genotype*
  • Hospitals
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Epidemiology
  • Multilocus Sequence Typing*
  • Polymerase Chain Reaction
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases