E. coli is a pathogenic bacteria found in the digestive tract of humans and animals. It can enter drinking water sources through failing septic tanks, leaky sewer lines, wastewater treatment plants, stormwater runoff, and animal sources like manure and livestock waste. The presence of E. coli in drinking water indicates contamination and can cause abdominal cramps, diarrhea, and cellular dysfunction in humans. There are several categories of E. coli that differ in their pathogenic traits.

1. Escherichia coli
Anup Ghimire, Rock Face Limited

2. Common Microbes in
Drinking Water
• Cryptosporidium
• Anabaena species
• Copepods
• Rotifers
• E. coli
• Rhizopus stolinifer
• Naegteria fowleri
• Legionella Pneumophila
• Chaetomium species
• Salmonella Enterica

3. E. Coli
• Pathogenic bacteria found in the digestive tract of human
and animal.
• Sub group of faecal coliform bacteria

4. Sources in drinking water
Human induced sources
• Failing septic tanks,
• leaking sewer lines
• wastewater treatment plants
• combined sewer overflow (CSOs)
• urban storm water runoff

5. …sources in drinking
water
Animal sources
• Manure spread on land
• Livestock in runoff or in streams
• Improperly disposed farm animal wastes
• Pet and bird wastes

6. Coliform Test
• Biological quality tested by total coliform test
• Absence of coliform bacteria: safe drinking water
• Presence of coliform bacteria: contaminated water

7. Health Effects
• Abdominal cramps and diarrhoea
• Cellular function such as protein synthesis, mitochondrial
function, cytoskeletal function, cell division, ion
secretion, transcription and apoptosis.

8. Categories of E. coli
• enteropathogenic E.coli (EPEC)
• entrohaemorrhagic E. coli (EHEC)
• enterotoxigenic E. coli (ETEC)
• enteroaggregative E. coli (EAEC)
• enteroinvasive E. coli (EIEC)
• diffusively adherent E. coli (DAEC)