Coliform bacteria are always present in the digestive tract of animals and humans, as well as in waste products. They can also be found on plants, soil and in water, pollution of which is a serious problem due to the possibility of infection with diseases caused by various pathogens.
Harm to the body
Are coliform bacteria harmful? Most of them do not cause disease, however, some rare strains of E. coli can cause serious illness. In addition to humans, sheep and cattle can be infected. It is disturbing that contaminated water in its external characteristics is no different from ordinary drinking in taste, smell and appearance. Coliform bacteria are found even in well water, which is considered to be impeccable in every sense. Screening is the only reliable way to find out about the presence of pathogenic bacteria.
What happens upon detection?
What if coliform bacteria or any other bacteria are found in drinking water? In this case, you will need to repair or modify the water supply system. When used for disinfection, mandatory boiling is provided, as well as repeated testing, which can confirm that the contamination was not eliminated if it was thermo-tolerant coliform bacteria.
Indicator organisms
Common coliform bacteria are often called indicator organisms because they indicate the potential presence of pathogenic bacteria in water, such as E. coli. Although most strains are harmless and live in the intestines of healthy people and animals, some of them can contribute to the formation of toxins, cause serious illness, and even lead to death. If pathogenic bacteria are present in the body, the most common symptoms are upset gastrointestinal tract, fever, abdominal pain and diarrhea. Symptoms are more pronounced in children or elderly family members.
Safe water
If there are no common coliform bacteria in water, then with almost complete certainty we can assume that it is microbiologically safe for drinking.
If they were discovered, then it would be justified to conduct additional tests.
Bacteria love heat and moisture.
Temperature and weather conditions also play an important role. For example, Escherichia coli prefers to live on the surface of the earth and loves heat, so the coliform bacteria in drinking water appear as a result of movement in underground streams in warm and humid weather conditions, while the least bacteria will be found in the winter season.
Shock chlorination
To effectively kill bacteria, chlorine is used, which oxidizes all impurities. Its quantity will be influenced by such characteristics of water as pH and temperature. On average, the dry matter weight per liter is approximately 0.3-0.5 milligrams. It takes about 30 minutes to kill common coliform bacteria in drinking water. Contact time can be shortened by increasing the dose of chlorine, but this may require additional filters to remove a specific taste and smell.
Disastrous ultraviolet light
A popular disinfection option is ultraviolet rays. This method does not imply the use of any chemical compounds. However, this tool is not used where total coliform bacteria exceed one thousand colonies per 100 ml of water. The device itself consists of a UV lamp surrounded by a sleeve of quartz glass, through which a liquid flows, irradiated with ultraviolet light. The untreated water inside the apparatus must be completely clean and free of any visible contaminants, blockages or turbidity in order to allow exposure of all harmful organisms.
Other cleaning options
There are many other treatment methods used to disinfect water. However, they are not recommended as long-lasting for various reasons.
- Boiling. At 100 degrees Celsius, bacteria are effectively killed in one minute. This method is often used to disinfect water during emergencies or when necessary. This takes time and is an energy-intensive process and, as a rule, is used only in small quantities of water. This is not a long-term or permanent option for disinfecting water.
- Ozonation In recent years, this method has been used as a way to improve water quality and eliminate various problems, including bacterial infection. Like chlorine, ozone is a powerful oxidizing agent that kills bacteria. But at the same time, this gas is unstable, and it can only be obtained with the help of electricity. Ozonation units are generally not recommended for disinfection because they are much more expensive than chlorination or ultraviolet systems.
- Iodization. The once popular disinfection method has recently been recommended only for short-term or emergency disinfection of water.
Thermo-tolerant coliform bacteria
This is a special group of living organisms that are capable of fermenting lactose at 44-45 degrees Celsius. These include the genus Escherichia and some species of Klebsiella, Enterobacter and Citrobacter. If extraneous organisms are present in the water, this indicates that it was not adequately cleaned, re-contaminated, or it contains nutrients in excess. When they are detected, it is necessary to check for the presence of coliform bacteria that are resistant to elevated temperature.
Microbiological analysis
Coliform organisms belong to the class of gram-negative bacteria that look like a stick, they live and multiply in the lower digestive tract of animals and humans. In general, bacteria include many species that are dangerous to one degree or another. Microbiological analysis also includes the identification of all kinds of viruses and parasites. Microbiological analysis is carried out not only to check drinking water, but also to check the safety of those reservoirs where people spend their leisure time with pleasure. Some, of course, are not afraid of swimming in the water where the "wand" was discovered, but the safety of such water is also regulated. There are certain hygiene requirements for surface water.
If coliforms were found, then this may indicate that pathogenic microorganisms entered the water . Thus, various diseases begin to spread. In contaminated drinking water you can find strains of salmonella, shigella, E. coli and many other pathogens that range from mild digestive tract disorders to severe forms of dysentery, cholera, typhoid fever and many others.
Household sources of infection
The quality of drinking water is monitored, it is regularly checked by specialized sanitary services. And what can an ordinary person do to protect himself and protect him from unwanted infection? What are the sources of domestic water pollution?
- Water from the cooler. The more people touch this device, the more likely it is that harmful bacteria will enter. As studies show, water in every third cooler is simply teeming with living organisms.
- Rainwater. Surprisingly, moisture collected after rain is a favorable environment for the development of coliform bacteria. Advanced gardeners do not use such water even for watering plants.
- Lakes and reservoirs are also at risk, since in living water all living organisms multiply faster, and not just bacteria. An exception can be called oceans, the development and spread of harmful forms there is minimal.
- The condition of the pipeline. If the sewers do not change and do not clean for a long time, then this can also lead to troubles.