SU1046281A1 - Method for determining virulence of mycrobacteria of tuberculosis - Google Patents

Abstract

METHOD FOR DETERMINING THE VIRULENCE OF MYCOBACTERIA TUBERCULOSIS by infecting guinea pigs with the mycobacterial culture under the hard shell of the hungry brain with subsequent consideration of organ damage, characterized in that, in order to speed up the method, the occurrence of hind limbs paralysis and after paralysis up to 19.2 days after infections determine a high degree of virulence, at 19.3-24.1 days - an average degree of virulence and at 24.2-30 days - a weak degree of virulence. § (L

Description

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The invention relates to microbiology and can be used for bacteriological examination of tuberculosis patients. . A biological method is known for determining the virulence of mycobacterium tuberculosis; it is envisaged that the experimental animals are infected with the tuberculosis pathogen intramuscularly, intravenously, intratascularly or aerogenically, after which animals are observed for 3-5 months until their death, followed by necropsy, assessment of lesion of the urenous organs, the secretion of microbacteria from the organs and, on the basis of this, a conclusion about the virulence of the causative agent Cl.

However, this method is complicated and is characterized by low efficiency of research, which leads to a decrease in the effectiveness of anti-epidemic measures and lengthens the duration of treatment of patients.

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There is also known a method for determining the virulence of mycobacterium i tuberculosis by infecting guinea pigs with a culture of myosobacteria under the dura mater of the brain with subsequent consideration of organ damage 21.

However, the known method for determining virulence is also characterized (it is very complex and its duration is due to the large number of parameters taken into account.

The purpose of the invention is the acceleration of the method.

The goal is achieved by the fact that, according to the method for determining the virulence of mycobacterium tuberculosis, including the infection of marine piglets with the mycobacterial culture under the dura mater of the brain and the subsequent recording of organ damage, the occurrence of paralysis of the hind limbs is taken into account, and for paralysis up to 19.2 days after infection, there is a high degree of virulence, the average degree of virulence for 19.3-24.1 days and a weak degree of virulence for 24.2-30 days. I

Example. Contamination of marine

pigs weighing 250-450 g are produced in a dose. 0.1 mg wet weight. Suspension of the culture is prepared by thoroughly rubbing the last in a mortar with the gradual addition of sterile saline, until the suspension reaches a concentration of 1 mg / ml. Each strain was tested on four guinea pigs of approximately the same weight.

Infection of animals is carried out as follows. In the region of the parietal hillock above the eye socket to the right of the midline of the skull, the skin is removed from the hair and plucked out. Having previously given deep anesthesia and having treated the place of operation with alcohol, they make a skin incision of 1.0-1.5 cm in size, 0.5 cm to the right of the midline and 3 cm up from the posterior ocular line. The skin wound is expanded with a scalpel, the periosteum is cut and carefully prepared, then dried with a sterile swab. To the right of the median plane, in order not to damage the longitudinal venous sinus with the help of a conical fissure bur, drill out the deepening, which does not penetrate into the cavity of the skull. Infectious material in a volume of 0 ml was injected directly under the solid membrane of the brain. To do this, the last one is pierced in the recess made with a needle of the syringe and immediately, having lowered the syringe horizontally, move the needle sideways 1 cm and outward under the shell and slowly inject the suspension. The needle is withdrawn from the cavity by a rapid movement, which prevents leakage of the introduced material. In order to prevent the outflow of blood or CSF, the hole in the skull bone is pressed for 5-10 seconds with soft tissues. The wounds are tightened with ligature sutures using a normal surgical needle, which is then smeared with iodine or cleol.

After infection, the pigs are placed in a cage and once a day I evaluate: their condition. When paralysis of the hind limbs occurs, paralysis of the mumps is removed from the cell and clogged by creating an air embolism, registering the number of days from the moment of infection to the appearance of paralysis. If, after a month after infection, all or part of the pigs do not develop paralysis, they are also killed, considering that Paralysis has developed on the thirtieth day.

Estimation of the degree of virulence by the average geometric term for the occurrence of paralysis is presented in the table,

The average period of virulence laziness paralysis days

Very high high average weak

Very weak At least 27.1

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The use of the proposed prototype makes it possible to reduce the operation time by a factor of 3-5 compared with the observation of experimental animal stomachs and by 2 times the volume of research.

Claims (1)

METHOD FOR DETERMINING VIRULENCE OF MYCOBACTERIA TUBERCULOSIS by infection of guinea pigs with a mycobacteria culture under the hard shell of a hungry brain followed by organ damage, characterized in that, in order to accelerate the method, the appearance of hind limb paralysis is taken into account, and if paralysis occurs up to 19.2 days after infection, it is determined a high degree of virulence, at 19.3-24.1 days - an average degree of virulence and At 24.2-30 days - a weak degree of virulence.