Modeling experiments on animal models of tuberculosis
Modeling experiments on animal models of tuberculosis
In recent years, tuberculosis has again become a public health problem of global concern. According to the World Health Organization, about 2 million people die of tuberculosis and 8 million new cases occur globally every year. According to the results of the 2000 epidemiological sample survey, there are 4.5 million tuberculosis patients in China, and about 180,000 tuberculosis patients die every year. Therefore, experts and scholars from various countries have carried out basic research on new vaccines. The establishment of animal models of pulmonary tuberculosis is the basis of tuberculosis research, and various new vaccines also need animal models to do relevant evaluation.
Principle
The basic principle of tuberculosis animal model modeling experiments is that Mycobacterium tuberculosis infection in vivo usually causes three kinds of pathological changes in the tissues of the organism: exudation, necrosis or hyperplasia, and depending on the reactivity of the organism (including immune response and metamorphosis), the amount of bacilli, virulence, and the different tissue characteristics, different types of pathological changes can occur.
Operation method
Modeling experiments on animal models of tuberculosis
Principle
The basic principle of tuberculosis animal model modeling experiments is that Mycobacterium tuberculosis infection in vivo usually causes three kinds of pathological changes in the tissues of the organism: exudation, necrosis or hyperplasia, and depending on the reactivity of the organism (including immune response and metamorphosis), the amount of bacilli, virulence, and the different tissue characteristics, different types of pathological changes can occur.
Materials and Instruments
Equipment: Move The basic procedure for modeling tuberculosis can be divided into the following steps: For more product details, please visit Aladdin Scientific website.
① Injection;
② H37Rv standard strain;
③ C57BL/6 mice, etc.
Reagents:
① Tween 80 physiological saline.
A. Mice: C57BL/6 mice, 6-8 weeks old, weighing (18±2) g. The standard strain of H37Rv, which was recovered from in vivo virulence in mice, was transplated in modified Roche medium and incubated at 37 ℃ for 20 days.
B. Dry colonies with good growth were scraped and ground, and the bacteria were ground into a 1 mg/mL bacterial suspension by adding 0.05% Tween 80 and physiological saline. B. Scrape and grind the well-grown dry colonies, add 0.05% Tween 80 saline and grind them into 1 mg/mL bacterial suspension, each milliliter of suspension contains about 1x107 cfu of viable bacteria per milliliter of H37Rv.
C. Inoculate the bacterial solution into Roche medium and determine the concentration of the bacterial solution at 1x107 cfu/mL after 20 days of incubation. 0.2 mL of the bacterial solution was injected into mice via tail vein.
D. At the third week, pathological changes of varying degrees of infection were seen, and most of alveolar cavities were filled with predominantly neutrophils. D. At week 3, pathological changes of varying degrees of infection were seen, with most alveolar cavities filled with inflammatory exudate and necrotic tissue, mainly neutrophils, with obvious caseous necrosis in the center of the lesion, and in some cases pulmonary edema and emphysema, and the lesions involved about 2/3 of the lung tissue.
E. At week 6, large, medium-sized, and small tuberculous nodules and lamellar confluent foci were seen with caseous necrosis and pulmonary edema, and the extent of the lesions was mostly over 2/3 of the lung tissue. At the 9th week, in the group with tail vein infection, there were more fused foci of tuberculosis and a certain amount of alveolar macrophage hyperplasia, and the extent of the lesion was more than 3/4. After antacid staining, different numbers of Mycobacterium tuberculosis were positive under the microscope.