[Comparison of in vitro activities of first, second and third generation cephem antibiotics against various pathogens isolated from clinical material in 1985].

In vitro susceptibilities of 2,133 strains of various pathogens isolated from clinical materials in 1985 to various cephem antibiotics were studied using the Showa disk diffusion test. The following antibiotics were evaluated: cephalexin (CEX), cephalothin (CET), cefazolin (CEZ), cefotiam (CTM), cefoxitin (CFX), cefmetazole (CMZ), cefotaxime (CTX), cefoperazone (CPZ), ceftizoxime (CZX), cefmenoxime (CMX), latamoxef (LMOX) and cefsulodin (CFS). S. aureus: Susceptible strains to CET, CEZ, CTM, CFX and CMZ with MICs less than 15 micrograms/ml accounted for 93, 73, 94, 80 and 96% of the strains tested respectively, while those susceptible to CTX, CPZ, CZX, CMX, LMOX and CFS accounted for 91, 65, 53, 96, 65 and 95%, respectively. Susceptible strains to CEX at MICs less than or equal to 20 micrograms/ml were 52%. Prevalence of bacterial resistance to CEX and CEZ, which have been used extensively, was greater than that to CET, CTM or CMZ, showing a bimodal distribution of MICs. The third generation cephems studied, in general, also showed bimodal distributions of MICs. S. epidermidis: Susceptible strains to CET, CEZ, CTM, CMZ, CTX, CPZ and CMX with MICs less than 15 micrograms/ml were more than 82% of the strains tested. S. pyogenes: All strains studied were susceptible to CET, CEZ, CTM, CFX, CMZ, CTX, CPZ, CZX and CMX at MICs less than or equal to 15 micrograms/ml. However, susceptible strains to either LMOX or CFS accounted for 95%, while those to CEX at MICs less than or equal to 20 micrograms/ml accounted for 95%.(ABSTRACT TRUNCATED AT 250 WORDS)