Bacteriological pollution indicators in Ogun River flowing through Abeokuta Metropolis

Water resources are significant part of integrated community development policy and good health. Hence, the need to reduce the impact of natural and anthropogenic pollution causes so as to enhance water quality. The bacteriological quality of the Ogun River was investigated to determine the sanitary conditions of the water body between March and August, 2014. Total heterotrophic bacteria counts (THBC), total coliform counts (TCC) and total Escherichia coli counts (TEC) using standard plate count and Most Probable Number (MPN) techniques were determined. The isolates were identified using 16SrRNA gene. Total heterotrophic bacteria counts varied between 1.13 × 106 and 4.1 × 107 CFU/ml, TCC ranged between 2.5 × 105 and 2.33× 107 CFU/ml and TEC was between 5 × 104 and 1.3 × 106 CFU/ml. Most Probable Number of coliforms in all samples varied between 120 and 1600 MPN/100 ml. Isolated microorganisms include Escherichia coli strain SUS9EC, Escherichia coli O157:H7 strain SSI7, Escherichia coli strain BW25113, Escherichia coli strain C-X1B, and Klebsiella oxytoca strain KU-5. One-wayanalysis of variance showed significant difference within the samples at (P<0.05).The results revealed high bacteria counts which is higher than the recommended value of 1.2 × 102 for THBC, a zero E. coli count and not more than 10 coliforms per 100 ml by World Health Organization standards for drinking water.Keywords: Water, bacteria, Escherichia coli, pollutio