In vitro antibacterial activity and susceptibility of cefsulodin, an antipseudomonal cephalosporin, to beta-lactamases.
Cefsulodin sodium (SCE-129, CGP-7174/E), active in minimum inhibitory concentrations (MICs) of 0.5 to 64 microgram/ml, was about 16- to 32-fold more active than carbenicillin against Psuedomonas aeruginosa. It was also active against P. diminuta, P. maltophilia, P. paucimobilis, and P. pseudoalcaligenes (MICs of 1 to 32 microgram/ml) but not against other species of Pseudomonas or other gram-negative bacteria. Except with highly carbenicillin-resistant isolates, MICs of cefsulodin for P. aeruginosa were little affected by an increase in the inoculum. With a small inoculum, minimum bactericidal concentrations (MBCs) were the same as or twice the MIC, but increasing the inoculum had a greater effect on the MBC than on the MIC. Cefsulodin was not hydrolyzed by the beta-lactamase induced in P. aeruginosa by growth in the presence of benzylpenicillin and was a poor substrate for beta-lactamases from Enterobacter cloacae and Proteus morganii. However, it was hydrolyzed, albeit slowly, by the beta-lactamase produced by most of our highly carbenicillin-resistant isolates of P. aeruginosa and by TEM-type beta-lactamases.
D001419:Bacteria / Q000187:drug effects*; D001426:Bacterial Proteins / Q000378:metabolism; D002441:Cefsulodin; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D001618:beta-Lactamases / Q000378:metabolism*
D001426:Bacterial Proteins; D002511:Cephalosporins; D001618:beta-Lactamases; D002441:Cefsulodin