[Comparison of four methods for the detection of fecal streptococci in water].

The objective of this study was to select an effective and fast method for the detection of socalled fecal streptococci in water by comparing a method according to the German drinking water standard, a membrane filtration method according to the ISO-draft standard 7899/2, the Chromocult Enterococcus Broth (Merck) and the Enterolert-System (IDEXX). The study was based on a collective of 297 water samples derived from different stages of water treatment and distribution, as well as from individual water supplies. The sensitivity, reliability, and selectivity of the single methods in relation to their practicability was evaluated. Concerning false positive and false negative results, the tests were proved by metabolic characterization of the isolated strains. The advantages and disadvantages of the methods resulting from the investigated criteria are discussed. The work is part of a comparative study within the scope of the DIN ad-hoc-committee "fecal streptococci".