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 1x10(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+/-15.8 h. MDA was significantly higher in group B compared to group A at 30, 60, 120 and 150 min. TAS was statistically decreased in group B compared to group A at 30 and 60 min. Increases of MDA in group B were followed by reciprocal decreases of TAS (P of correlation <0.001). Hemodynamic instability was recorded in group B compared to group A 160 min after bacterial challenge.
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.