2007 年 60 巻 3 号 p. 153-160
We evaluated the efficacy of cefotiam(CTM)against Staphylococcus epidermidis(S. epidermidis) isolated from blood culture and central venous catheters. Of theS. epidermidisstrains tested, 82.3% were methicillin(MPIPC)-resistant (MPIPC MIC≥0.5μ/ml) and expressed the mecA gene, and 89.2% of these MPIPC-resistant S. epdermidis(MRSE)showed less than 8.0μg/ml CTM MIC. In vitro killing kinetics of CTM against MRSE demonstrated that strains with high CTM MIC (≥4.0μg/ml) showed high MPIPC MIC (≥4.0μg/ml). All strains with low CTM MIC(≥2.0μg/ml)showed MPIPC MIC lower than 2.0μg/ml. In time-kill studies, CTM had high bactericidal activity against strains with low CTM MIC(≥2.0μg/ml), regardless of whether they were mecA positive. These results demonstrated that MRSE isolates with low CTM MIC (≥2.0μs/ml)are not easily induced CTM resistance by CTM treatment in vitro, and indicated the possibility that beta-lactams such as CTM could be an effective antibiotic agents against beta-lactamsensitive MRSE infections.
