ISOLATION AND CHARACTERIZATION OF BACTERIA FROM STORAGE WATER TANKS IN FEDERAL HOUSING, GIRIE LOCAL GOVERNMENT AREA ADAMAWA STATE

ABSTRACT This study assessed the microbiological quality of drinking water from storage tanks in Federal Housing, Girei Local Government Area, Adamawa State, Nigeria. Using the spread plate method on Nutrient Agar (NA) and MacConkey Agar (MAC), total heterotrophic bacterial counts and coliform counts were determined. Results showed elevated microbial loads, with total colony counts ranging from 3.2 × 10¹ to 2.8 × 10² CFU/ml (mean: 1.17 × 10² CFU/ml) and coliform counts from 3.0 × 10¹ to 2.0 × 10² CFU/ml (mean: 7.12 × 10¹ CFU/ml). These values exceed WHO (2017) and Nigerian Standard for Drinking Water Quality (2015) guidelines, which stipulate no coliforms in 100 ml and total viable counts ≤100 CFU/ml, indicating unsafe water. Biochemical and morphological characterization identified four Gram-negative bacilli: Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Salmonella typhi, all enteric pathogens suggesting faecal contamination and inadequate sanitary barriers during storage. Antibiotic susceptibility testing against nine common antibiotics revealed significant multidrug resistance. K. pneumoniae was sensitive to amoxicillin, ofloxacin, and levofloxacin but resistant to others; S. typhi was sensitive only to amoxicillin; E. coli showed sensitivity to amoxicillin and ofloxacin; and Proteus spp. was sensitive only to gentamicin. These findings highlight the dual threat of microbial contamination and antimicrobial resistance in household water storage. Recommendations include regular tank disinfection with chlorine, stricter enforcement of water quality standards by regulatory bodies, and improved tank management practices, such as using tight-fitting covers and ensuring proper drainage to prevent faecal seepage.