ANTIBIOGRAM PROFILE OF BACTERIA ISOLATED FROM WUPA SEWAGE TREATMENT PLANT (WSTP), ABUJA

Abstract

The presence of antimicrobial-resistant bacteria in municipal sewage treatment plants (STPs) has raised concerns regarding the potential dissemination of resistant strains into the environment. This study aimed to characterize the antibiogram of bacteria isolated from the Wupa sewage treatment plant (WSTP). Thus, providing insights into the prevalence and resistance patterns of these bacteria species. Physicochemical and Microbiological properties of the homogenized sludge were determined by qualitative techniques and subsequent biochemical tests were used to identify the isolates. The antibiotic susceptibility profiles of the isolates were determined using the Modified Kirby-Bauer disc diffusion technique. The physicochemical analyses of the sludge sample revealed characteristics typical of organic waste material as it showed high moisture content (88.7±2.3%), slightly basic pH (6.86±0.22), and a significant presence of organic matter (37.48±4.2%). The total heterotrophic bacterial counts, total coliform counts, and faecal coliform counts of the sludge sample were 6.08±2.2x10⁶ cfu/g, 1.76±0.2x10⁶ cfu/g, and 3.0 x 10⁵ ±0.8 cfu/g respectively, the total Salmonella-Shigella counts and total Staphylococcus counts were 3.2±0.4x10⁵ cfu/g and 4.3±0.3x10⁵ cfu/g respectively, the total Pseudomonas count was 1.4±0.1x10⁵ cfu/g. Fourteen (14) bacterial genera comprising, Staphylococcus, Enterobacter, Bacillus, Streptococcus, Escherichia, Shigella, Pseudomonas, and Salmonella were isolated. The bacterial isolates were highly resistant (<14mm) to Amoxicillin-Clavulanic and Cefuroxime, while susceptibilities (≥20mm) to Ofloxacin and Gentamicin were observed among the isolates. The results revealed a diverse array of bacterial species with varying susceptibility patterns to antimicrobial agents, highlighting the need for effective wastewater management strategies to mitigate potential public health and environmental risks.