The study of the antibacterial efficacy and antioxidative activity mediated by exogenous Hydrogen Sulfide against Aeromonas caviae- an antibiotic-resistant organism

Abstract Antimicrobial resistance (AMR) is a growing public health threat caused by widespread overuse of antibiotics. Bacteria with antibiotic resistance may acquire resistance genes from soil or water. Endogenous hydrogen sulfide (H2S) production in bacteria confers antibiotic tolerance in many, suggesting a universal defence mechanism against antibiotics. In this study, we isolate soil-based antibiotic-resistant bacteria collected from contaminated areas. An antibiotic-resistant bacteria was identified as non-endogenous-H2S producing, allowing us to examine the effect of exogenous H2S on its resistance mechanism. Therefore, we demonstrated that different classes of antibiotic resistance can be reverted by employing H2S with antibiotics like ampicillin and gentamicin. Methods like Kirby-Bauer Disk Diffusion, Scanning Electron Microscopy and Flow Cytometer analysis were performed to assess the antibacterial activity of H2S with ampicillin and gentamicin. The antioxidative efficiency of H2S was evaluated using the DCFH-DA (ROS) test, as well as lipid peroxidation, and LDH activity. These were further confirmed with enzymatic and non-enzymatic (SOD, CAT, GST and GSH) antioxidant studies. These findings support H2S as antibiotic-potentiator, causing bacterial membrane damage, oxidative stress, and disrupting DNA and proteins. Thus, supplying exogenous H2S can be a good agent for reversal of Antibiotic resistance.