Interactions between methicillin and vancomycin in methicillin-resistant Staphylococcus aureus strains displaying different phenotypes of vancomycin susceptibility.
Vancomycin-sensitive, -intermediate, and -heterointermediate methicillin-resistant Staphylococcus aureus isolates were tested by using E-tests to explore the interaction of methicillin and vancomycin. For the vancomycin-intermediate and -heterointermediate strains both drugs showed antagonism at concentrations below their MICs but synergy at methicillin concentrations near the MIC. This property could be used to screen for heterointermediate S. aureus strains.
Howe
R A
RA
Bristol Centre for Antimicrobial Research and Evaluation, Department of Medical Microbiology, Southmead Health Services NHS Trust, Westbury-on-Trym, Bristol BS10 5NB, United Kingdom.
Wootton
M
M
Bennett
P M
PM
MacGowan
A P
AP
Walsh
T R
TR
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004347:Drug Interactions; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000494:pharmacology*; D010641:Phenotype; D013211:Staphylococcus aureus / Q000187:drug effects*; D014640:Vancomycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010406:Penicillins; D014640:Vancomycin; D008712:Methicillin