Bacteriophages as model viruses in water quality controlag

Abstract

The potential of using bacteriophages as models for the fate of viruses in natural waters and water treatment is reviewed with special attention to the somatic coliphages, the F-specific RNA phages and phages of Bacteroides fragilis. Enumeration from highly contaminated samples can be achieved by plaque counts or enrichment methods; for less polluted samples a variety of concentration procedures is available and has been derived mainly from techniques developed for enteroviruses. International standardization of methods is necessary to promote further development of the field. Bacteriophages have promise as process indicators for viruses. F-specific RNA bacteriophages are a more homogeneous group than somatic coliphages and have generally a greater resistance. The value of somatic coliphages is further limited by their ability to multiply in unpolluted waters. Both groups are an index of sewage contamination rather than faecal contamination, hence their ecology is different from human enteric viruses. Phages of Bacteroides fragilis have been reported to occur exclusively in human faeces but little is known about their behaviour in water treatment processes.