Bacteriological and physico-chemical quality assessment of household drinking water in Ado-Ekiti, Nigeria

Abstract

An investigation on the bacteriological and physico-chemical properties of stored household drinking water in Ado-Ekiti, Nigeria was carried out between April and October, 2008. The drinking water sources considered for examination were harvested rain water, tap water and well water stored in plastic water pots for 2 to 4 days. The waterborne pathogens in the samples that were isolated were characterized for antibiotic resistance. Estimation of bacterial loads in the water samples revealed mean total bacterial count (TBC) of 1.17 × 105, 1.30 × 104 and 9.70 × 104 cfu/ml for rain water, tap water and well water respectively. The mean-total coliform count (TCC) were recorded as 1.57 × 106, 7.40 × 105 and 5.70 × 105 cfu/ml for rain water, tap water and well water respectively. Seven bacteria genera comprising Escherichia (41.7%), Shigella (75%), Klebsiella (33.3%), Pseudomonas (25%), Staphylococcus (25%), Streptococcus (50%) and Enterococcus (20%) were isolated from stored rain water .Three genera comprising Escherichia coli (8.3%), Staphylococcus (25%) and Pseudomonas (75%) were isolated from stored tap water. In well water samples, nine genera comprising Escherichia (50%), Salmonella (100%) Enterococcus (80%) and Shigella (25%) Proteus (100%) Serratia (100%), Klebsiella (66.6%), Staphylococcus (50%) and Streptococcus (50%) were isolated. The antibiotic susceptibility tests showed that the majority of the bacteria isolated particulaly, Escherichia, Salmonella, Enterococcus and Shigella were resistant to common antibiotics which are still available in Nigerian market. The resistance pattern of the bacterial isolates ranged from 50–100% to amoxicillin, tetracycline, streptomycin, cotrimoxazone, erythromycin, gentamicin. In terms of physico-chemical analysis, all the water samples met the WHO standard for drinking water. However, the results obtained revealed that adequate domestic water sanitation and disinfection programmes must be put in place to ensure safety against waterborne antibiotic resistant pathogens especially in developing countries.