Emergence of Carbapenem-Resistant Pseudomonas aeruginosa and Acinetobacter baumannii Clinical Isolates Collected from Some Libyan Hospitals

Microb Drug Resist. 2015 Jun;21(3):335-41. doi: 10.1089/mdr.2014.0235. Epub 2015 Jan 14.

Abstract

The aim of the present study was to investigate the molecular mechanism of carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates recovered from Libyan hospitals between April 2013 and April 2014. In total, 49 strains (24 P. aeruginosa and 25 A. baumannii) were isolated, including 21 P. aeruginosa and 22 A. baumannii isolates (87.75%) resistant to imipenem (minimum inhibitory concentrations ≥16 μg/ml). The blaVIM-2 gene was detected in 19 P. aeruginosa isolates. All imipenem-resistant P. aeruginosa isolates showed the presence of OprD mutations. Acquired OXA-carbapenemase-encoding genes were present in all A. baumannii isolates: blaOXA-23 (n=19) and blaOXA-24 (n=3). Finally, a total of 13 and 17 different sequence types were assigned to the 21 P. aeruginosa and the 22 A. baumannii carbapenem-resistant isolates, respectively. This study is the first report describing imipenem-resistant P. aeruginosa and A. baumannii isolated from patients in Libya. We report the first case of co-occurrence of blaVIM-2 with oprD porin loss in identical isolates of P. aeruginosa in Libya and demonstrate that these oprD mutations can be used as a tool to study the clonality in P. aeruginosa isolates. We also report the first identification of multidrug-resistant A. baumannii isolates harboring blaOXA-23-like, blaOXA-24-like, and blaOXA-48-like genes in Libya.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / epidemiology*
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / classification
  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / isolation & purification
  • Anti-Bacterial Agents / pharmacology
  • Gene Expression Regulation, Bacterial*
  • Hospitals
  • Humans
  • Imipenem / pharmacology
  • Libya / epidemiology
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Mutation
  • Phylogeny
  • Plasmids / chemistry
  • Plasmids / genetics
  • Plasmids / metabolism
  • Porins / genetics*
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / epidemiology*
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / classification
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / isolation & purification
  • beta-Lactam Resistance / genetics
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Porins
  • OprD protein, Pseudomonas aeruginosa
  • Imipenem
  • beta-Lactamases