Abstract

Samples of borehole water were collected from Iperu, Ilishan, Sagamu, Ogere, Ilara, Ikenne, Irolu, Ode-remo and Babcock community, all in Ogun state. They were analyzed microbiologically using pour plate technique for total viable counts and tube fermentation technique for Most Probable Number (MPN) counts. Thirteen samples were positive for coliforms while remaining five were non-coliforms.  Three samples satisfied the W.H.O. standard requirements of coliform count between 1-3/100 ml. Four samples were suspicious having coliform count ranging from 4-8/100 ml and eleven samples with too numerous counts did not satisfy W.H.O. standard requirements. Six bacteria isolates were obtained from the samples and identified as Escherichia coli, Klebsiella sp., Proteussp., Enterobacter aerogenes, Staphylococcus aureus and Streptococcus sp. Characterization of isolates was carried out by Gram staining reaction and biochemical tests. Gram-negative bacilli (72.22%) were more prevalent in the water samples compared to Gram Positive Bacilli (11.11%) and Gram Positive Cocci (16.67%). E. coligave the highest percentage of occurrence of isolates (33.33%) followed by Klebsiella sp.(27.78%) while the percentage of occurrence of Proteus sp., S. aureus and E. aerogeneswere the least (5.56%). Two samples were confirmed for Streptococcus sp. (11.11%) andClostridium sp. (11.11%). 50% of the isolates tested positive to acid and gas.

Key words: Bacteriological analysis, water, bacteria.