Emergence and spread of carbapenem-resistant Acinetobacter baumannii in a tertiary care hospital in Turkey

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Meric M., KASAP M. , GACAR G. , BUDAK F. , DÜNDAR D. , KOLAYLI F. , ...More

FEMS MICROBIOLOGY LETTERS, vol.282, no.2, pp.214-218, 2008 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 282 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1111/j.1574-6968.2008.01129.x
  • Page Numbers: pp.214-218
  • Keywords: Acinetobacter infections, carbapenems, antibiotic resistance, beta-lactamases, BETA-LACTAMASES, NOSOCOMIAL INFECTIONS, GENE, EXPRESSION, IDENTIFICATION, OUTBREAK, PREVALENCE, OXA-23, SPP.


An intensive care unit (ICU)-based OXA-23-producing multiple-drug resistant Acinetobacter baumannii (MDRAB) outbreak was detected between October 2005 and October 2006. A total of 47 patients were infected/colonized with the outbreak strain. Clinical data were available from 37 patients. The all-cause mortality rate among the patients exposed to the epidemic strain was 35% (13/37). The outbreak strain and the resistance determinants were characterized both by microbiological methods and by molecular techniques. Cloning and sequencing experiments identified ISAbaI-associated bla(oxa-23) on the chromosome. Screening of imipenem-resistant Acinetobacter isolated from the ICU during the outbreak period with PCR identified 97 isolates as positive for the ISAbaI-bla(oxa-23) structure. Pulsed-field gel electrophoresis and plasmid analyses with selected nonrepetitive isolates revealed the clonality. Disk diffusion on cloxacillin-supplemented agar media and the real-time PCR experiments showed that outbreak isolates are overexpressing the ampC enzyme. This study highlights the occurrence of OXA-23-producing and ampC-overexpressing MDRAB in ICUs.