[Comparison of in vitro activity of first, second and third generation cephem antibiotics against various pathogens isolated from clinical materials in 1983].
In vitro susceptibilities of 3,286 strains of various pathogens isolated from clinical materials in 1983 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) and latamoxef (LMOX). S. aureus: Susceptible strains to CET, CEZ, CTM, CFX and CMZ with MIC less than 15 micrograms/ml accounted for 93, 75, 93, 70 and 96% of the strains tested, while those to CTX, CPZ, CZX, CMX and LMOX for 89, 65, 61, 86 and 62%, respectively. Susceptible strains to CEX at MICs less than or equal to 20 micrograms/ml were 60%. 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. pyogenes: All strains studied were susceptible to CET, CTX, CPZ, CZX, CMX and LMOX at MICs less than or equal to 15 micrograms/ml. However, susceptible strains to CEZ, CTM, CFX and CMZ accounted for 95, 95, 80 and 90%, respectively, while those to CEX at MICs less than or equal to 20 micrograms/ml for 79%. S. pneumoniae: At MICs less than 3 micrograms/ml, all strains were susceptible to all cephem antibiotics tested. S. faecalis: Only a very few strains were susceptible to these antibiotics. E. coli, K. pneumoniae and Proteus spp.: Susceptible strains of E. coli and K. pneumoniae to CEX at MICs less than or equal to 20 micrograms/ml accounted for 80 and 81% of the strains tested, while those of indole negative and positive Proteus for 69 and 4%, respectively. Strains of E. coli susceptible to CET, CEZ, CTM, CFX and CMZ at MICs less than or equal to 15 micrograms/ml were 78 to 96%, while those to CTX, CPZ, CZX, CMX and LMOX were 94 to 100%. Those of K. pneumoniae to these 2 groups of antibiotics were 81 to 95% and 94 to 100%, respectively. Susceptible strains of indole negative Proteus to the former group were 81 to 93% and those to the latter were 100%.(ABSTRACT TRUNCATED AT 400 WORDS)
D002437:Cefazolin / Q000494:pharmacology; D015311:Cefmetazole; D002506:Cephalexin / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology*; D002513:Cephamycins / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D009070:Moxalactam / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects; D013297:Streptococcus pyogenes / Q000187:drug effects
D002511:Cephalosporins; D002513:Cephamycins; D015311:Cefmetazole; D002437:Cefazolin; D002506:Cephalexin; D009070:Moxalactam