Microbiological evaluation and antimicrobial resistant pattern of bacteria isolated from surface drinking water sources in Ogbomoso, Oyo State, Nigeria

Abstract

Water is vital for life, but in contrast, it might serves as the commonest route of transmission for many infectious diseases. This study was carried out to examine the quality of drinking water from two selected surface water within Ogbomoso. Water samples were collected from both water bodies at different points. Most Probable Number (MPN) techniques and pour plate method were used to estimate the bacteriological quality of water samples. The antibiotic sensitivity test was carried out on the isolated organisms, while heavy metals parameters were assessed with standard methods. Water samples were analyzed for faecal sterols. Results of MPN counts (49 to 1600 MPN per 100ml) and total heterotrophic counts (0.15×10⁶ to 1.36×10⁷ CFU/mL) revealed a high level of microbial pollution. Ten genera of bacteria; Shigella, Corynebacterium, Streptococcus, Pseudomonas, Staphylococcus, Escherichia, Salmonella, Vibrio, Citrobacter and Klebsiella were isolated and they all showed multiple antibiotic resistant (MAR) to all the antibiotics used. The multiple antibiotics resistant (MAR) index ranged from 0.63 to 0.75 and 0.63 to 0.88 for the isolates from Papa –Osiagoro and Oke- Baaki water works respectively. The heavy metals analyzed fell within the limits set by Nigerian Standards for potable waters with exception of Zn which had high concentrations across the sampling points. Water samples showed the presence of high concentrations of feacal sterols. The presence of coliforms and other pathogenic organisms present in these surface water bodies have shown that they are highly contaminated. Thus, the water is not fit for human consumption due to feacal contamination.

Keywords: Ogbomoso, Microbial pollution, Antibiotic resistance, Heavy metals, feacal sterols