Differential Gene Expression of Peroxide Resistant Protein (AhpC) in Planktonic and Biofilm State of Uropathogenic Escherichia coli Cells

The gastrointestinal tract seems to be the primary reservoir of Uropathogenic Escherichia coli (UPEC) in humans. UPEC strains harbor the Urinary Tract (UT) and cause Urinary Tract Infections (UTI) which might represent a serious threat to human life. To counteract with the damage caused by the Reactive Oxygen Species (ROS), bacterial strains produce various enzymes and proteins like Alkyl hydroperoxide reductase (AhpC) to scavenge the toxic oxygen molecules. The present study was designed to find the relation between the growth and biofilm formation conditions in the natural and artificial media along with the increasing resistance to the oxidative stress conditions. We studied antibacterial activity by broth dilution, antibiofilm assay, and primary adherence assay on E. coli (UPEC) (MTCC 729). Oxidative stress was studied by hydrogen peroxide assay and Lipid peroxidation assay. We further evaluated the oxidative stress by real-time PCR using alkyl hydroperoxide reductase AhpC as the gene member. Throughout the study, bacterial growth and biofilm formation were found to be more in synthetic urine. Biofilms in synthetic urine showed increased accumulation of total ROS and LPO compared to the media. From the qPCR study, we found that, when grown in the presence of favorable media, the cells showed increased gene expression. Further studies that clarify the susceptibility of strains to stress conditions and treatments need to be confirmed at the protein level.