title: Synergistic enhancement of in vitro antimicrobial activity of cefmetazole and cefazolin, cefotiam, cefamandole or cefoperazone in combination against methicillin-sensitive and -resistant Staphylococcus aureus. I. Effect of NaCl.
abstract: The in vitro antimicrobial activity of cephamycin, e.g. cefmetazole and cephalosporin, such as cefazolin, cefotiam, cefamandole and cefoperazone, alone and in combination, was studied employing 9 strains of methicillin-sensitive Staphylococcus aureus (MSSA) and 30 strains of methicillin-resistant Staphylococcus aureus (MRSA). Using the checkerboard agar dilution method, strong synergism was demonstrable in a majority of MSSA and MRSA strains for cefmetazole combined with these cephalosporins, with the minimum fractional inhibitory concentration index < or = 0.5. In the presence of a concentration < or = 6.25 micrograms/ml of these cephalosporins in Mueller-Hinton agar medium, the activity of cefmetazole against MRSA was most prominently potentiated by cefotiam, followed by cefamandole, cefazolin and cefoperazone. At a concentration of 12.5 micrograms/ml, cefotiam and cefamandole showed a similar effect in potentiation of cefmetazole activity. In hypertonic agar medium containing 4% NaCl, these synergistic combination effects were reduced. However, the activity of cefmetazole and cefamandole in combination under these conditions was influenced to a lesser extent and more potent than that of other combinations.
authors.affiliation: Department of Clinical Investigation, Kitano Hospital, Tazuke Kofukai Medical Research Institue, Osaka.
authors.forename: T
authors.initials: T
authors.lastname: Uete
authors.forename: K
authors.initials: K
authors.lastname: Matsuo
mesh_terms: D002435:Cefamandole / Q000008:administration & dosage*; D002437:Cefazolin / Q000008:administration & dosage*; D015311:Cefmetazole / Q000008:administration & dosage*; D002438:Cefoperazone / Q000008:administration & dosage*; D015310:Cefotiam / Q000008:administration & dosage*; D004338:Drug Combinations; D004357:Drug Synergism; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance; D012965:Sodium Chloride / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D004338:Drug Combinations; D015311:Cefmetazole; D012965:Sodium Chloride; D002435:Cefamandole; D002438:Cefoperazone; D015310:Cefotiam; D002437:Cefazolin; D008712:Methicillin