Which organism is commonly used as an indicator for possible waterborne diseases?

Coliform bacteria are widely recognized as indicators of water quality and the potential presence of harmful pathogens in drinking water. They serve as a gauge for possible waterborne diseases because their presence suggests that other, more dangerous microorganisms may also be present. Coliforms are a group of related bacteria typically found in the environment, including in soil, vegetation, and the intestines of warm-blooded animals.

Monitoring for coliform bacteria is a standard practice in water testing because these bacteria are relatively easy to detect and can indicate fecal contamination. While specific pathogens like E. coli, Salmonella, and Enterococcus are certainly important in monitoring water safety, coliforms encompass a broader group that can signal the need for further testing for a variety of potentially harmful bacteria. Their ubiquity and the established guidelines for their detection make coliforms a practical choice for indicating the overall microbiological quality of water supplies.

Other organisms mentioned, while they indicate specific types of contamination or conditions, do not serve the same broad signaling function as coliforms, making them less effective as general indicators of possible waterborne diseases.