Dissemination of 16S rRNA methylase-mediated highly amikacin-resistant isolates of Klebsiella pneumoniae and Acinetobacter baumannii in Korea

Diagn Microbiol Infect Dis. 2006 Nov;56(3):305-12. doi: 10.1016/j.diagmicrobio.2006.05.002. Epub 2006 Jul 5.


Novel 16S rRNA methylase-mediated high-level resistance to amikacin and arbekacin has been reported recently in clinical isolates of Gram-negative bacilli only from several countries. We tested amikacin- or arbekacin-nonsusceptible Gram-negative bacilli isolated in 2003 and 2005 at a tertiary-care hospital in Korea by polymerase chain reaction to detect 16S rRNA methylase genes. armA alleles were detected in 14 isolates of Klebsiella pneumoniae, 10 other species of Enterobacteriaceae, and 16 Acinetobacter baumannii, whereas the rmtB allele was detected in 1 K. pneumoniae isolate. The resistance 1st detected in 2003 persisted in 2005. 16S rRNA methylase-producing isolates were highly resistant to arbekacin and amikacin, and were mostly coresistant to levofloxacin. Most K. pneumoniae isolates also produced extended-spectrum beta-lactamases and plasmid-mediated AmpC beta-lactamases, and most A. baumannii isolates were nonsusceptible to carbapenems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / drug effects
  • Acinetobacter baumannii / enzymology
  • Acinetobacter baumannii / isolation & purification*
  • Amikacin / pharmacology
  • Aminoglycosides / pharmacology*
  • Conjugation, Genetic
  • Drug Resistance, Bacterial / physiology
  • Electrophoresis, Gel, Pulsed-Field
  • Klebsiella pneumoniae / drug effects
  • Klebsiella pneumoniae / enzymology
  • Klebsiella pneumoniae / isolation & purification*
  • Korea / epidemiology
  • Methyltransferases / metabolism*
  • Microbial Sensitivity Tests
  • RNA, Ribosomal, 16S / metabolism


  • Aminoglycosides
  • RNA, Ribosomal, 16S
  • Amikacin
  • Methyltransferases
  • 16S rRNA (adenine(1518)-N(6)-adenine(1519)-N(6))-dimethyltransferase