The effect of environmental factors on coliphages in the Welsh River Dee

Abstract

In a l‐year study at Ironbridge on the Welsh River Dee the Escherichia coli popu‐lation varied over a 200‐fold range and the coliphage populations grown at 37°C (H. T. phage) and at 22°C (L. T. phage) each varied by over 100‐fold. Both the E. coli and H. T. phage counts were shown to have highly signiflcant seasonal fluctuations, which included troughs in summer and peaks in winter. The L. T. phage count appeared to maintain a baseline population in summer and had a 20‐fold less sig‐nificant association with temperature than the H. T. phage population.

Annual variation and reliability of fecal indicators in a polluted river

“…The concentrations of coliphages in the river Vantaanjoki watercourse were high in winter and low in summer, as was also observed in the river Danube (Simkova and Cervenka, 1981). Our study confirms the seasonal variation of E. coli and high-temperature coliphages observed in the River Dee in Wales (Nuttal and Parry, 1987). Some of the correlations between chemical water quality variables and E. coli and coliphages were the same in this study as in that of Nuttal and Parry, although some were reversed.…”

A method for the direct isolation of IncH plasmid-dependent bacteriophages

“…Plaque formation by IncH-dependent phages was shown to be temperature-sensitive; all 27 phages failed to produce plaques above 30°C. A number of previous studies have shown the presence of temperature-sensitive coliphages in sewage-contaminated water (Seeley & Primrose 1980;Nuttall & Parry 1987) but plasmid dependence was not determined.…”

“…The discovery of these R-factors suggests that environmental R-factor transfer may have epidemiological significance (Maher & Colleran 1987). Thermosensitive coliphages have also been isolated from the environment (Seeley & Primrose 1980) and there is evidence that they can multiply in river water (Nuttall & Parry 1987). In this study we describe a method for the direct isolation from sewage of temperaturesensitive coliphages that are IncH plasmiddependent.…”