Study of Antibiotic Resistance in the Fish Gut and Antibacterial Potential of Lactic acid bacteria against the isolated Multiple Drug-resistant bacteria.

The One Health approach integrates human, animal, and environmental health to address emerging diseases. Antibiotic resistance spread among microorganisms has been a concern in all ecosystems including aquatic environments. This resistance is spreading horizontally in ways that are both hidden and unfathomable. The search for alternatives is the most important need for combating the spread of antibiotic resistance. This work aims to study the spread of antibiotic resistance through horizontal transmission via plasmids and the ability of bacteria to form biofilms. In this study, a total of 31 isolates were obtained from different fishes. Cultural, microscopic, and biochemical tests were performed to identify them. The antibiotic sensitivity was performed using the disc diffusion method with Oxytetracycline, Linezolid, Vancomycin, Imipenem, Cefoxitin, Ampicillin, and Amoxicillin. Plasmid extraction and biofilm-producing capacity of the resistant isolates were studied. 67 % of isolates were found to be gram-negative and 23 % gram-positive. Antibiotic resistance profiling showed a higher percentage of resistance in gram-negative organisms with maximum resistance to Oxytetracycline. Plasmids were found in 43% of the gram-negative isolates and out of these 83% were able to form biofilms. To screen for alternatives to antibiotics, cell-free extracts of Lactic acid bacteria were tested by the agar diffusion method, and a zone of inhibition was noted. This study highlights the challenging trend of antibiotic resistance spread in aquatic ecosystems and the need for antibiotic substitutes.