title: Lack of reproducibility of macrodilution MBCs for Staphylococcus aureus.
abstract: MBCs of methicillin, oxacillin, penicillin G, cephalothin, vancomycin, and gentamicin were determined by a standard broth macrodilution technique for 101 clinical isolates of methicillin-susceptible Staphylococcus aureus. Increased killing (more than 99.9%) was observed after 48 versus 24 h of incubation for many strains, and cross tolerance to antimicrobial bactericidal activity (less than 99.9% killing) was frequently observed among antimicrobial agents. However, these in vitro measurements of bactericidal activity against S. aureus were not reproducible.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002512:Cephalothin / Q000494:pharmacology; D008712:Methicillin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000494:pharmacology; D010403:Penicillin Resistance; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D008712:Methicillin; D002512:Cephalothin; D010068:Oxacillin