title: Evaluation of the in-vitro antibacterial activity of Sch 34343.
abstract: The in-vitro activity (as measured by geometric mean MICs, mg/l) of Sch 34343 against aerobic and anaerobic bacteria was compared with that of 14 other selected beta-lactam antibiotics including aztreonam, latamoxef (moxalactam), ceftazidime and imipenem. Sch 34343 had good activity (less than 2 mg/l) against most Gram-negative aerobic bacteria whether or not they contained high levels of plasmid-mediated or chromosomally-mediated beta-lactamases. It was slightly less potent against strains of Morganella and Serratia (less than 4 mg/l) and inactive against Pseudomonas (greater than 64 mg/l). A very small inoculum effect was observed against strains containing beta-lactamases indicating stability. Unlike the third-generation cephalosporins, Sch 34343 had excellent activity (less than or equal to 0.18 mg/l) against staphylococci, comparable to that of imipenem and ampicillin. While Sch 34343 had equally good potency (0.17 mg/l) against penicillinase-positive staphylococci, it was inactive against methicillin-resistant staphylococci (greater than or equal to 35 mg/l). Sch 34343 also had good activity against streptococci. The most unusual aspect of the in-vitro activity was its activity against Bacteroides (including Bact. fragilis) and other anaerobes. Sch 34343 had mean MICs less than or equal to mg/l for all Bacteroides and Clostridium spp. tested except CI. difficile (3.4 mg/l).
mesh_terms: D000900:Anti-Bacterial Agents / Q000097:blood / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000201:enzymology; D001420:Bacteria, Aerobic / Q000187:drug effects; D001421:Bacteria, Anaerobic / Q000187:drug effects; D001798:Blood Proteins / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000201:enzymology; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006190:Haemophilus / Q000187:drug effects; D007769:Lactams; D008826:Microbial Sensitivity Tests; D009343:Neisseria / Q000187:drug effects; D011485:Protein Binding; D013291:Streptococcus / Q000187:drug effects; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D001798:Blood Proteins; D007769:Lactams; D047090:beta-Lactams; C044617:Sch 34343; D001618:beta-Lactamases