Bacteria coliforms in water. Thermotolerant coliforms

Bacteria coliforms are always present in the digestive tract of animals and humans, as well as in waste products of their vital activity. They can also be found on plants, soil and water, the contamination of which is a serious problem because of 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 Escherichia coli can cause serious diseases. In addition to humans, sheep and cattle can be infected. It is disturbing that the contaminated water in its external characteristics does not differ from ordinary drinking water to taste, smell and appearance. Bacteria coliforms are found even in well water, which is considered to be impeccable in all senses. Verification is the only reliable way to learn about the presence of pathogenic bacteria.

What happens when I find it?

What if the coliforms or any other bacteria are found in drinking water? In this case, repair or modification of the water supply system is required. When used for disinfection, obligatory boiling is provided, as well as repeated testing, which can confirm that the contamination was not eliminated if these were thermotolerant coliform bacteria.

Indicator organisms

Common coliform bacteria are often called indicator organisms, because they indicate the potential presence of pathogenic bacteria in water, for example, 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 illnesses and even lead to death. If pathogens are present in the body, the most common symptoms are gastrointestinal upset, fever, abdominal pain and diarrhea. Symptoms are more pronounced in children or elderly family members.

Safe water

If there are no total coliform bacteria in the water, then it can almost certainly be assumed that it is microbiologically safe for drinking.
If they were found, then additional tests would be justified.

Bacteria love heat and moisture

Temperature and weather conditions also play an important role. For example, E. coli prefers to live on the surface of the earth and loves heat, so that coliform bacteria in drinking water appear as a result of movement in the composition of underground streams under warm and humid weather conditions, while the smallest number of bacteria will be found in the winter season.

Impact chlorination

To effectively destroy bacteria, chlorine is used, which oxidizes all impurities. Its quantity will be affected by water characteristics such as pH and temperature. On average, the weight of dry matter per liter is approximately 0.3-0.5 milligrams. To kill the common coliform bacteria in drinking water, it takes about 30 minutes. The contact time can be reduced by increasing the chlorine dose, but this may require additional filters to remove the specific taste and odor.

Destructive ultraviolet light

A popular variant of disinfection is considered to be ultraviolet rays. This method does not imply the use of any chemical compounds. However, this remedy is not used where the total coliform bacteria exceed one thousand colony per 100 ml of water. The device itself consists of a UV lamp surrounded by a sleeve made of quartz glass, through which liquid flows, irradiated with ultraviolet light. Untreated water inside the appliance should be completely clean and free of any visible contaminants, blockages or turbidity to allow exposure to all harmful organisms.

Other cleaning options

There are many other treatment methods used for water disinfection. However, they are not recommended as long-term for various reasons.

• Boiling. At 100 degrees Celsius, bacteria are effectively killed within 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 amounts of water. This is not a long-term or permanent option for water disinfection.
• Ozonation. In recent years, this method is used as a way to improve water quality, eliminate various problems, including bacterial contamination. Like chlorine, ozone is a strong oxidant that kills bacteria. But at the same time, this gas is unstable, and it can only be obtained with the help of electricity. Ozonation blocks are usually not recommended for disinfection, because they are much more expensive than chlorination or ultraviolet systems.
• Iodination. Once a popular method of disinfection recently recommended only for short-term or emergency disinfection of water.

Thermotolerant coliforms

This is a special group of living organisms that are able to ferment lactose at 44-45 degrees Celsius. These include the genus Escherichia and some species of Klebsiella, Enterobacter and Citrobacter. If there are extraneous organisms in the water, this indicates that it has not been properly purified, re-contaminated, or contains nutrient elements in excess. When they are detected, it is necessary to check for the presence of exactly resistant to elevated temperature coliform bacteria.

Microbiological analysis

Coliform organisms belong to the class of gram-negative bacteria that outwardly resemble a rod, they live and reproduce in the lower part of the digestive tract of animals and humans. In general, bacteria include many varieties that are dangerous to one degree or another. Microbiological analysis also includes the identification of all kinds of viruses and parasites. The microbiological analysis is carried out not only to check the drinking water, but also to check the safety of those reservoirs where people enjoy their leisure. Some, of course, are not afraid of bathing in the water, where a "stick" was discovered, but the safety of such water is also regulated. There are certain hygienic requirements for the state of surface waters.

If coliforms were found, then this may indicate that pathogenic microorganisms have 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, which range from mild violations of the digestive tract to severe forms of dysentery, cholera, typhoid fever and many others.

Household sources of infection

The quality of drinking water is monitored and regularly monitored by specialized sanitation services. And what can an ordinary person do to protect himself and protect him from unwanted infection? What are the sources of water pollution in the home?

1. Water from the cooler. The more people touch this device, the more likely the penetration of harmful bacteria. As studies show, water in every third cooler is simply teeming with living organisms.
2. Rainwater. Surprisingly, the moisture collected after the rain is a favorable environment for the development of coliform bacteria. Advanced gardeners do not use this water, even for watering plants.
3. Lakes and reservoirs are also considered to be at risk, as all living organisms, not just bacteria, multiply faster in stagnant water. An exception can be called the oceans, the development and spread of harmful forms there is minimal.
4. The condition of the pipeline. If the sewers did not change and were not cleaned for a long time, it could also lead to trouble.