The objects of sanitary microbiology are the microscopic flora of this world and its ability to influence human health and population. Research in this area gives scientists an idea of the factors that correct the incidence and epidemiological situation. However, not only for epidemiologists through this science a lot of new and useful information comes to light: microbiology is also relevant for hygienists.
The importance of the topic
Medical and sanitary microbiology is a science through which it is possible to assess the dangers of various environments surrounding a person. We study the soil, air and water masses, everyday household items used by people. In the framework of microbiology, objects detected on medical equipment are investigated. The task of scientists is to identify and clarify all possible mechanisms and factors for the transmission of pathogens of various infectious diseases. Particular attention is paid to intestinal transmitted through wounds and by airborne droplets.
As part of teaching the basics of sanitary microbiology in educational institutions, students are told how to obtain samples so that their studies show the correct results, what methods are used to analyze them. Already at the stage of primary education, students should be guided in the acceptable levels of pollution, as well as have an idea of the documentation by which these levels are established. In our country, special rules, rules adopted by legislative structures apply. Accounting for this documentation is mandatory for all employees in this area. Methodological guidelines and other documents have been developed that regulate the work of specialists in the field of microbiology.
The nuances of the process
The tasks and methods of sanitary microbiology rarely include the determination of species in specific samples and their precise identification. As a rule, scientists work with some conditional microbial groups. To determine whether it belongs to it, it is necessary to identify some minimal set of features. Evaluate morphology, cultivation, enzymatic features.
About environments: soil
Sanitary soil microbiology is one of the main subsections of science. You can not underestimate its significance, because it is the soil - the reservoir of many microscopic life forms. In combination with flora and fauna, such creatures form complex biogeocenoses. The structure and type of a particular soil determine which microorganisms will dwell here, what is their density, activity, how diverse is the composition of the colonies. The organic, mineral composition of a particular site, the physical state, chemical characteristics, heating, the level of acidity and humidity play a role - in a word, all the nuances that determine the state of the soil.
Scientists involved in sanitary soil microbiology have found that up to 6 tons of microbes can be contained in a 15-centimeter layer within one hectare. The density of such life forms is highest at a depth of 10-20 cm, but layers over one meter above the surface are poor in microorganisms. From five meters and deeper, the soil is likely to be sterile.
Processes and their causes
One of the main tasks of sanitary microbiology is to determine the causes of pathogenic life forms entering the environment, to find out how they multiply and develop. Regarding soils, in particular, it was found that the main percentage of dangerous microorganisms enter the soil with pus, saliva, feces, urine and other organic secretions of animals, humans, birds. The source of dangerous microbes are the bodies of dead creatures, especially if infectious pathologies have become the cause of death. Contamination of the soil with pathogenic and conditionally considered such life forms is observed during the discharge of wastewater from industrial facilities, as well as domestic, sewer.
One of the goals of sanitary microbiology is to determine the characteristics of pathogenic microbes, including the timing of their survival in a certain environment. It was established that in the soil they vary significantly. Some life forms that do not generate spores can exist for days and months, others for years and tens of years.
For spore-forming pathological bacteria, the soil may turn out to be a natural place of existence. This explains, for example, gangrene, tetanus against the background of contamination of the wound by the ground. Some organisms live in the soil, die, which leads to the formation of toxic substances for humans. Usually death occurs due to lack of water, heat, nutrients, due to the influence of direct sunlight or the appearance of antagonist microbes.
We’ll check everything!
Soil is such an environment for sanitary microbiology, the studies of which are extremely important, since their findings are relevant for many sciences, including practical medicine. The main task of studying the soil is to prevent infection of people, sanitary control and supervision, taking into account compliance with the standards. Specialists in this science are involved in investigations of disasters and epidemics, environmental accidents. Soil analysis is made short or extended - it depends on the requirements of the case. For example, ongoing environmental monitoring requires an assessment of fecal contamination, if any. If a high concentration of bacteria is revealed that allows talking about such pollution, the region is considered unsuccessful in terms of sanitary indicators. To assess the condition of the soil, samples are taken for laboratory research and the contents of Escherichia coli, streptococcus are revealed. If available, the pollution is fresh. Cyto-, enterobacteria indicate stale, some old forms of clostridia are indicative of old.
The methods of sanitary microbiology used in soil research are sometimes used as part of a preventive study to identify indicators whose analysis allows us to assess the likelihood of an epidemic. Having received the results of laboratory tests, the data are compared with the standards adopted in the country. It is important not only to evaluate the content of life forms and their types, but also the composition of the soil, the influence of climate. At present, there is no single standard for soil assessment in the framework of the described science.
Water is the basis of life
Sanitary microbiology of water is no less important branch of science than discussed above. Like the earth, the liquid of open reservoirs is the medium of the existence of microscopic organisms, algae, protozoa. It is customary to talk about autochthonous and allochthonous microflora. The second type is microorganisms coming from the earth, air and from different creatures. Water is the area of localization of biological purification processes, the task of which is to get rid of allochthonous microflora.
Sanitary microbiology of water is a science that studies the concentration and composition of microorganisms in water bodies and the dependence of these indicators on various factors. So, it was found that the presence of organic substances strongly affects the concentration of microbes. Groundwater is considered the cleanest, since microflora are retained in the soil by the passage of fluid through it. But open water bodies are rich in microbes, since a large amount of substrate, useful for microflora, is dissolved in water. This comes from the sewage system and with sewage, industrial waste.
Relevance of the problem
One of the goals of sanitary microbiology is to assess the environmental impact of a person and the products of his activity. Particular attention is paid to wastewater. Their volumes are growing every year, and a huge amount of microflora gets into the reservoirs. With such volumes, the liquid does not have time to cleanse itself, and for every milliliter there are several million microbes.
Sanitary microbiology determines how strongly the effect of contaminated water on the spread of disease. It has long been proven that this is an important epidemiological factor for intestinal diseases. Allocations of sick individuals, carriers of pathogens of the disease appear in open water, from where they gradually penetrate into drinking water. All this threatens the spread of poliomyelitis, dysentery, hepatitis, typhoid and other dangerous diseases.
About terms and phenomena
As can be concluded from all of the above, sanitary microbiology is such a science whose task is to protect the environment from pathogenic life forms. Specialists who have chosen it as their line of business are investigating the effect of microscopic external flora on human health. The discipline is independent, it is dedicated to the microbiota and its features to harm the human population.
The main task of sanitary microbiology is the assessment of external objects according to the main indicators considered in this science. Standards are also being developed to reflect in which case the facilities are safe. Specialists in microbiology should generate new research methods, expertly evaluate their accuracy and effectiveness, and also apply such techniques to study the external environment. The tasks of science include the formation of recommendations regarding techniques and methods for improving the environment through the impact on the microflora. Specialists in microbiology should evaluate the effectiveness of such measures.
An equally important task of sanitary microbiology is the study of the laws of the life cycle of microscopic life forms that live in the human environment. At the same time, attention is paid not only to the relationship with the human population, but also to the existence of microbes and bacteria in the ecological system.
Science Methods
Modern sanitary microbiology uses two main methods of work - this is the direct identification of microscopic forms and indirect indication, which allows to assess the likelihood of microflora. The first option is considered significantly more reliable, but the level of sensitivity is still low, and the work itself is labor-intensive. The complexity of the determination is associated both with a low concentration and with the non-uniformity of microbial colonization of the medium, with competition between different species, and the presence of saprophytes. Pathogens are constantly changing, which further complicates the task. As a rule, a direct determination is made when there are epidemiological indications for this.
Sanitary food microbiology has an alternative method of identifying life forms - an indirect one. It is easier to implement, this approach is more accessible. There are two criteria on the basis of which the studied medium is evaluated: microbial number, concentration of indicative microscopic life forms. Microbial number - the number of organisms per gram or cubic centimeter. It is believed that the greater the value, the higher the likelihood of the presence of pathogenic organisms, which means that it is possible to assess the epidemic situation.
The nuances of the question
The main task of the sanitary microbiology of air, soil, food, medical equipment and other objects is to assess whether there is a pathological microflora in a particular area and how numerous it is. Currently, it is quite difficult to deal with this issue - this is due to both the imperfection of technologies and the features of the objects under study. Currently applicable methods take into account that the main source of infectious agents is warm-blooded creatures, including humans. It is these populations that release pathogenic life forms into the environment.
In the study of soil and water, air and food products in sanitary microbiology, they take into account the features of the natural environment for pathogenic and conditionally such life forms. For many, this, for example, the intestinal tract of warm-blooded creatures. The identification of a typical intestinal microflora in a sample indicates a high probability of the presence of pathogens of cholera and typhoid. For other life forms, the biotope is the oral cavity. By studying microorganisms, it is possible to assess the disadvantage of the region, so that their concentration has become a sanitary-indicative factor.
Sanitary-indicative - what are these?
These include only microscopic life forms that are constantly contained in the secretions of warm-blooded creatures, enter the environment in a fairly high concentration, and do not have alternative natural reservoirs. Such microflora should retain the ability to survive in the environment after isolation of a certain time period comparable with the survival time of pathogenic microflora.
Microorganisms capable of active reproduction outside the body of a warm-blooded creature cannot be taken as sanitary-indicative. Correction of biological properties is also not allowed when it enters the external space relative to the body of the carrier. Microbiologists are only interested in typical life forms, so that diagnosis is not too serious a problem.
When choosing sanitary-indicative life forms, only those that modern methods and means can be accurately and easily calculated and evaluated are taken into account. The growth of such microorganisms in the nutrient substrate should not be controlled and depend on other representatives of microscopic life forms. An important condition is the uniform distribution of microorganisms in the environment. For example, when studying dense food objects, homogenization is necessary to evaluate microbial filling.
The choice of a microorganism as a sanitary-indicative is possible only if it is found both in the host organism and in the external environment in a higher concentration than the pathogenic form of life.
All at once: is this possible?
Determining the extent to which a particular variant of the microorganism is applicable for analysis as a sanitary-indicative one, it is necessary to check it for compliance with all the above conditions. The more correspondences are observed, the more accurate will be the result of analyzes using it. In practice, it is not always possible to choose a microflora that would completely satisfy all of the above requirements. In this case, it is necessary to dwell on the closest to the ideal set of qualities.
About fluid
To determine how safe the water used for drinking is food, food and products, mineral waters, treatment and canteens, surface wastewater, open, and also therapeutic mud, one should resort to unified methods. They are regulated by the laws of the country, GOSTs are adopted, guidelines are developed.
For drinking water, it was established that per milliliter of liquid should account for no more than a hundred microbes in general, while if the index per liter should be within three. The presence of Escherichia coliphages in a liter of water is unacceptable. When identifying them, you can not drink water for drinking. When analyzing 25 l, the simplest, helminth eggs should not be detected.
About Standards: Continuing Review
Identifying the features of products intended for feeding children, it is necessary to assess the presence of intestinal pathogens. For 10 cubic centimeters there should not be a single sample, for 100 cm 3 - there should be no pathogenic bacteria. In each cubic centimeter there can be up to hundreds of colony forming units of microorganisms.
For dairy products intended for children, at 3 cm 3 there should not be representatives capable of provoking intestinal diseases. When analyzing 10 cm 3 , coli and streptococcus should not be detected, and five times more in the volume - no pathogenic bacteria. For drinks and cereals, cottage cheese for each gram should not reveal representatives of these life forms, including salmonella.
Food microbiology
To some extent, it is thanks to this science that the food industry can exist in the form in which it is known to modern man. The products contained in the refrigerators of ordinary citizens are the result of the work of scientists specializing in microbiology. In relation to food, they are developing new methods of protecting products from dangerous forms of life without losing their taste and aromatic qualities.
In stores you can find a huge variety of products, the manufacture of which is possible only through cultured microscopic life forms. People rarely think, but it was thanks to such colonies, put at the service of humanity, that production of kefir, cottage cheese and sour cream, and other similar products became available on an industrial scale.
Another important industry is egg microbiology.This product inside is exceptionally sterile and rich in lysozyme (protein structure), which is able to destroy pathological microscopic life forms that have leaked through the natural barrier - the shell. In order for the egg to be stored for a long time and not be a source of danger to humans, microbiologists are developing storage methods, norms and rules in which the natural ability to protect contents is stored for a long time.