Faecal colibacteria
| Colibacteria are relatively
harmless microorganisms, which are present in the
intestines of humans and animals in large numbers. They play an
important role in food digestion.
Faecal colibacteria
(enterobacteriaceae) are a subgroup of colibacteria. Escherichia
coli (E. coli) is the most comminly known species of faecal
colibacterium.
Faecal colibacteria are different from other species of
colibacteria, because they grow under conditions of increased
temperature, and because they are only present in human and
animal faeces. |
Bacterial
feed with cfu coliforms |
When faecal colibacteria are present in aquatic environments,
this indicates that water is polluted by human or animal faeces.
This generally leads to the conclusion that pathogenic bacteria or
viruses are present, which come from faeces. These microorganisms
can introduce disease in humans and animals that swim in polluted
water.
Waterborne diseases linked to these microorganisms include fever,
intestinal disease and
hepatitis A.
The presence of faecal colibacteria is an indicator of a potential
health risk for swimmers. Faecal colibacteria enter surface water
sources from sewer overflows and through discharge of human and animal
waste.
Determining the amount of colibacteria in the water is carried out by
membrane filtration. Bacteria do not pass the membrane filter, and can
be separated and analyzed in the laboratory. Each separate cell develops
to a colony forming unit (cfu), and these can be counted.
Faecal streptococci
| Like colibacteria, streptococci are present in
human and animal intestines, but also in the stomach. Many
species of strepotcoccus are pathogenic. They cause diseases
such as bacterial pneumonia, ear infection and bacterial
meningitis. Faecal strepotococci (enterococcus) are a subgroup
of the genus streptococcus. Faecal streptococci can be found
within stomachs and intestines of humans and animal. They can be
distinguished because of their great resistance. |
Faecal streptococci |
Like faecal coliforms, faecal streptococci are applied
as indicators for water pollution. The presence of faecal
streptococci indicates the presence of faecal pathogens in water.
Faecal streptococci have a number of characteristics,
distinguishing them from faecal colibacteria:
- Are a less specific indicator for pathogens in faeces; because
of their great resistance they also survive on other locations besides
the stomach and intestines
- Are more suitable for food sampling than surface water sampling
- Are present in faeces in lower numbers than coliforms
- Always or almost always present in human and animal faeces;
coliforms are sometimes absent
- Incredible resistance to changing conditions
Facal colibacteria and faecal streptococci are both
parameters for the indication of clean swimming water conditions.
Sources
Omegam laboratory www.omegam.nl
Agr Belgium www.agr.kuleuven.ac.be
Faecal coliforms water quality information www.state.ky.us
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