Human fecal wastes harbor viral pathogens that are major infectious disease risks in drinking, recreational and shellfishing waters. Current bacterial standards for fecal coliforms, E. coli and enterococci do not reliably indicate the presence of pathogenic human viruses, and take 18-96 hours for detection. Hence, water quality managers regulate based on days old data that are not indicative of current conditions. The problems with fecal indicator bacteria can be overcome using coliphage indicators. Coliphages are viruses infecting coliform bacteria and their presence in water, wastes and shellfish indicates fecal waste presence. Researchers at UNC developed and evaluated a rapid (1-4 hour) and ultimately field-portable coliphage detection and grouping method for male specific (F+) coliphages. Rapid recovery and enrichment of coliphage by a modified version of EPA Method 1601 was followed by a 5 minute detection and serogrouping procedure of antibody-mediated particle agglutination. Low levels of F+ coliphage [between 1-5 plaque forming units (PFUs)] were first enriched to 10^7 PFU/mL to 10^9 PFU/mL in 2-3 hours. Enrichments are subjected to rapid antibody-mediated particle agglutination detection. Both MS2 reference strains and enriched MS2-like field isolates were detected by visual agglutination in ~5 minutes. For optimal binding of antibodies to particles, phosphate buffered saline (PBS) at pH 7.2 was significantly more efficient than PBS at pH 8.2 or citrate-phosphate buffer at pH 6.2 (P values <0.05). Antibody saturation of particles occurred at a dilution of <1:32 for anti-MS2 serum, corresponding to ~1 microgram of antibody protein. Antibody-mediated particle agglutination has not previously been applied to water quality monitoring, but is standard for clinical diagnostic tests in doctor’s offices because it is rapid, simple, non technical and performable under non-sterile, non-laboratory conditions. This rapid coliphage detection method using antibody-mediate particle agglutination is being developed into a simple field-portable kit, which would provide water quality managers with same-day results for decisions on advisories/closings intended to protect water users from human enteric virus exposures.

File Number: 07-0037