Distinct Antimicrobial Resistance Patterns and Antimicrobial Resistance-Harboring Genes According to Genomic Species of Acinetobacter Isolates

Abstract

ABSTRACT Using 58 isolates of Acinetobacter species recovered from a university hospital between August 2004 and March 2005, we performed genomic identification by amplified rRNA gene restriction analysis (ARDRA) and investigated the existence of metallo-β-lactamase (MBL) producers and extended-spectrum β-lactamase (ESBL) producers. Genomic species identification of Acinetobacter strains using ARDRA showed that 40 strains were genomic species 2 ( Acinetobacter baumannii ), 9 were 13 sensu Tjernberg and Ursing (13TU), 5 were Acinetobacter phenon 6/ct 13TU, and 4 were Acinetobacter genospecies 3. Among 58 strains, 13 isolates were MBL producers carrying bla IMP-1 or bla VIM-2 and 13 isolates were ESBL producers carrying bla PER-1 . Notably, the MBL producers were mostly 13TU, Acinetobacter phenon 6/ct 13TU, and Acinetobacter genospecies 3, which showed susceptibility to ciprofloxacin and ampicillin-sulbactam. However, 12 of 13 strains carrying bla PER-1 were A. baumannii , showing multidrug resistance. The data revealed that the antimicrobial resistance patterns and resistance-harboring genes of Acinetobacter species are remarkably distinct according to the genomic species of Acinetobacter isolates.