CAT and bacterial vaginosis: So in comparison to healthy individuals, patients with BV may have a greater degree of oxidative stress in their vaginal discharge, as shown by a decrease in antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT), activity, and substantially increased hydrogen peroxide (H2O2) and malondialdehyde (MDA), a marker for lipid peroxidation in cells, levels [5].