The speciation of coliform genera from above and below a sewer outfall and their susceptibilities to antimicrobial agents.

The occurrence of coliforms in a small water course was shown to increase by a factor of thirty six below the outfall of a sewage treatment plant. Speciation of the bacteria from above and below the sewer outfall showed that Escherichia coli and Enterobacter species predominated. Drug resistance levels were significant in microorganisms from both sampling sites and the occurrence of a significant number of multiple-resistant microorganisms, particularly E. coli, is reported. Both E. coli and Enterobacter species from below the sewer outfall show a statistically significant increase in resistance to ampicillin and E. coli from below the outfall also shows a statistically significant increase in resistance to sulpha-methoxazole as compared with isolates from above the outfall.