Back to: MICROBIOLOGY 400 LEVEL
Welcome to class!
Hello, star learner! It’s always a joy to have you here. You’re doing so well, and today’s topic is one that affects our everyday life in Nigeria—Indicators of Water Quality, especially focusing on E. coli and coliforms. Clean water is life, and knowing how to test water for safety is key to preventing diseases. Whether it’s the water from a borehole, sachet, or stream, it must be checked to make sure it’s safe for drinking and other uses.
Indicators Of Water Quality (E. Coli, Coliforms)
Water quality refers to how safe and clean water is for human use—especially for drinking. We use indicators to test water. These are specific organisms or substances that tell us whether the water is likely to be contaminated. The most common biological indicators are coliform bacteria, particularly Escherichia coli (E. coli).
1. Coliform Bacteria
Coliforms are a group of bacteria naturally found in the environment, especially in soil, vegetation, and the intestines of warm-blooded animals.
Their presence in water means that there may be faecal contamination—in simple terms, the water may be mixed with sewage or animal waste.
While not all coliforms are harmful, their presence is a warning that other dangerous pathogens (like cholera or typhoid-causing bacteria) may also be in the water.
2. Escherichia coli (E. coli)
E. coli is a type of faecal coliform. It lives in the intestines of humans and animals.
Unlike general coliforms, E. coli specifically points to faecal contamination from humans or animals.
Some strains of E. coli can cause diarrhoea, vomiting, and even kidney failure, especially in young children and the elderly.
In Nigeria, water from shallow wells, rivers, or broken pipes can easily become contaminated with faeces, especially in places without proper drainage or sewage systems.
How Are These Indicators Detected?
Water samples are taken and cultured in labs to see if these bacteria grow.
If coliforms or E. coli are present, the water is considered unsafe for drinking.
Testing is done regularly for public water sources like boreholes, treatment plants, and packaging companies.
Why This Matters
Using indicators like E. coli and coliforms helps health and environmental officers detect dangerous water early and prevent disease outbreaks. It also helps in designing better water treatment systems and protecting public health.
Summary
- Water quality refers to how clean and safe water is for use.
- Indicators help us know if water may be contaminated.
- Coliform bacteria are common indicators found in the environment.
- Their presence in water suggests possible contamination with waste.
- E. coli is a type of coliform that specifically indicates faecal pollution.
- Some strains of E. coli can cause serious illness.
- These bacteria are detected through lab tests of water samples.
- Contaminated water can lead to diseases like typhoid, cholera, and diarrhoea.
- Regular testing helps protect public health and ensure clean water supply.
Evaluation
- What does the presence of E. coli in water usually indicate?
- How are coliform bacteria useful in testing water quality?
- Name two health risks associated with contaminated drinking water.
You’ve just learned something that could help you save lives and improve health in your community. Your journey with Afrilearn is turning you into a solution-bringer. Stay sharp and keep learning—there’s more exciting knowledge coming your way! See you in the next class!