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
Uete, T.; Matsuo, K.
Japanese Journal of Antibiotics 48(4): 553-562
1995
ISSN/ISBN: 0368-2781 PMID: 7783318 Document Number: 453805
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.