title: In vitro activity and beta-lactamase stability of BL-S786 compared with those of other cephalosporins.
abstract: In vitro activity of BL-S786, a new parenterally semisynthetic cephalosporin, was investigated against 570 bacterial isolates. BL-S786 inhibited most Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella. It inhibited some Enterobacter and indole-positive Proteus, but it was less active against these later species than was cefamandole, cefuroxime, or cefoxitin. It was not active against Serratia marcescens, Pseudomonas aeruginosa, or Bacteroides fragilis. BL-S786 was the least active new cephalosporin tested against staphylococci and was less active than cephalothin against streptococcal species. The activity of BL-S786 was not altered by the type of assay medium nor by 50% serum. The size of the test inoculum altered the minimal inhibitory and bactericidal concentrations for inhibition of some organisms, particularly those with Richmond type I beta-lactamases. BL-S786 was not hydrolyzed by the R-factor-mediated, Richmond type III beta-lactamase, but it was hydrolyzed by type I beta-lactamases.
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects*; D002510:Cephalosporinase / Q000378:metabolism*; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology*; D004355:Drug Stability; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests
chemical_list: D002511:Cephalosporins; D000581:Amidohydrolases; D002510:Cephalosporinase