title: In vitro activities of ureidopenicillins alone and in combination with amikacin and three cephalosporin antibiotics.
abstract: The MIC and MBC activity of mezlocillin alone and in combination with two concentrations of ceftizoxime, moxalactam, and amikacin and a single concentration of cefoxitin was studied in a broth microdilution partial checkerboard against 472 strains of aerobic gram-negative and gram-positive bacteria. Azlocillin was tested alone and in the same combinations against Pseudomonas aeruginosa. Of the gram-negative bacilli tested, 38% were gentamicin resistant. Antagonism (less than or equal to a fourfold ureidopenicillin MIC increase) was observed frequently with combinations of ureidopenicillins plus cefoxitin and sporadically with ureidopenicillins plus ceftizoxime or moxalactam. Partial synergism (less than or equal to a fourfold ureidopenicillin MIC decrease) was evident with both combinations of ureidopenicillins plus amikacin and ureidopenicillins plus ceftizoxime or moxalactam, the percentage being dependent upon the individual species and combinations.
mesh_terms: D000583:Amikacin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001390:Azlocillin / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D002511:Cephalosporins / Q000494:pharmacology*; D004347:Drug Interactions; D007612:Kanamycin / Q000031:analogs & derivatives*; D008802:Mezlocillin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010406:Penicillins; D007612:Kanamycin; D000583:Amikacin; D001390:Azlocillin; D008802:Mezlocillin