title: In vitro activity against aerobic and anaerobic gram-positive and gram-negative bacteria and beta-lactamase stability of RS-533, a novel carbapenem.
abstract: RS-533 is a novel carbapenem antibiotic. Its activity was compared with that of imipenem and the new cephalosporins, aztreonam, piperacillin, and tobramycin. RS-533 had activity comparable to that of imipenem, inhibiting the majority of the Enterobacteriaceae, streptococci, staphylococci, and Bacteroides species at concentrations of less than or equal to 2 micrograms/ml. RS-533 inhibited Enterobacter cloacae, Citrobacter freundii, and Serratia marcescens resistant to ceftazidime, aztreonam, and cefoperazone, but RS-533 did not inhibit all methicillin-resistant Staphylococcus aureus or Pseudomonas maltophilia. It inhibited tobramycin-resistant members of the Enterobacteriaceae and Pseudomonas aeruginosa. RS-533 was stable against attack by common chromosomal and plasmid-mediated beta-lactamases and was an effective inhibitor of many beta-lactamases.
mesh_terms: D001398:Aztreonam / Q000494:pharmacology; D002438:Cefoperazone / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D002440:Cefoxitin / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D015378:Imipenem; D008826:Microbial Sensitivity Tests; D010878:Piperacillin / Q000494:pharmacology; D013845:Thienamycins / Q000494:pharmacology*; D014031:Tobramycin / Q000494:pharmacology; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D013845:Thienamycins; D065093:beta-Lactamase Inhibitors; D002440:Cefoxitin; D015378:Imipenem; D002438:Cefoperazone; D002442:Ceftazidime; D001618:beta-Lactamases; D001398:Aztreonam; D002439:Cefotaxime; D014031:Tobramycin; C039536:panipenem; D010878:Piperacillin