Bacteriological quality assessment of two sources of water supplies in Mubi, North-eastern Nigeria

Water is essential for all life forms and the provision of safe drinking water to the populace cannot be overemphasized. This study examined the bacteriological quality of two sources of water supplies in Mubi, North-eastern Nigeria. A total of 72 water samples were analysed. These include 30 from 10 brands of sachet water and 42 from 21 boreholes in seven different wards of Mubi. Heterotrophic plate count (HPC) was determined by pour plate technique and the total coliform count was determined by 3-3-3 regimen using most probable number (MPN) technique. Escherichia coli and other isolates were identified by standard protocols. The mean HPC for both borehole and sachet water samples were variable and ranged from 3.3 × 102 – 4.7 × 104 cfu/ml for sachet water and 1.1 – 6.0 × 104 cfu/ml for borehole water samples. The HPC of borehole water samples were significantly higher than those of sachet water (P = 0.006). The results showed that the mean MPN index for sachet water samples from brand HCM, KGN, OYM and YNS were zero (0). Brand UDS had the highest mean MPN index (1966.7), while other brands had low mean MPN index that ranged from 3.0 -9.1. In the same vein, the mean MPN index of borehole water samples were high, variable and ranged from 3.7 – 1750. Statistically, the mean MPN index/100ml of borehole water samples were significantly higher than those of sachet water samples (P = 0.006). A total of 49 non-repetitive bacterial species were isolated from the two sources of water. These include E. coli (30), Enterobacter spp (3), P. aeruginosa (5) and Citrobacter spp (11). The distributions of bacterial isolates from the two sources of water showed that E. coli was detected in two brands of sachet water SDK and DYJ and 20 representative boreholes in all the locations, while other organisms were variably distributed. The presence of these organisms constitutes public health significance.