Ability of azlocillin and tobramycin in combination to delay or prevent resistance development in Pseudomonas aeruginosa

• Published in: Journal of antimicrobial chemotherapy Vol. 44; no. 3; pp. 389 - 392
• Main Authors: YA LI WU, SCOTT, E. M, LI WAN PO, A, TARIQ, V. N
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-09-1999; Oxford Publishing Limited (England)
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Azlocillin - pharmacology; Biological and medical sciences; Cystic Fibrosis - microbiology; Drug Resistance, Microbial - physiology; Drug Therapy, Combination - pharmacology; Humans; Medical sciences; Microbial Sensitivity Tests; Penicillins - pharmacology; Pharmacology. Drug treatments; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - physiology; Pseudomonas Infections - microbiology; Tobramycin - pharmacology; Pseudomonadales; Drug combination; Drug susceptibility test; Enzyme; β-Lactams; β-Lactamase; In vitro; Biological activity; Prevention; Penicillin derivatives; Resistance; Antibiotic; Sensitivity resistance; Aminoglycoside; Azlocillin; Bacteria; Hydrolases; Pseudomonadaceae; Pseudomonas aeruginosa; Tobramycin; Antibacterial agent; Clinical isolate; Comparative study
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/44.3.389

The ability of combinations of azlocillin and tobramycin to prevent or delay resistance development in eight Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients was studied using chequerboard titration and in-vitro serial subculture. No isolate had developed resistance to tobramycin after 12 treatments with the antibiotic combination. Azlocillin resistance had not developed in four isolates after 16 exposures, and was delayed in the other four isolates for at least eight exposures. Beta-lactamase production was responsible for azlocillin resistance in two isolates and occurred to a lesser extent in a third.