[Pseudomonas aeruginosa: bactericidal activity on various beta-lactam resistance phenotypes of 8 antibiotics and 7 combinations].
Bactericidal activities of 8 antibiotics (ticarcillin, piperacillin, piperacillin-tazobactam, ceftazidime, cefepime, imipenem, amikacin, ciprofloxacin) and of 7 combinations have been studied by time-killing curve technique for 16 Pseudomonas aeruginosa selected for their beta-lactams resistance phenotypes (3 wild strains, 5 penicillinases, 2 extended-spectrum beta-lactamases, 3 high level cephalosporinases and 3 non enzymatic resistance). Bactericidal activities of beta-lactams used alone were as follows: imipenem > cefepime > ceftazidime, piperacillin, piperacillin-tazobactam > ticarcillin. All the antibiotics combinations were synergistic or additive. However, only the combination of imipenem with amikacin was bactericidal for all strains. For the strains with penicillinases, piperacillin-tazobactam was not more effective than piperacillin. For the extended-spectrum beta-lactamases, we have observed a synergy with piperacillin-tazobactam and ciprofloxacin or amikacin.
Dubrous
P
P
Service de Biologie Médicale, HIA Bégin, Saint-Mandé, France.
Cavallo
J D
JD
Hernandez
E
E
Nordmann
P
P
Fabre
R
R
D000583:Amikacin / Q000008:administration & dosage / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000494:pharmacology; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D066298:In Vitro Techniques; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics; D018440:beta-Lactam Resistance; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D047090:beta-Lactams; D002939:Ciprofloxacin; D000583:Amikacin