COMPARATIVE STUDY OF METHODS FOR ASSESSING ESCHERICHIA COLI SPECIES IN DRINKING WATER

Abstract

The study on drinking water quality is a priority for the health of consumers, the absence of pathogenic microorganisms is a prerequisite for compliance with EU Directive. Coliforms, fecal coliforms and Escherichia coli are used as indicators of fecal contamination of water supplies and recreational waters.The most important bacteriological condition for drinking water is the total absence of pathogenic microorganisms. The measurement of bacteria of the coliform group has been used extensively as an indicator of water quality.Given the relatively laborious methods of recognizing their presence and the inconsistent nature of that presence in water, the Escherichia coli level is analysed. The purpose of this study is to analyze comparatively two methods for determining the Escherichia coli species in drinking water of the drinking water supply network of Suceava city and that of own resources within Suceava county area. The analysis results of water samples studied by the two methods show that the membrane filtration method favours a specific growth and selective Escherichia coli species, compared with the multiple-tube method. Membrane filtration method is recommended for effective monitoring of drinking water contamination in terms of Escherichia coli species. Multiple-tube method is a method applicable to all types of water, and equipment is relatively inexpensive and less specialized.