Local Dissemination of Multidrug-Resistant Acinetobacter Baumannii Clones in a Thai Hospital

Microb Drug Resist. 2011 Mar;17(1):109-19. doi: 10.1089/mdr.2010.0062. Epub 2010 Nov 30.


A total of 83 Acinetobacter baumannii isolates from patients attending a tertiary care university hospital in Thailand were investigated for their clonal relatedness, antimicrobial susceptibility profiles, and integron carriage. Susceptibility profiles showed that 56 (67%) of these isolates exhibited multiple drug resistance (MDR). Pulsed-field gel electrophoresis (PFGE) showed that 73% of these resistant isolates were clustered into three predominant PFGE types: 6, 7, and 36. This suggested that the high number of isolates exhibiting MDR phenotypes observed in the hospital is, to some extent, due to the spread of these three resistant clones. Class 1 integrase genes were detected in all MDR isolates belonging to PFGE type 6, most MDR isolates belonging to PFGE type 7 and none of the isolates belonging to PFGE type 36. Five different class 1 gene cassette arrays, dfrA1-orfC, bla(IMP-14)-aac6', aacA4- catB8-aadA1, aacC1-orfX-orfX'-aadA1a, and aacC1-orfX-orfX-orfX'-aadA1a, were identified, of which the bla(IMP-14)-aac6' array has only been found in Thai isolates. Two isolates identified in this study carried a class 2 integrase gene with a 2.2 kb cassette array containing aadA1-sat-dfrA1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / epidemiology
  • Acinetobacter Infections / microbiology*
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / genetics
  • Acinetobacter baumannii / isolation & purification
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / genetics*
  • Child
  • Child, Preschool
  • Cloning, Molecular
  • Drug Resistance, Multiple, Bacterial / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Hospitals, University
  • Humans
  • Infant
  • Integrases / genetics
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Thailand / epidemiology
  • Young Adult


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Integrases