Which organism is a common indicator of fecal contamination in drinking water?

C. E. coli is recognized as a standard indicator organism for fecal contamination in drinking water due to its specific association with the intestines of warm-blooded animals, including humans. Its presence serves as a reliable sign that fecal matter has contaminated the water source, as E. coli is predominantly found in the intestines and is not typically present in safe drinking water.

Utilizing E. coli as an indicator is effective because its detection suggests that pathogens harmful to human health might also be present, as these pathogens can share similar fecal origins. Moreover, E. coli testing is frequently employed because it allows for quick and relatively simple testing with established methods, facilitating rapid public health responses when contamination is suspected.

Other organisms mentioned, while impactful in their own right, do not serve the same role as E. coli for monitoring fecal contamination. For instance, while Salmonella, Vibrio cholerae, and Shigella are all significant pathogens that can contaminate water and cause illness, they do not consistently indicate fecal contamination nor are they present in water sources as frequently as E. coli. Thus, E. coli remains the go-to organism for assessing the safety of drinking water in the context of fecal contamination.