Inhibition of Pseudomonas aeruginosa alginate expression by subinhibitory concentrations of antibiotics.
The effects of subinhibitory concentrations (1/4, 1/8, 1/16 of the MIC) of quinolones (ciprofloxacin, enoxacin, nalidixic acid, norfloxacin, ofloxacin, pefloxacin), aminoglycosides (amikacin, gentamicin, netilmicin, streptomycin, tobramycin), beta-lactams (aztreonam, ceftazidime, imipenem, ticarcilin) and macrolides (erythromycin, roxitromycin) on the excretion of alginate by a P. aeruginosa strain were studied. Both beta-lactam and macrolide antibiotics were found ineffective at the concentrations tested, except erythromycin and imipenem at 1/4 MIC. Aminoglycosides at a concentration of 1/4 MIC reduced most effectively the excretion of alginate. Quinolones were also effective at this sub-MIC; 1/16 MIC was ineffective with all antibiotics or stimulated the production of alginate.
Majtán
V
V
Institute of Preventive and Clinical Medicine, Bratislava, Slovak Republic.
Hybenová
D
D
D000464:Alginates / Q000378:metabolism*; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D007769:Lactams; D018942:Macrolides; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000378:metabolism*; D015363:Quinolones / Q000494:pharmacology*
D000464:Alginates; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D007769:Lactams; D018942:Macrolides; D015363:Quinolones