Diseases caused by bacteria are currently considered the most common of all that can appear in humans. Today, there are many pathologies and microorganisms that provoke them. Next, we will consider in detail the diseases caused by bacteria. The table that will be given at the end of the article will contain basic information about pathologies and pathogens.
General information
Pathogenic (disease-causing) microorganisms have a cell wall and a unique set of defense and aggression factors. Many people know such pathologies as scarlet fever, acute respiratory infections, pyelonephritis, plague, salmonellosis, syphilis, gonorrhea, tetanus, tuberculosis. The cause of their development are pathogenic bacteria. Diseases can proceed in different ways, have several stages, degrees of severity. Treatment of a particular pathology is carried out on the basis of the results of the tests.
Characterization of bacteria
What is a pathogen? It is a microscopic organism that, unlike prions and viruses, has a cell wall. There are the following types of bacteria:
- Non-pathogenic.
- Conditionally-pathogenic.
- Pathogenic.
Let's consider the features of bacteria that provoke pathologies. The negative effect of microorganisms is due to the presence of special aggressive devices in them. Among them, the following factors should be highlighted:
- Adhesion. With it, the microorganism has the ability to attach to various human tissues.
- Exotoxin. This factor has a specific effect, causing a particular symptom. For example, damage to the nervous system provokes butulotoxin, the gastrointestinal system - enterotoxin, and so on.
- Endotoxin. This liposaccharide provokes fever and intoxication syndrome.
These "devices" are fully equipped with pathogenic bacteria. Examples of such microorganisms: salmonella, pale treponema, gonococcus, bacillus Luffner. Conditionally pathogenic bacteria can be in a person without causing pathologies in the norm. However, under certain conditions, they turn into harmful bacteria. Examples of such microorganisms: staphylococcus, streptococcus, proteus and some others. Conditionally pathogenic elements are necessary for the body. Thanks to their presence, balance is maintained. Some intestinal bacteria are considered opportunistic pathogens. The last category of microorganisms does not cause any negative conditions under any conditions. At the end of the article there is a table "Human Diseases Caused by Bacteria". It contains pathogenic microorganisms that provoke various infectious pathologies.
In what cases does the development of pathology occur?
In order for a pathogenic bacterium to cause pathology in a person, several conditions must be met. First of all, the number of microorganisms must be sufficiently large. 1-2 bacteria are actually not capable of seriously infecting a person, since specific and non-specific defense systems can cope with such minor threats quite well. Microorganisms must also be complete. This means that they must have all the necessary pathogenic properties. Weak strains do not pose a particular danger to humans. They can only transfer their properties to immunity so that the defense system can subsequently adequately respond to the enemy. It is on this principle that the action of various vaccines is based. Parasitic bacteria should penetrate into that part of the body where they could quickly and reliably attach for further growth, reproduction and introduction. For example, if salmonella does not enter the gastrointestinal tract, but on the skin, then a person will not develop salmonellosis. Therefore, for prevention, before eating, you should wash your hands. Human immunity must be prepared to repel any attack. If the protective system is grafted artificially or naturally, then in almost all cases, parasitic bacteria cannot break through this barrier. If the immune system has never encountered microorganisms or is weakened (with AIDS, for example), then it will not be so difficult for the pathogen to invade the body and multiply there. When these conditions are met, infectious diseases occur. Pathologies caused by bacteria do not immediately beginbe accompanied by certain symptoms.
Incubation period
It exists in every infection. During it, bacteria get used to a new place, multiply, develop. The incubation period can last from several hours (for example, with food poisoning) to several years (with tick-borne borreliosis, leprosy). From the moment the first symptoms began to appear, we can say that the pathology is fully developing. The incubation period is over, groups of bacteria have settled throughout the body. With some pathologies, the immune system is able to cope on its own. But in some cases he needs outside help.
How are diseases caused by bacteria diagnosed?
The detection of pathologies is carried out in several ways:
- Using a microscope (microscopy with staining is performed).
- Determination of antigens and antibodies. This category of research includes laboratory analyzes of ELISA, PCR, RIF and others.
- With the help of sowing. Material with harmful bacteria is placed in a special nutrient medium and left in it for a week. After this period, they look at what has formed and make a conclusion.
- Infection of animals. This biological method involves the introduction of material into the body of mice, rats and other experimental subjects. An autopsy is then performed and the insides are examined under a microscope.
Therapeutic interventions
Diseases,caused by bacteria are treated with various antibiotics. The use of drugs is the main therapeutic method for infectious pathologies. There are a lot of antibiotics on the market today. The action of some may be directed against any particular group of bacteria. Other drugs have a wide spectrum of activity. The use of antibiotics must be treated with great care. It should be remembered that illiterate treatment (as a rule, independent, without consulting a doctor) can lead to serious consequences.
Antibiotic resistance
It occurs in microorganisms due to their ability to mutate. Sooner or later, bacteria develop resistance to a particular drug. Medicines cease to act - to neutralize harmful microorganisms. In such cases, specialists prescribe stronger drugs - the means of the next, new generation. Medicine is considered indirectly responsible for the occurrence of infections that arose as a result of therapeutic assistance. Previously, such pathologies were called nosocomial (hospital). They differ from ordinary diseases just in that simple (traditional) medicines do not have the necessary effect, and one has to resort to stronger drugs. Relatively recently began to appear, for example, multidrug-resistant tuberculosis strains. Today, there are not many medicines for this disease. Basically what was developed in the USSR is used. These medicines do not work on a new type of infection. Such patients are not onlyare incurable, but also extremely dangerous for others, as they are carriers of pathogenic bacteria.
Reason for drug resistance
Antibiotic resistance is considered a fairly natural process. This is due to the ability of a microorganism, like all living things, to adapt to constantly changing environmental conditions. However, the rate of development of antibiotic resistance was significantly affected by the inept use of medicines. Relatively recently, antibiotics were sold in pharmacies without a prescription. In this regard, many people went and purchased medicines without consulting a doctor. As a rule, self-treatment ends after 1-3 days, when the symptoms disappear. This leads to incomplete destruction of pathogenic bacteria. Some of them are eliminated, and the rest mutate, turning into another L-form. They are distributed throughout the body and take a wait-and-see attitude. When favorable conditions arise for them, they are activated. To prevent such consequences, antibiotics are prescribed in courses of 5 to 14 days. Microorganisms must be completely destroyed, not adapted to drugs.
The main problem of antibiotic therapy
Along with pathogenic bacteria, the use of medicines destroys beneficial microorganisms that inhabit the gastrointestinal tract, for example. Imbalance can lead to the fact that opportunistic elements can turn into harmful ones. One of the most common complications of antibiotic therapy isdisease like dysbacteriosis. The elimination of pathology is carried out by stimulating the growth of beneficial microflora.
Clinical picture of infection
The first symptom of a bacterial disease is fever. It is caused by the fact that when the cell wall of the microorganism is destroyed, the LPS complex penetrates into the bloodstream and reaches the hypothalamus, and then the thermoregulatory center in it. As a result, the set point shifts, and the body begins to "think" that it is cold. Therefore, heat production increases and heat transfer decreases. Fever acts as a defensive reaction. Temperature up to 39 degrees. stimulates the activity of the immune system. If this indicator is exceeded, it is necessary to take antipyretics. As such a drug, the medicine "Paracetamol" can act. The temperature can be indirectly lowered with antibiotics. With its decrease during the first 24-28 hours from the start of administration, it can be concluded that the drug is correctly selected. Another manifestation of the infectious process is intoxication syndrome. It is manifested by a significant deterioration in the condition, a decrease in mood, apathy, muscle and joint pain. Probably nausea, vomiting. Relief of the condition will help the reception of a large volume of liquid (at least two liters). Excess water will dilute the toxins, reduce their concentration and excrete some of them in the urine. These two symptoms described above are considered universal and appear in almost all infections. All other signs are determined by the characteristic features of a particular pathogen,exotoxins and other aggressive factors.
Specific infections
These, for example, include tuberculosis, syphilis. These pathologies are somewhat different from others. It must be said that these infections have existed for a long time in humans and the body is somewhat "used" to them. As a rule, these pathologies are not accompanied by a vivid clinical picture. However, against the background of infections, specific inflammations develop, which can be seen through a microscope. These pathologies are very difficult to treat. In this case, treatment is aimed only at eliminating the clinical manifestations of the infection. Completely rid the body of specific diseases is not possible today.
Immune activity
The body's defense system includes two branches: cellular and humoral. The latter is necessary to create specific antibodies to the antigens of harmful bacteria. When a pathogenic microorganism enters, it is met by immune cells - macrophages. They destroy bacteria, studying their structure in the process. Then they transfer the received information to the central organs of the defense system. They, in turn, give a signal for the production of proteins (antibodies) that will have the ability to attach to bacteria and destroy them. The antibodies created are released into the bloodstream. Cellular defense of the body is built according to a different scheme. White blood cells attack foreign bacteria using proteolytic enzymes. Outwardly, they are pus. Thanks to the presenceof these enzymes, pus has the ability to dissolve surrounding tissues and break out, carrying foreign compounds with it.
The state of the body after therapy
Recovery of the body can be of three types: complete, laboratory or clinical. In the latter case, we are talking about the absence of any symptoms that relate to pathology. Laboratory recovery is established when there are no laboratory signs. A complete cure is a condition in which no harmful microbes are found in the human body that provoked the pathology. Of course, not all diseases end in recovery. In practice, a lot of cases and deaths have been registered. Also, the course of pathology can go from acute to chronic.
In closing
| Pathology | Pathogen | Center of localization | Distribution method |
| Diphtheria | Corynebacterium diphtheriae (gram-positive, rod-shaped bacterium) | Upper respiratory tract (pharynx, usually) | Airborne |
| Tuberculosis | Mycobacterium tuberculosis (rod-shaped microbe, belongs to the genus Actinomycete) | Mostly light | Airborne, through the milk of infected animals |
| Whooping cough | Bordetella pertussis (gram-negative, rod-shaped bacterium) | Upper respiratory tract | Airborne |
| Gonorrhea | Neisseria gonorrhoeae (gram negative coccus) | Genital organs (mainly mucous membranes of the urinary tract) | With sexual contact |
| Syphilis | Treponema pallidum (spirochete) | Genitals, eyes, bones, CNS, joints, skin, heart | With sexual contact |
| Typhoid | Rickettsia | Internal walls of blood vessels (blood clots), skin (rash) | Epidemic form - carrier of louse, endemic - rat fleas |
The above is a table. Human diseases caused by bacteria are briefly highlighted in the diagram.
