[Bacteriological evaluations of combination effects with cefotiam and other antimicrobial agents against methicillin-resistant Staphylococcus aureus. I. Synergistic actions of cefotiam with imipenem and vancomycin].
We assessed the bacteriological efficacies of cefotiam (CTM) plus imipenem (IPM) and CTM plus vancomycin (VCM) therapies against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro system. The results are summarized as follows. 1. It appeared that the bacteriological efficacies of CTM+IPM therapy against MRSA strains were different against different target MRSA strains. In other words, the FIC indices of CTM+IPM were distributed in a wide range of < or = 0.5- > 2.0. The strains showing MIC levels of < or = 8 micrograms/ml in IPM concentrations showed a strong correlation with FIC index values of < or = 0.5, and the strains showing the MIC level of > or = 128 micrograms/ml in IPM concentration showed a strong correlation with FIC index values of > 2.0. Hence, the strains showing FIC indices < or = 0.5 were considered to be newborn strains with penicillin-binding protein 2' (PBP-2'), those showing FIC indices > 0.5- < or = 2.0 were considered to be strains with increasing production in PBP-2', and those showing FIC indices > 2.0 were considered to be strains with increasing productions in both PBP-2' and PBP-m2. In strains with FIC indices higher than 2.0, the 2 drugs may possibly share the action mechanism and the activity center thus they compete with each other.(ABSTRACT TRUNCATED AT 250 WORDS)
Deguchi
K
K
Section of Studies, Tokyo Clinical Research Center.
Yokota
N
N
Koguchi
M
M
Suzuki
Y
Y
Suzuki
K
K
Fukayama
S
S
Ishihara
R
R
D015310:Cefotiam / Q000494:pharmacology*; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D015378:Imipenem / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects*; D014640:Vancomycin / Q000494:pharmacology
D014640:Vancomycin; D015378:Imipenem; D015310:Cefotiam