title: [In vitro activity of arbekacin against clinical isolates of Staphylococcus species and gram-negative bacilli].
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) and some gram-negative bacilli are very prevalent nosocomial pathogens, commonly causing mixed infections, and are often resistant to multiple drugs. Arbekacin is an aminoglycoside used for the treatment of MRSA infections, but is also active against some gram-negative bacilli. The aim of this study was to determine in vitro activity of arbekacin against recent clinical isolates of staphylococci and gram-negative bacilli.
  
  
  METHODS
  The strains were isolated from clinical specimens of patients at Severance Hospital in 2003. Antimicrobial susceptibility was tested by the Clinical and Laboratory Standards Institute agar dilution method. The following arbekacin breakpoints were used: susceptible, </=4 microg/mL; and resistant, >/=16 microg/mL .
  
  
  RESULTS
  All isolates of staphylococci tested were inhibited by </=4 microg/mL of arbekacin, regardless of their methicillin susceptibility. The MIC90s of arbekacin, 1-4 microg/mL, were 8->32-fold and >32-128-fold lower than those of amikacin and gentamicin, respectively. The resistance rates of MRSA, methicillin-susceptible S. aureus, methicillin-resistant coagulase-negative staphylococci (CNS) and methicillin-susceptible CNS were 0% to arbekacin, 0-54% to amikacin, and 24-79% to gentamicin. The MIC90s of arbekacin for Escherichia coli and Citrobacter freundii, 1 microg/mL and 16 microg/mL, were 2-4-fold and 8-16-fold lower than those of amikacin and gentamicin, respectively. However, The MIC90s of arbekacin for other species of gram-negative bacilli, 64->128 microg/mL, were similar to those of other aminoglycosides.
  
  
  CONCLUSIONS
  Arbekacin may be a useful alternative to glycopeptides for the treatment of monomicrobial methicillin-resistant staphylococcal infections, as well as mixed infections with gram-negative bacilli, as most isolates of E. coli, C. freundii and some other gram-negative bacilli were also susceptible to arbekacin.
authors: Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors: Jonghan
authors: J
authors: Lee
authors: Chang Ki
authors: CK
authors: Kim
authors: Kyoung Ho
authors: KH
authors: Roh
authors: Hyukmin
authors: H
authors: Lee
authors: Jong Hwa
authors: JH
authors: Yum
authors: Dongeun
authors: D
authors: Yong
authors: Kyungwon
authors: K
authors: Lee
authors: Yunsop
authors: Y
authors: Chong
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003982:Dibekacin / Q000031:analogs & derivatives* / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D003982:Dibekacin; C031986:arbekacin