ABUNDANCE OF BACTERIOPHAGES OF ENTERIC BACTERIA IN DIFFERENT FRESH-WATER ENVIRONMENTS

The abundances of somatic coliphages, F-specific phages and B. fragili s phages were measured in freshwater environments with different level s of faecal pollution. In samples with recent pollution of domestic or igin the numbers of the three groups of phages were highly correlated. In this set of samples d. fragilis phages were significantly outnumbe red by F-specific and these by somatic coliphages. In waters with inte rmediate levels of pollution, coliphages were more abundant than phage s infecting B. fragilis. The levels of the three groups of phages, whi ch were very low, were similar in waters with persistent faecal pollut ion indicating that B. fragilis phages were most resistant to natural inactivation processes. (C) 1997 IAWQ. Published by Elsevier Science L td.