Survival of F-specific RNA coliphage, feline calicivirus, and Escherichia coli in water: a comparative study

Abstract

The relationship between the survival of enteric viral pathogens and their indicators (coliform bacteria and coliphages) is not well understood. We compared the survival rates of feline calicivirus (FCV), Escherichia coli, and a male-specific RNA coliphage MS2 at 4, 25, and 37 degrees C for up to 28 days in dechlorinated water. The survival rates of E. coli and FCV, a surrogate of noroviruses (NV), had a high degree of correlation at 4 and 25 degrees C, while MS2 phage survived significantly longer (P < 0.05) at these two temperatures. At 37 degrees C, the survival rates for all three organisms were highly correlated. Decimal reduction values indicating the number of days needed for 90% reduction in titer (D values) decreased for all three organisms as storage temperatures increased. FCV had the shortest D value among all three organisms at all temperatures investigated. These findings indicate that F-specific RNA phages may be useful indicators of NV in the environment.

FIG. 1.

Titers of FCV (▴), F-specific phage MS2 (•), and E. coli (▪) in dechlorinated water stored at 4, 25, or 37°C. Samples were taken at 0, 1, 2, 3, 7, 14, 21, and 28 days. The data points represent the means of the percent change in titers observed over three experimental runs.