Microbial Quality of Water and Antibiotic Susceptibility Profiles of Enteric Bacteria Isolated From Hand-Dug Wells in Sabon Gida, A Semi-Urban Nigerian Community

Abstract

In many semi-urban Nigerian communities like Sabon Gida, hand-dug wells are primary domestic water sources. However, poor sanitation and unregulated antibiotic use often compromise their safety. This study evaluated the microbial quality of water and antibiotic susceptibility profiles of enteric bacteria isolated from ten (10) hand-dug wells in Sabon Gida. Using standard microbiological techniques, Total Viable Counts (TVC), Total Coliform (TCC), and Faecal Coliform Counts (FCC) were determined. Isolates were characterized via biochemical testing, and susceptibility was assessed using the Kirby-Bauer disc diffusion method. All wells exceeded WHO and Nigerian drinking water standards. TVC ranged from 1.6 x 105 CFU/mL to 9.3 x 105 CFU/mL, while faecal coliforms (12 CFU/100mL–37 CFU/100mL) violated the zero-tolerance (0 CFU/100mL) safety threshold. Of the 23 isolates recovered, Escherichia coli was most prevalent (52.2%), followed by Klebsiella pneumoniae (34.8%) and Enterobacter aerogenes (13.0%). Susceptibility testing showed 100% resistance to Ampicillin and Tetracycline, and 91.3% to Amoxicillin/Clavulanate. Conversely, all isolates were sensitive to Gentamicin and Chloramphenicol. The presence of multi-drug resistant (MDR) enteric bacteria indicates significant faecal contamination and a high potential for waterborne disease transmission. Urgent community-wide water treatment, improved well construction, and stricter antibiotic stewardship are required to mitigate these public health risks.