[Antibiotic efficacies of combined uses of arbekacin and various antibiotics against methicillin-resistant Staphylococcus aureus].
Efficacies of combined uses of arbekacin(ABK) with other antibiotics against between 57 and 76 clinically isolated methicillin-resistant Staphylococcus aureus(MRSA) were examined. Other antibiotics tested were fosfomycin(FOM), 5 cephems(CEPs), 2 penicillins(PCs) and imipenem. Percentages of strains that grew at various combination of serially diluted drugs in a microdilution method were scored, and for each pair of drugs > or = MIC50 or > or = MIC90 was determined. FIC-indices were calculated at > or = MIC50. Bacterial growth was inhibited by low concentrations of ABK dose-dependently, while most of the strains tested were resistant to 9 other drugs. FIC-indices with ABK were lowest when used together with ampicillin (ABPC) (0.516) followed by combinations with cefotiam (CTM) and cefuzonam (CZON) (each, 0.53), and FOM (0.625). When combined with 0.5 microgram/ml of ABK, 0.5 microgram/ml of ABPC inhibited more than 50% of MRSA strains. CTM or CZON in combination with the same amount of ABK to 2 micrograms/ml inhibited more than 50% of MRSA. Thus ABPC was found to be the most efficient in combined use with ABK to inhibit clinical MRSA strains.
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
Oda
S
S
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D002511:Cephalosporins / Q000494:pharmacology; D003982:Dibekacin / Q000031:analogs & derivatives / Q000494:pharmacology; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D005578:Fosfomycin / Q000494:pharmacology; D015378:Imipenem / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010406:Penicillins; D005578:Fosfomycin; D003982:Dibekacin; D015378:Imipenem; C031986:arbekacin