Oxidative stress–induced alterations in enzymatic balance of Salmonella Enterica

The action of oxidative stress on the enzymatic balance of antioxidants in Salmonella Enterica clinical isolates was investigated in this study. In 2025, 20 isolates were gathered in clinical samples in Kirkuk, during the period of between February and October and identified using colony morphology, Gram staining, and routine biochemical tests. Oxidative stress was induced by introducing bacterial cultures in the logarithmic growth phase to different concentrations of hydrogen peroxide (0.5, 1 and 2 mM). SOD, catalase (CAT), and peroxidase (POD) activities in cell extracts were determined using a spectrophotometer, and they were adjusted to the protein content of the extracts. The outcomes revealed a significant, concentration-related enhancement in all the antioxidant enzyme activities over untreated controls with SOD displaying the best response succeeding by CAT and POD. These results suggest that S. enterica triggers the induction of a coordinated enzymatic defense mechanism to alleviate oxidative stress, and thus its adaptive responses to survive during stressful environments. The knowledge of such responses could help in the establishment of counter-measures that could aim at overcoming bacterial antioxidant defense in aid of antimicrobial activity.