Enterococci are bacteria that belong to the normal large intestine flora of humans, numerous mammals as well as birds. They can cause urinary tract infections, peritonitis and rarely valvular heart disease.



Pathogen reservoir

Man, Animal, Environment

Infection route

Due to faecal contamination of water, food, etc.


If it is carried from the intestinal tract, it can lead to urinary tract infections, peritonitis and rarely - if it is washed into the bloodstream or if the heart valves are damaged - to valvulitis.


Suitable antibiotics are available


If enterococci are detectable in drinking water, disinfection of the drinking water with suitable and approved disinfectants (e.g. chlorine, chlorine dioxide, hypochlorite lye) by the drinking water supplier is required.

Situation in Austria

Enterococci are routinely analysed in drinking water, (bathing) pool water and in bathing waters. The detection of enterococci indicates with high probability a faecal contamination, therefore there is also the possibility that the water is contaminated with pathogenic microorganisms (bacteria, viruses, parasites). A parameter value (limit value) of 0 in 100 ml applies to drinking water, i.e. enterococci must not be detectable in 100 ml of water.

Drinking water test results

Technical information

Enterococci occur ubiquitously in the environment (water, soil), in animals and in humans (in the normal intestinal flora). These bacteria were first cultivated from stool samples in 1899. In food, enterococci play a role in fermentation and ripening processes (e.g. camembert and goat cheese).

Since enterococci are regularly found in the stools of humans and animals, their detection in bathing waters is also taken as an indication of faecal contamination. Faecal contamination can cause illness by introducing obligate pathogenic microorganisms (e.g. faeces of persons with hepatitis A viruses).

According to the Drinking Water Ordinance, the operator of a water supply system is obliged to inform the consumers and to point out any precautionary measures (e.g. restrictions on the use of the water or certain treatment procedures such as boiling at boiling temperature, which must be maintained for at least three minutes, if the microbiological requirements are not met). Furthermore, the purchasers must be informed that this information is to be brought to the attention of all consumers (e.g. by posting it in the building) in an appropriate manner.

After completion of disinfection, bacteriological control tests are required to verify the success of the measures taken.



Dr. Daniela Schachner

Last updated: 10.10.2023

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