Enumeration of Escherichia coli in Water Sample

Abstract

Coliform bacteria are commonly found in soil, on vegetation, and in surface water. Escherichia coli (E. coli) is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Coliform bacteria will not likely cause illness. There are three different groups of coliform bacteria, total coliform, fecal coliform, and E. coli total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. E. coli is a sub-group of fecal coliform. Fecal coliform bacteria are a sub-group of the total coliform group. Important organisms are Salmonella, Shigella, Klebsiella, Serratia, Escherichia coli and Enterobacter aerogenes. Among these organisms, E. coli and E. aerogenes are considered fecal coliforms as they are normal inhabitants of the lower abdominal tracts of humans and animals. The presence of fecal coliform in a drinking water sample often indicates recent fecal contamination - meaning that there is a greater risk that pathogens are present than if only total coliform bacteria are detected.