Oxidative Stress in Urinary Tract Infection

Aerobic respiration and oxidation of bio molecules used as substrates, lead to production of reactive oxygen species (ROS) to combat which we have antioxidant defence mechanisms in our body. Lipid peroxidation is one of the most important expression of oxidative stress induced by ROS. Malonaldehyde (MDA), a product of lipid peroxidation along with antioxidant protein thiols are expressed in plasma. Urinary tract infections (UTIs) may appear in all age groups due to asymptomatic bacteria. The present study aims to determine the relationship of antioxidant levels and oxidative stress in UTI. 60 subjects between the age group 35- 60 years who were diagnosed with Urinary Tract Infection and attended the OPD along with 40 normal healthy subjects (as controls) were included in this study. Midstream urine was sent to microbiology laboratory for diagnosis of UTI. Macroscopic appearance of urine was also studied. MDA were assessed by thiobarbituric acid as a substrate and thiol were estimated by Ellmann's method. Data were analyzed using Statistical Package for the Social Sciences (SPSS 16). In this study we found that plasma MDA level was significantly higher and plasma thiols significantly lower in positive urine cultures compared to negative urine cultures and may indicate the existence of oxidative stress. Since MDA and protein thiols test results can be obtained before the results of cultures taken in urinary tract infection, it may be used as a diagnostic tool and may contribute to the initiation of treatment without waiting for the culture results.