Effect of Oxidative Stress on Glutathione Reductase Activity of Escherichia coli Clinical Isolates from Patients with Urinary Tract Infection

Abstract

Background: Urinary tract infection (UTI) is frequently encountered by female population where the episode of occurrence increases with advancing age. Escherichia coli, a common UTI causing organism, retains glutathione defense mechanisms that may allow the organism to withstand host oxidative immune response as well as the harsh physiological environment of urinary tract. The aim of this study was to analyze glutathione reductase (GR) activity of UTI causing E. coli under stressful condition. Material and Methods: E. coli isolates from urine samples of UTI female patients of different ages were sampled. Samples of isolated E. coli were grown in conditions with and without oxidative stress where the stressful condition was induced by hydrogen peroxide (H2O2). In both conditions measurement of reduced glutathione level of the isolates was performed calorimetrically using microplate reader assay. Results: Samples from elderly patients showed that GSH level significantly altered, the value of GSH (mM/mg) are 5.01±0.48 and 5.20±0.64 in normal and under stressful condition respectively, which showed increase of GSH level by 3.83% (p = 0.024) under oxidative stress condition. On the other hand, in case of adult patients, GSH (mM/mg) level found to be decreased by 5.11% (p = 0.011) with the values of 5.08±0.1 and 4.82±0.18 respectively for normal and stressed condition. Conclusion: Our data suggesting an association of GR activity with patient's age, may signify that E. coli isolates respond differently to oxidative stressful environment in different age-related physiological changes and could help to uncover ways to gain better insight into E. coli pathogenesis of UTI predominance in aged population.

Ciprofloxacin-Releasing ROS-Sensitive Nanoparticles Composed of Poly(Ethylene Glycol)/Poly(D,L-lactide-co-glycolide) for Antibacterial Treatment

“…Urinary tract infections are known to induce oxidative stress and then this state aggravates the disease symptoms [ 6 , 26 ]. E. coli, a common uropathogen, responds to an oxidative stress environment according to physiological changes and the level of the anti-oxidant molecule L-glutathione (GSH) is decreased under the stress conditions [ 28 ]. This feature of UTIs can provide a targeting motive for antibiotic-incorporated nanoparticles.…”