Assessment of the sensitivity patterns of selected microorganisms isolated from the crocodile pond water at Uganda Crocs Limited, Buwama

Abstract

In veterinary medicine as well as human medicine, antimicrobial resistance has been identified as a growing global issue. The overall objective of this study was to determine the sensitivity patterns of selected microorganisms isolated from the crocodile pond water at Uganda Crocs limited, Buwama, Mpigi District. A total of 23 water samples were collected in August 2022. These samples were cultured for Escherichia coli, Salmonella spp. and Staphylococcus aureus, after which biochemical tests were carried out to confirm the species. Biochemicals tests for confirmation of E. coli included; hydrogen sulphide gas production (negative), indole (positive), motility (positive), methylene red (positive), citrate (negative) and urease (negative) and those for confirmation of Salmonella spp. included; hydrogen sulphide gas (positive), indole (negative), motility (positive), methylene red (positive), urease (negative) and citrate (negative). Out of the 23 samples; 16 samples tested positive for Salmonella spp. and 13 samples for E. coli. No sample tested positive for Staphylococcus aureus. Antimicrobial susceptibility tests on Mueller-Hinton agar were performed on all the 29 confirmed isolates using various antimicrobial agents: Ciprofloxacin, Ceftriaxone, Ampicillin, Tetracycline, Sulphamethoxazole and Gentamicin. All E. coli isolates showed no resistance to Gentamicin and Ceftriaxone, whereas, all Salmonella spp. isolates showed no resistance to Gentamicin, Ciprofloxacin, Tetracycline and Ceftriaxone. There was varying resistance to Ciprofloxacin (38.5%), Ampicillin (92.3%), Sulphamethoxazole (84.6%) and Tetracycline (84.6%) for E. coli isolates, and varying resistance to Ampicillin (75%) and Sulphamethoxazole (6.3%) for Salmonella spp. Additionally, all the 16 Salmonella spp. isolates were 100% susceptible to Gentamicin, Tetracycline and Ceftriaxone, with varying susceptibility to Ciprofloxacin (75%), Ampicillin (6.3%) and Sulphamethoxazole (93.8%). This investigation revealed that E. coli had higher rates of resistance to drug classes critical to human and animal health than Salmonella spp.