Genetic characterisation of drug resistance and clonal dynamics of Acinetobacter baumannii in a hospital setting in Mexico

Int J Antimicrob Agents. 2015 Mar;45(3):309-13. doi: 10.1016/j.ijantimicag.2014.10.022. Epub 2014 Dec 5.

Abstract

The aim of this study was to determine the clinical characteristics, molecular epidemiology and biofilm production of Acinetobacter baumannii clinical isolates obtained from a tertiary-care hospital in Mexico. Clinical isolates of A. baumannii (n=152) isolated from 2007 to 2012 were included. Clonal diversity was analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antimicrobial susceptibility was determined using the broth microdilution method. IMP, VIM, NDM and OXA-type genes were screened by PCR. Biofilm production was analysed using the crystal violet method. Mortality attributable to A. baumannii infection was 14.5%. Fifty-four clones were detected, of which five predominated. MLST results showed three new sequence types and two reported sequence types. More than 86% of the isolates were resistant to ciprofloxacin, ceftazidime and cefotaxime. Furthermore, 50.7% and 35.5% of the isolates were resistant to imipenem and meropenem, respectively. Of the isolates evaluated, 28.3% and 25.7% were positive for the blaOXA-58 and blaOXA-72 genes, respectively. Biofilm production was associated with resistance to imipenem (P=0.002).

Keywords: Acinetobacter; Biofilm; Carbapenemases; OXA-58; OXA-72; PFGE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / epidemiology
  • Acinetobacter Infections / microbiology*
  • Acinetobacter Infections / mortality
  • Acinetobacter baumannii / classification*
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / isolation & purification
  • Acinetobacter baumannii / physiology
  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Biofilms / growth & development
  • Cross Infection / epidemiology
  • Cross Infection / microbiology*
  • Cross Infection / mortality
  • Drug Resistance, Bacterial*
  • Female
  • Genotype
  • Hospitals
  • Humans
  • Male
  • Mexico / epidemiology
  • Microbial Sensitivity Tests
  • Middle Aged
  • Molecular Epidemiology
  • Molecular Typing*
  • Survival Analysis
  • beta-Lactamases / genetics

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases