: All samples were examined for coliform and Escherichia coli counts by the five tube most probable number technique (3) and for the presence of Klebsiella sp., E. coli and Aeromonas sp. For isolation of Klebsiella sp., a loopful from each tube positive for coliforms was plated onto MacConkey agar (MA) and incubated at 37ºC overnight. For isolation of E. coli a loopful from each tube positive for E. coli was plated onto MA and incubated at 37ºC overnight.