Combination effect of vancomycin and beta-lactams against a Staphylococcus aureus strain, Mu3, with heterogeneous resistance to vancomycin.
We tested the combined activity of vancomycin and seven beta-lactam antibiotics against Staphylococcus aureus clinical strain Mu3, which displays heterogeneous resistance to vancomycin. When combined with vancomycin, four of the seven tested beta-lactams exhibited an additive effect at or near their MICs, while all showed an antagonistic effect at lower, sub-MIC levels. This study implicated the unpredictable nature of combination therapy of beta-lactams and vancomycin against S. aureus with reduced susceptibility to vancomycin.
Department of Bacteriology, Juntendo University, Tokyo, Japan.
N
N
Aritaka
H
H
Hanaki
L
L
Cui
K
K
Hiramatsu
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D004347:Drug Interactions; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010457:Peptidoglycan / Q000096:biosynthesis; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000378:metabolism; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance; D047090:beta-Lactams / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010457:Peptidoglycan; D047090:beta-Lactams; D014640:Vancomycin