Comparative Studies on the Survival of Indicator Organisms and Pathogens in Fresh and Sea Water

Abstract

Results are reported from a comprehensive series of experiments in which the survival characteristics of a range of indicator bacteria, pathogenic bacteria and bacteriophages was compared in fresh and seawater in the light, and at a range of temperatures, nutrient concentrations and salinities in the dark. Survival of the following organisms was studied: E.coli, faecal streptococci, maroon faecal streptococci, Salmonellatyphimurium 12, 12a and 110, S. anatum, Shigellasonnei, Sh. flexneri, Yersinia enterocolitica, Campylobacter fetus, Coliphages MS 2 and f 2. The data shows that in the light the survival of E.coli was very poor compared to that of Salmonellae. In the light, survival was best in fresh water, but in the dark survival in seawater was usually better. A linear relationship was demonstrated for T,90 and light intensity, and log T90 and temperature, but non-linear responses occurred for a range of salinities and nutrient concentrations.