Susceptibility of anaerobic bacteria to sch

The in vitro activity of Sch 29482 (SCH) was determined against 500 isolates and compared with that of older Mactams, new parenteral Mactamase stable agents, aminoglycosides, and combination of trimethoprim and sulphamethoxazole. The compound inhibited 90 of Streptococcus pyogenes, Str. agalactiae and Str. pneumoniae at 0-2 mg1. It was as active as cephalexin, cefotaxime and ampicillin and more active than moxalactam against Gram-positive species. SCH had MIC90 values of 31 mg1 against Staphylococcus aureus. It did not inhibit methicillin resistant Staph. aureus nor Staph. epidermidis. It inhibited Mactamase-producing Haemophilus and Neisseria gonorrhoeae. The MIC90 for Klebsiella was 0-8 mg1 MIC90 for Citrobacter was 0-4 mg 1. Most Enterobacter were inhibited by 1-6 mg1, similar to the concentrations of the aminothiazolyl cephalosporins and moxalactam. MICs of Serratia ranged from 1-6 to 25 mg/1 comparable to ceftizoxime. Morganella and Providencia resistant to carbenicillin and gentamicin were inhibited. Of the Acinetobacter, 84% were inhibited, and it was more active than other agents. It did not inhibit Pseudomonas aeruginosa. Activity was minimally altered by changes in pH, type of medium, inoculum size, but was altered by serum. MIC-MBC differences were minor. SCH showed no synergy with aminoglycosides when tested against enterococci and Pseudomonas. It was not destroyed by common plasmid and chromosomal J-lactamases and it inhibited chromosomal J lactamases.