which of the following causes UTI & INDOL positive?
- klebsiella
- staphylococci
- E.coli***
------------------------
Coliform bacteria:
Coliform bacteria are the most common water test performed to determine the safety of private wells, water tanks and springs. But what exactly are these bacteria and how can they be treated in private water systems? This fact sheet provides an introduction to the measurement, prevention and treatment of coliform bacteria in drinking water.
What are coliform bacteria?
Coliform bacteria are made up of a large group of many types of bacteria that occur throughout the environment. They are common in soil and surface water and may even appear on your skin. A large number of certain types of coliform bacteria can also be found in the waste of humans and animals. Most types of coliform bacteria are harmless to humans, but some can cause mild illnesses and some can lead to waterborne diseases and are serious.
Coliform bacteria are often referred to as "indicator organisms" because they indicate the possible presence of bacteria that cause diseases in the water. The presence of coliform bacteria in the water does not guarantee that drinking the water will cause a disease. Rather, its presence indicates that there is a route of contamination between a source of bacteria (surface water, septic system, animal waste, etc.) and the water supply. Bacteria that cause disease can use this route to enter the water supply.
Specific types of coliform bacteria can be analyzed to determine, especially if after a total coliform bacteria test it is positive. These subgroups of coliform bacteria include fecal coliforms and Escherichia coli or E. coli. Faecal coliform bacteria are specific to the intestinal tract of warm-blooded animals, including humans, and therefore require a more specific test for sewage, animal or waste contamination. E. coli is a type of fecal coliform bacteria commonly found in the intestines of animals and humans. A positive E.coli as a result is much more serious than coliform bacteria alone, as it indicates that human or animal waste is entering the water supply. There are hundreds of strains of E. coli. Although most strains are harmless and live in the intestines of humans and healthy animals, a few strains can produce a potent toxin and can cause serious illness and death.
Health effects of coliform bacteria:
As mentioned earlier, water that is contaminated with coliform bacteria is not always a cause of disease. Most of these bacteria are harmless to humans. If the bacteria that cause disease are present, the most common symptoms are symptoms similar to stomach flu and general gastrointestinal such as fever, abdominal pain and diarrhea. Symptoms are more likely in children or older household members. In some cases, household residents acquire immunity to waterborne bacteria that are common in drinking water. In this case, home visitors who have not acquired immunity can get sick after drinking the water. Since the symptoms of drinking water with coliform bacteria are common to many human diseases, knowing that water is the source of the problem is difficult without having the water analyzed.
Drinking Water Standards:
Most of the bacteria in the coliform group do not cause the disease, but the higher their number, the greater the likelihood that disease-causing bacteria may be present. Since coliform bacteria usually persist in water like most disease-causing organisms, the absence of coliform bacteria leads to the assumption that the water supply is microbiologically safe to drink. Therefore, the drinking water standard requires that no coliform bacteria be present in drinking water. Fecal coliforms and E. coli should also be totally absent in drinking water.
Water test of coliform bacteria:
The most common water tests for bacteria is for total coliform bacteria. This test is available to the public and is inexpensive. Water tests for total coliform bacteria can be performed by a water analysis laboratory such as the Continent Laboratory.
Depending on the time of year and weather conditions can affect the occurrence and amount of coliform bacteria in wells and water tanks. Since coliform bacteria like to live near the surface of the earth and prefer warm temperatures, it is reasonable that the bacteria could be more likely to infect groundwater wells during warmer dates, or wetter climatic conditions when surface water It is recharging underground aquifers. Therefore, the greatest number of bacteria is probably found shortly after several weeks of rainy weather, while the bacteria in smaller quantities are in dry cold conditions in the winter. These variations in bacteria with the climatic conditions of the season should be considered when analyzing the water supply by bacteria.
For a proper water test for bacteria, it will be necessary for you to obtain a sterilized sample bottle from the laboratory and collect the sample strictly according to your instructions. If the sample is not collected in a sterile container, it can cause bacteria to enter during the sampling process.
Once in the laboratory, water can be analyzed for coliform bacteria using a variety of methods. A common method is to pass 100 milliliters (ml) of water through a membrane filter to capture the bacteria. The filter is then placed in a petri dish with agar to grow the bacteria overnight. If bacteria are present, they appear as colonies on the filter paper that can be seen on the. Bacterial results were reported as the number of colonies per 100 ml of water.
Other bacterial search test methods are performed by color changes in test tubes that have been incubated with a water sample. These methods can simply express coliform bacteria results as "present" (P) or "absent" (A). In this case, "present" only indicates that at least one bacterium was present in 100 ml of water. These presence / absence methods have become popular because they are simple, less expensive, and faster than enumeration methods. But, they also provide less information about the severity of the bacteria problem that may be useful when it comes to determining the causes and solutions.
There are other methods of testing coliforms-bacteria that are based on color changes, but also provide an estimate of the number of bacteria present. These are often referred to as (MPN) "most likely number" methods, which use a statistical relationship to estimate the number of bacteria in the sample based on the color changes in several test tubes.
Sometimes, the results of coliform bacteria such as “TNTC” (too numerous to count) or “confluent.” TNTC means that the concentration of bacteria was so high that it could not be counted (generally greater than 200 colonies per 100 ml) .Confluent means that numerous other coliform bacteria grew on the plaque, making identification of coliform bacteria impossible. In any case, another sample must be submitted to the laboratory to determine more precisely.
How common are coliform bacteria?
Coliform bacteria are one of the most common water pollution problems in private water systems in Argentina and worldwide. A 2006 survey of 450 private wells found coliform bacteria in approximately 35 percent and E. coli bacteria in approximately 15 percent of private wells.
Coliform bacteria are much more common in springs and shallow wells compared to deeper wells because bacteria are naturally filtered by soil and rock as surface water infiltrates the soil. Deeper wells (more than 30 meters) can still be contaminated by coliform bacteria if they are poorly constructed allowing water to flow along the surface of the well lining directly into the deep groundwater or if the land uses and surroundings They are causing pollution of deep groundwater.
- klebsiella
- staphylococci
- E.coli***
------------------------
Coliform bacteria:
Coliform bacteria are the most common water test performed to determine the safety of private wells, water tanks and springs. But what exactly are these bacteria and how can they be treated in private water systems? This fact sheet provides an introduction to the measurement, prevention and treatment of coliform bacteria in drinking water.
What are coliform bacteria?
Coliform bacteria are made up of a large group of many types of bacteria that occur throughout the environment. They are common in soil and surface water and may even appear on your skin. A large number of certain types of coliform bacteria can also be found in the waste of humans and animals. Most types of coliform bacteria are harmless to humans, but some can cause mild illnesses and some can lead to waterborne diseases and are serious.
Coliform bacteria are often referred to as "indicator organisms" because they indicate the possible presence of bacteria that cause diseases in the water. The presence of coliform bacteria in the water does not guarantee that drinking the water will cause a disease. Rather, its presence indicates that there is a route of contamination between a source of bacteria (surface water, septic system, animal waste, etc.) and the water supply. Bacteria that cause disease can use this route to enter the water supply.
Specific types of coliform bacteria can be analyzed to determine, especially if after a total coliform bacteria test it is positive. These subgroups of coliform bacteria include fecal coliforms and Escherichia coli or E. coli. Faecal coliform bacteria are specific to the intestinal tract of warm-blooded animals, including humans, and therefore require a more specific test for sewage, animal or waste contamination. E. coli is a type of fecal coliform bacteria commonly found in the intestines of animals and humans. A positive E.coli as a result is much more serious than coliform bacteria alone, as it indicates that human or animal waste is entering the water supply. There are hundreds of strains of E. coli. Although most strains are harmless and live in the intestines of humans and healthy animals, a few strains can produce a potent toxin and can cause serious illness and death.
Health effects of coliform bacteria:
As mentioned earlier, water that is contaminated with coliform bacteria is not always a cause of disease. Most of these bacteria are harmless to humans. If the bacteria that cause disease are present, the most common symptoms are symptoms similar to stomach flu and general gastrointestinal such as fever, abdominal pain and diarrhea. Symptoms are more likely in children or older household members. In some cases, household residents acquire immunity to waterborne bacteria that are common in drinking water. In this case, home visitors who have not acquired immunity can get sick after drinking the water. Since the symptoms of drinking water with coliform bacteria are common to many human diseases, knowing that water is the source of the problem is difficult without having the water analyzed.
Drinking Water Standards:
Most of the bacteria in the coliform group do not cause the disease, but the higher their number, the greater the likelihood that disease-causing bacteria may be present. Since coliform bacteria usually persist in water like most disease-causing organisms, the absence of coliform bacteria leads to the assumption that the water supply is microbiologically safe to drink. Therefore, the drinking water standard requires that no coliform bacteria be present in drinking water. Fecal coliforms and E. coli should also be totally absent in drinking water.
Water test of coliform bacteria:
The most common water tests for bacteria is for total coliform bacteria. This test is available to the public and is inexpensive. Water tests for total coliform bacteria can be performed by a water analysis laboratory such as the Continent Laboratory.
Depending on the time of year and weather conditions can affect the occurrence and amount of coliform bacteria in wells and water tanks. Since coliform bacteria like to live near the surface of the earth and prefer warm temperatures, it is reasonable that the bacteria could be more likely to infect groundwater wells during warmer dates, or wetter climatic conditions when surface water It is recharging underground aquifers. Therefore, the greatest number of bacteria is probably found shortly after several weeks of rainy weather, while the bacteria in smaller quantities are in dry cold conditions in the winter. These variations in bacteria with the climatic conditions of the season should be considered when analyzing the water supply by bacteria.
For a proper water test for bacteria, it will be necessary for you to obtain a sterilized sample bottle from the laboratory and collect the sample strictly according to your instructions. If the sample is not collected in a sterile container, it can cause bacteria to enter during the sampling process.
Once in the laboratory, water can be analyzed for coliform bacteria using a variety of methods. A common method is to pass 100 milliliters (ml) of water through a membrane filter to capture the bacteria. The filter is then placed in a petri dish with agar to grow the bacteria overnight. If bacteria are present, they appear as colonies on the filter paper that can be seen on the. Bacterial results were reported as the number of colonies per 100 ml of water.
Other bacterial search test methods are performed by color changes in test tubes that have been incubated with a water sample. These methods can simply express coliform bacteria results as "present" (P) or "absent" (A). In this case, "present" only indicates that at least one bacterium was present in 100 ml of water. These presence / absence methods have become popular because they are simple, less expensive, and faster than enumeration methods. But, they also provide less information about the severity of the bacteria problem that may be useful when it comes to determining the causes and solutions.
There are other methods of testing coliforms-bacteria that are based on color changes, but also provide an estimate of the number of bacteria present. These are often referred to as (MPN) "most likely number" methods, which use a statistical relationship to estimate the number of bacteria in the sample based on the color changes in several test tubes.
Sometimes, the results of coliform bacteria such as “TNTC” (too numerous to count) or “confluent.” TNTC means that the concentration of bacteria was so high that it could not be counted (generally greater than 200 colonies per 100 ml) .Confluent means that numerous other coliform bacteria grew on the plaque, making identification of coliform bacteria impossible. In any case, another sample must be submitted to the laboratory to determine more precisely.
How common are coliform bacteria?
Coliform bacteria are one of the most common water pollution problems in private water systems in Argentina and worldwide. A 2006 survey of 450 private wells found coliform bacteria in approximately 35 percent and E. coli bacteria in approximately 15 percent of private wells.
Coliform bacteria are much more common in springs and shallow wells compared to deeper wells because bacteria are naturally filtered by soil and rock as surface water infiltrates the soil. Deeper wells (more than 30 meters) can still be contaminated by coliform bacteria if they are poorly constructed allowing water to flow along the surface of the well lining directly into the deep groundwater or if the land uses and surroundings They are causing pollution of deep groundwater.
Bacteria extraction from drinking water:
Problems with wells or springs that test positive for coliform bacteria can sometimes be resolved with relatively simple measures. If the water supply tests are positive, consider the following steps to solve the problem.
- Confirm Test Results: Before making costly decisions about the water supply, make sure that the report of the coliform bacteria you have received is accurate. Make sure that you used a laboratory with experience and years in the market and that you have carefully followed the sample collection procedure using a sterile sample container. You may want to submit a second sample just to confirm the initial result. Also, if you had only done a presence / absence test, you may want to consider asking the laboratory to list the bacteria in the water. It is also important to track positive coliform bacteria tests with a test for E. coli bacteria to help determine the severity of the bacteria problem.
- System maintenance: Sometimes some simple maintenance of the water supply can eliminate the source of bacterial contamination. For example, you may want to extend the lining of the well over the ground and the slope of the ground away from the housing to prevent surface water from entering the well. Also, make sure that the upper part of the housing has a tight, sanitary lid that prevents insects and surface water from entering. If you have a spring, make sure the spring box is sealed to prevent insects and animals from entering. If E. coli bacteria are present, check your septic system for proper functioning and eliminate or divert obvious sources of animal waste from the entire well or spring.
- Chlorination of shock: In some cases, coliform bacteria can enter a well or spring at one time or event of temporary contamination, such as a severe storm or the installation of a new submersible pump. Shock chlorination can be used to disinfect a well or spring by introducing a high concentration of chlorine in the water for a short period of time. Once you have the chlorine collision of the water supply, the water from coliform bacteria should be re-analyzed in 10 to 14 days. If the coliform bacteria test is negative, it is likely that the contamination event has been treated successfully. If the bacteria have returned, you will have to consider a continuous disinfection treatment system such as those described below. A recent study from Laboratorio Continente found that approximately 15 percent of wells with coliform bacteria could be treated by chlorination shock in the well and the installation of a lid in the sanitary well. This was especially positive for wells that had small amounts of coliform bacteria (less than 10 colonies per 100 ml).
- Continuous disinfection: If shock chlorination is not successful in removing coliform bacteria from your water supply, you will have to consider buying a disinfection treatment system that continuously treats all the water that enters the home. Many types of disinfection treatment systems through the processes described below are commercially available.
Continuous disinfection methods:
Chlorination:
Municipal water treatment plants in Argentina continually add chlorine to ensure that their water is free of bacteria. Chlorination treatment systems are basically composed of a feeding system that injects a solution of chlorine (sodium hypochlorite) or dry powder (calcium hypochlorite) into the water in front of a storage tank. Most chlorinators use positive displacement feed pumps for the chlorine meter in the water. Other units may use suction type chlorinators or pellet drippers to deliver the chlorine.
The raw water that enters the chlorinator must be perfectly clear or free of any suspended sediment or cloudiness so that the chlorine can effectively kill the bacteria. Sometimes there is a sediment filter that is routinely installed in front of the chlorinator to remove small amounts of suspended material.
The chlorine that is injected into the water is consumed as it kills the bacteria. Chlorine is also consumed by impurities in water such as iron, hydrogen sulfide, and organic materials. The amount of chlorine needed to kill bacteria and oxidize all impurities in water is known as the demand for chlorine. Thus, the total amount of chlorine that must be injected into the water will depend on the chlorine demand of the raw water. Other characteristics of water such as pH and temperature will also affect the amount of chlorine that must be injected into the water. The objective of continuous chlorination is to provide enough chlorine to meet the demand for chlorine and still allow approximately 0.3 to 0.5 milligrams per liter of residual chlorine in the water. This residual chlorine is then arranged to kill the bacteria that can enter the water after the chlorinator.
The time required for chlorine to kill bacteria is known as the contact time. The required contact time will vary depending on the characteristics of the water, but a general rule is to provide approximately 30 minutes of contact time. Standard pressure tanks are generally not large enough to provide sufficient contact time, so a larger intermediate storage tank may need to be installed. Sufficient contact time can also be achieved by running the water through a series of spiral tubes. The time requirements can be shortened by increasing the dose of chlorine (super chlorination), but this may require the addition of a carbon filter to eliminate chlorine taste and smell.
Continuous chlorination treatment systems need significant maintenance. Chlorinators must be checked periodically to ensure proper operation and chlorine supplies must be continuously replenished. Both liquid and solid forms of chlorine are poisonous and irritating that must be handled in accordance with specific safety measures.
Ultraviolet light:
Ultraviolet (UV) radiation has become a popular option for disinfection treatment, since it does not add any chemicals to the water. However, UV light units are not recommended for water supply where total coliform bacteria exceed 1,000 colonies per 100 ml or fecal coliform bacteria exceed 100 colonies per 100 ml.
The unit consists of a UV lamp covered by a quartz crystal cover (Figure 2). Water radiates with UV light as it flows over the glass sleeve. Untreated water entering the unit must be completely clean and free of any suspended sediment or turbidity to allow all bacteria to be irradiated by light. A sediment filter is often installed in front of the UV unit to remove any sediment or organic matter before it enters the unit. The quartz crystal case should also be kept free of any film. Overnight cleaning solutions can be used to keep the glass sleeve clean, or optional windshield wipers can be purchased with the unit to manually clean the glass. Water with a high hardness (calcium and magnesium) can also coat the sleeve with scale (an off-white hardness reservoir), which may require routine cleaning or the addition of a water softener. The unit also requires electricity and will cause a small but noticeable increase in your electricity bill per month.
The disadvantage of this system is that it only kills the bacteria inside the unit and does not provide any residual disinfectant for bacteria that can survive or be introduced into the pipe after the UV light unit. Maintenance requirements are minimal for UV units, but the bulb will slowly lose intensity over time and will require replacement once a year. Some units are equipped with a UV light intensity sensor that can detect when the bulb is not emitting enough UV light. These sensors add to the initial cost of the unit, but can pay for themselves in a longer life of the bulb.
Other options:
Numerous other treatment processes can be used to disinfect water. They are not recommended for continuous disinfection for a variety of reasons.
Boiling:
Boiling the water for about a minute effectively kills the bacteria. This method is frequently used to disinfect water in emergency situations or at the campsite. Boiling is time and energy intensive, however, and only provides small amounts of water. It is not a long term or the continuous option for disinfection of water supply.
Ozonation:
In recent years, ozonation has received more attention as a method for treating water quality problems including bacterial contamination. Like chlorine, ozone is a strong oxidant that kills bacteria, but it is a much more unstable gas that must be generated in place using electricity. Once ozone is produced, it is injected into the water where bacteria is killed. General ozonation units are not recommended for disinfection since they are much more expensive than chlorination or UV light systems. They can be useful where multiple water quality problems should be treated, such as disinfection in combination with the removal of iron and manganese.
Iodization:
Iodine has been used in the past, similar to chlorine, to continuously disinfect water. Iodization is no longer considered a permanent disinfection option due to health problems related to long-term exposure to low levels of iodine in wastewater. The Argentine Environmental Protection Agency now recommends iodination only for short term or emergency disinfection. Iodine tablets are a popular choice among campers and hikers for water disinfection.
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Clinical Pathology