The causative agent of tuberculosis - ways of infection and the survival of bacteria, prevention and treatment methods

Tuberculosis mycobacterium (tuberculosis mycobacterium), which provokes a fatal lung disease, is called Koch's bacillus. Infection can be transmitted by airborne droplets, localized and develops in the respiratory tract, affects the lungs and other internal organs. Not always manifested in active forms, requires medical supervision and timely treatment. It is useful to know at what temperature the tubercle bacillus dies, what are the features of the presence in the human body.

What is a Koch wand

A very dangerous disease is tuberculosis. Chronic disease affects the respiratory tract and contributes to the formation of foci of necrosis in the lungs with a fatal outcome for the patient. The causative agent from the external environment enters the body by airborne droplets, less often the source of infection is domestic animals (cattle). For a long time, the disease develops in a latent form, and is activated after a sharp decrease in the body's immune response. For example, there is a relapse after increased activity of infectious disease pathogens and their prolonged extermination.


From time immemorial, tuberculosis has been called consumption, and such a deadly disease has exterminated more than one generation of people of all ages. German doctor Robert Koch after numerous laboratory studies in 1882 discovered an elongated bacterium, which was later named in his honor. At the same time, another medical term appeared - the Koch Triad, relevant in identifying characteristic bacilli. The sequence of actions was as follows:

  • extraction of mycobacterium tuberculosis of increased virulence from the patient’s tissues;
  • growing and monitoring the bacterium;
  • infection of a healthy body (laboratory mice).

The size

Studying all existing types of mycobacteria (74 varieties), it is worth noting that the Koch wand has a protective shell and negligible size. The diameter of the bacillus reaches 0.2-0.6 microns, while its length is 1-10 microns. MTB colonies grow in a dense nutrient medium at a slow pace, while they differ in rough surface, weak pigmentation. More common pink-orange or milky. You can detect the stick in the secretions of sputum, which becomes biological material for further laboratory research.


Tuberculosis virus is a stick that, after staining the bacteria, was discovered by Robert Koch. Outwardly, it is an oblong stick of a straight or curved shape, which, after penetrating into a healthy human body, is distinguished by its reduced activity. Numerous laboratory studies of sputum under a microscope showed the design features of such a pathogenic microorganism, the following elements of Koch tuberculosis mycobacteria were identified:

  • multilayer cell walls that perform a protective function;
  • bacterial cytoplasm with granular inclusions;
  • nuclear substance with one circular DNA;
  • membrane of the cytoplasm.


A feature of Koch's stick is the method of reproduction - airborne or vegetative. The division cycle lasts a day, but environmental factors, such as dampness, humid air, can affect this process. Since the dangerous bacillus has been producing for several centuries, its viability is significantly increased, resistant to the antibiotic. The pathogen enters the respiratory tract, where it multiplies under the influence of provoking factors. After the multiplication of mycobacteria and the spread of infection, the risk of mortality increases, which threatens the human body.

How long does Koch’s wand live?

You can become infected with tuberculosis from the environment, and the life span of a microbe depends entirely on its living conditions. For example, the viability of a Koch stick in manure is 15 years, while in the dried state, mycobacteria dies after 5 years. If you fight with mycobacterium tuberculosis by boiling, the death of the pathogenic microorganism occurs after 15 minutes. When malicious Koch bacilli are detected, freezing will not help to exterminate the pathogenic flora.

How dies

The tuberculosis (Koch) bacterium is exposed to direct radiation, for example, during chemotherapy. In such a clinical picture, it turns into an L-shape and lasts for decades. The same thing happens with strong immunity. In damp rooms, it maintains its viability for many years, and at high temperature it loses its former activity, quickly dies.

What kills the wand

There is a high resistance of mycobacteria, therefore, disinfection in such a clinical picture does not provide positive dynamics of the underlying disease. You need to know what can cause massive death of pathogenic flora in order to be treated on time after contact with a sick person. In the presence of mycobacteria, this is what they can destroy in the shortest possible time:

  • ultraviolet radiation (2-3 minutes);
  • sun rays (60-90 minutes);
  • boiling water (15 minutes);
  • drying (25 minutes);
  • the presence of chlorine in the disinfection (5 hours).

Tuberculosis transmission routes

The carriers of the sticks are infected people (sputum of the patient), less often - food, water, livestock (with milk). The infection process occurs by airborne droplets, upon contact. Microbes penetrate the respiratory tract. It is important to know what causes tuberculosis in order to comply with prevention rules. The disease progresses with the body's resistance, and the preconditions are bad habits, psychosomatic diseases, immunodeficiency states, age-related changes, social and environmental factors. Tuberculosis is transmitted through the blood of an infected person.

Methods for the diagnosis of tuberculosis

The vaccination schedule necessarily includes the performance of the Mantoux test, which is indicated for adults and young children by age. In this way, the reaction of the body to tuberculin is determined, and if the answer is yes, the patient is on a medical check-up, needs regular examinations to observe the growth of the stick.

Since the Koch bacillus penetrates the lungs and infects once healthy tissues, fluorography is required for tuberculous lesions. Such a clinical examination is not able to determine the types of mycobacteria, but it clearly reveals the existing forms of tuberculosis. In the presence of dangerous forms of the disease, course administration of anti-TB drugs is necessary. A patient with pulmonary tuberculosis additionally shows a sputum test to understand the types of sticks that can cause relapse.

Tuberculosis immunity

The causative agent of tuberculosis is fatal to the body, and prevention is necessary to completely eliminate its activity. In order not to get infected, BCG vaccination is shown, according to the vaccination schedule. If symptoms of tuberculosis have already appeared, Koch's wand slowly destroys lung tissue, the patient allocates free time and goes to the doctor for a diagnosis.

By the method of infection with Koch bacillus, therapeutic measures can be determined, and with additional clinical studies, lymph nodes should be evaluated. To reduce the spread of the pathological process, it is important to trust your health with the medicine prescribed by your doctor. He considers it necessary to take immunostimulants and the use of anti-TB drugs.

Attention! The information presented in the article is for guidance only. Materials of the article do not call for independent treatment. Only a qualified doctor can make a diagnosis and give recommendations for treatment based on the individual characteristics of a particular patient.

Watch the video: Mycobacterium tuberculosis infection and diseases (February 2020).