1986 Volume 34 Issue 8 Pages 672-676
Ninety-six Staphylococcus aureus strains were isolated from septicemic patients at the Tokyo Metropolitan Geriatric Hospital and their in vitro antimicrobial susceptibility to 9 β-lactam antibiotics was examined. Twenty-five% of the isolates were not inhibited by methicillin at a concentration of 6.25μg/ml. All of these methicillin-resistant strains possessed inducible penicillinase activity.
Most drugs showed strong antibacterial activity against 96 S. aureus strains. Especially, imipenem was found to be most active and was followed by cephaloridine, SCH 34343, L-105, and HR 810, in that order.
Pathogenicity of these strains toward mice was examined, indicating that there were no Smith-like strains possessing high pathogenic to mice among the isolates. Especially, it was found that the highly methicillin-resistant (≥200μg/ml) strains didn't show any pathogenicity toward mice, when infected with saline suspension (O.5 ml) of 108 cells/ml of these strains.
