AN OLIGONUCLEOTIDE HYBRIDIZATION ASSAY FOR THE IDENTIFICATION AND ENUMERATION OF F-SPECIFIC RNA PHAGES IN SURFACE-WATER

F-specific RNA phages can be used as model organisms for enteric virus es to monitor the effectiveness of sewage treatment, and to assess the potential contamination of surface water with these viruses. In this paper a method is described which identifies RNA phages quantitatively by a plaque hybridization assay. Oligonucleotide probes were develope d that can assign phages to their phylogenetic subgroups. Such a disti nction is important, since some subgroups preferentially occur in sewa ge of human origin, while others tend to be associated with animal was tewater. The method has been tested on a large number of isolates and represents an improvement in time and reliability over the previously used serological classification.