Open AccessSurvival of Escherichia coli O157:H7 in private drinking water wells: influences of protozoan grazing and elevated copper concentrations
Author(s) -
Artz Rebekka R.E,
Killham Ken
Publication year - 2002
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2002.tb11424.x
Subject(s) - water quality , escherichia coli , biology , grazing , european union , pathogen , inoculation , zoology , microbiology and biotechnology , veterinary medicine , ecology , immunology , biochemistry , business , gene , economic policy , medicine
The survival characteristics of Escherichia coli O157:H7 in private drinking water wells were investigated to assess the potential for human exposure. A non‐toxigenic, chromosomally lux ‐marked strain of E. coli O157:H7 was inoculated into well water from four different sites in the North East of Scotland. These waters differed significantly in their heavy metal contents as well as nutrient and bacterial grazer concentrations. Grazing and other biological factors were studied using filtered (3 and 0.2 μm) and autoclaved water. The survival of E. coli O157:H7 was primarily decreased by elevated copper concentrations. This hypothesis was supported by acute toxicity assay data. In addition, significant protozoan predation effects were observed in untreated water when compared with survival rates in filtered water. The combination of these two factors in particular determines the survival time of the pathogen in a private water well. It therefore appears that wells with higher water quality as assessed using the European Union Drinking Water Directive standards will also allow survival of E. coli O157:H7 for much longer periods.