Resensitization of Multi Drug-Resistant Aeromonas caviae with Exogenous Hydrogen Sulfide Potentiated Antibiotics

Antimicrobial resistance (AMR) is a growing public health threat caused by the 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 defense mechanism against antibiotics. In this study, we isolated and identified soil-based antibiotic-resistant bacteria collected from contaminated areas. An antibiotic-resistant bacterium 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 an antibiotic-potentiator, causing bacterial membrane damage, oxidative stress, and disrupting DNA and proteins. Thus, supplying exogenous H₂S can be a good agent for the reversal of Antibiotic resistance.