Evolution and resistance expression of MRSA. Evaluation of beta-lactam antibiotics against a set of isogenic strains with different types of phenotypic expression.
Methicillin-resistant Staphylococcus aureus (MRSA) has two mechanisms of resistance to beta-lactam antibiotics; one is mediated by mecA gene expression, and the other by penicillinase production. It has been generally accepted in the clinical field that beta-lactam antibiotics are not the drugs of choice for MRSA infection. In this report, however, ampicillin and penicillin G were shown to have relatively good activity against MRSA if combined with a beta-lactamase inhibitor, sulbactam. These beta-lactam antibiotics were found to have relatively high binding affinities to PBP2', the mecA-encoded MRSA-specific penicillin-binding protein. The possible therapeutic application of sulbactam/ampicillin against MRSA infection in combination with arbekacin, an aminoglycoside antibiotic newly developed and introduced into clinical use in Japan, is discussed.
Asada
K
K
Department of Bacteriology, Juntendo University, Tokyo, Japan.
Inaba
Y
Y
Tateda-Suzuki
E
E
Kuwahara-Arai
K
K
Ito
T
T
Hiramatsu
K
K
D000667:Ampicillin / Q000378:metabolism / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D008712:Methicillin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000378:metabolism / Q000494:pharmacology; D010405:Penicillinase / Q000235:genetics; D010641:Phenotype; D010957:Plasmids; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D000900:Anti-Bacterial Agents; D000667:Ampicillin; D010405:Penicillinase; D010400:Penicillin G; D008712:Methicillin