Hyperoxia and prolongation of aminoglycoside-induced postantibiotic effect in Pseudomonas aeruginosa: role of reactive oxygen species.
Hyperoxia prolongs the postantibiotic effect (PAE) of the aminoglycoside tobramycin in Pseudomonas aeruginosa. We tested the hypothesis that the PAE is prolonged because hyperoxia increases free radical flux while tobramycin inhibits the induction of antioxidant defenses. Exposure of P. aeruginosa to hyperoxia (100% O2) for 1 h increased superoxide dismutase, catalase, and glutathione levels. In the presence of tobramycin (1x the MIC), the induction of antioxidant defenses by hyperoxia was nearly abrogated. Neither preexposure of P. aeruginosa to hyperoxia nor supplementation with the antioxidants copper(II) (diisopropylsalicylate)2 (superoxide dismutase-like), catalase, or dimethyl sulfoxide abolished prolongation of the PAE of tobramycin induced by hyperoxia.
Park
M K
MK
Department of Pathology, School of Medicine, University of Maryland, Baltimore 21201.
Myers
R A
RA
Marzella
L
L
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D016166:Free Radical Scavengers; D010100:Oxygen / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D014031:Tobramycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D010100:Oxygen; D014031:Tobramycin