A rapid method for detecting enterococci in real water samples

Waterborne diseases remain a significant cause of illness and mortality in both developing and developed countries. Contaminated water, especially water containing fecal matter, serves as a reservoir for various pathogens. However, the identification and monitoring of all pathogens in water are often hindered by limitations in time, resources, and the complex ecology of microbial communities. To overcome these challenges, indicator bacteria are widely used as proxies to assess the presence of pathogenic bacteria and fecal contamination in water. Among these indicators, enterococci, commonly found in the intestinal microflora of humans and animals, are extensively used due to their abundance in contaminated water. Their presence serves as an effective marker for water quality assessment. In this study, we developed a simple, rapid, and cost-effective lateral flow assay (LFA) for detecting enterococci in environmental water samples. The LFA utilizes antibody-antigen interactions between gold nanoparticle-conjugated Enterococcus antibodies and enterococci, enabling detection within minutes. The assay's specificity was validated by distinguishing enterococci in the presence of Escherichia coli and Shigella sonnei. Additionally, the LFA demonstrated reliable detection of enterococci in both freshwater and seawater samples, achieving performance comparable to conventional viable plate counting methods. These findings suggest that the LFA is a rapid, user-friendly, and cost-effective tool for on-site and real-time monitoring of enterococci in environmental waters, providing a valuable method for enhancing water quality surveillance and public health protection.