What is a common indicator of fecal contamination in water?

Escherichia coli (E. coli) is widely recognized as a primary indicator of fecal contamination in water. This bacterium is commonly found in the intestines of warm-blooded organisms, including humans, making it an effective marker for the presence of fecal matter. The rationale behind using E. coli as an indicator organism is due to its ease of detection and correlation with the potential presence of pathogens that can cause waterborne illnesses.

When E. coli is detected in a water sample, it suggests that the water may have been contaminated with fecal materials, increasing the risk of harmful bacteria, viruses, and protozoa that can pose health risks to humans. Environmental authorities and health organizations often monitor E. coli levels in recreational and drinking water to assess safety for public health.

In contrast, the other organisms listed may not be as reliable as indicators for fecal contamination. While Salmonella is a pathogenic bacterium associated with foodborne illnesses, it does not solely derive from fecal matter. Vibrio cholerae is the causative agent of cholera and is also not an indicator organism for fecal contamination but rather a specific pathogen associated with certain waterborne outbreaks. Staphylococcus aureus is a common bacterium found on