The significance of oxidant/antioxidant balance for the pathogenesis of experimental sepsis by multidrug-resistant Pseudomonas aeruginosa

Abstract Objective : The significance of lipid peroxidation as an independent factor leading to sepsis by multidrug-resistant Pseudomonas aeruginosa . Design experimental study Methods : Twenty-six rabbits were applied. They were divided into two groups; A ( n = 6 ) comprising controls, and B ( n = 20 ) comprising animals infected by the injection of 1×10 8 cfu/kg inoculum of the test pathogen into the left inner jugular vein. Six rabbits of group B were followed-up to estimate survival; all of the remaining were sacrificed. Blood was sampled for the determination of serum malondialdehyde (MDA) by the thiobarbiturate assay, total antioxidant status (TAS) by a chromogenic assay, tumor necrosis factor alpha by a bioassay on fibrosarcoma L929 cell line, and endotoxins (LPS) by the QCL-1000 LAL assay. Results : Mean survival of group B was 60.0±15.8h. MDA was significantly higher in group B compared to group A at 30, 60, 120 and 150min. TAS was statistically decreased in group B compared to group A at 30 and 60min. Increases of MDA in group B were followed by reciprocal decreases of TAS ( P of correlation Conclusions : Early alterations of oxidant/antioxidant balance occur in experimental sepsis by multidrug-resistant P. aeruginosa followed by hemodynamic instability. Results highlight the perspective of the administration of antioxidants as immunomodulatory treatment of sepsis in animal studies.