This document spécifiés a method for the enumeration of intestinal enterococci in water, including Enterococcus
faecalis, Enterococcus faecium, Enterococcus durans, Enterococcus avium, Enterococcus gallinarum,
Enterococcus hirae, Enterococcus casselifavus. The method is based on the growth of target organisms in a liquid
medium and calculation of the “most probable number” (MPN) of microorganisms by reference to MPN tables
or using suitable MPN informatic programs.
This method can be applied to drinking water and bathing water (fresh or marine), together with other similar
water types including those containing an appreciable amount of suspended matter, and allows the detection
of enterococci at 1 colony-forming unit (CFU) per 100 ml with définitivé results within (26 ± 2) h in the presence
of heterotrophic bacteria in numbers as high as 1 × 106 per 100 ml of sample.
For bathing waters, fresh and marine, enterococci are best enumerated when samples are diluted 1:10.
The test spécifiéd in this document relies upon the detection of intestinal enterococci based upon expression
of the enzyme ß-D-glucosidase and provides a confirméd result in 24 h without further testing of positive wells.
This document does not apply to bottled waters, for which the method has not been validated and therefore is
outside the scope of this document, unless appropriate validation of performance of this method has been
undertaken by the laboratory prior to use.