The thesis is devoted to study of the epizootic situation of paratuberculosis in farm and wildlife ruminants around the world (2010–2017) and analysis of the epizootic situation regarding paratuberculosis in cattle on Ukrainian farms (2008–2017). From biological material, collected from cattle and samples of faeces of zoo animals, epizootic culture of Mycobacterium avium subsp. paratuberculosis (MAP) was isolated. Tinctorial, cultural-morphological, biochemical and biological properties of selected MAP cultures were studied. Selective nutrient medium for cultivating MAP, a specific paratuberculosal antigen and a positive serum for a complement-fixation test were developed as a domestic diagnostic tools.
The presence of paratuberculosis infection worldwide has been established according to the study results on the epizootic situation in 2010–2017. The clinical manifestation of paratuberculosis infection was recorded in 30–40 (12.4–16.6%) countries around the world. At the mentioned time, 56–69 (23.3–28.6%) countries were recognized as countries free from the paratuberculosis. Sporadic cases of MAP infections on localized areas were registered in 9–14 (3.7–5.8%) countries. Paratuberculosis was distributed is 23 (43.4%) European countries, 12 (22.6%) countries were free from paratuberculous infection and 13 (24.5%) did not report about the presence of contagious agent on their territory. Diseases were registered in 7–12 (2.9–5.0%) countries among wild ruminants around the world.
The retrospective analysis of the epizootic situation regarding paratuberculosis in Ukraine (2008–2017) was performed. According to the results of this analysis it has been established that the MAP pathogens was identified while bacterioscopical examination of fecal samples from cattle on one farm. In 2016–2017 53 positive results were obtained according to the serological testing of blood serum from cattle with the use of complement-fixation test (CFT).
The circulation of MAP infection in cattle on one farm of Khmelnitsky region and in zoo animals (Lama lama, Camelus bactrianus, Elaphurus davidianus, Bos frontalis frontalis) has been established. In mycobacteria, obtained from biological samples and feces, a tinctorial, cultural-morphological, biochemical and biological properties were studied. In addition, it caused the development of pathological process on 1-months old rabbits. The animals died 42–89 days after infection.
During the experiments a selective synthetic nutrient medium for cultivation of MAP was developed. It was established that the developed synthetic nutrient medium provides the growth of MAP culture during cultivation. The accumulated bacterial mass is 25.0 ± 1.6 g/l (р < 0.01), and the mass of bacterial protein in the nutrient media is 7.85 ± 0.29 g/l (р < 0.01).
The strain M. avium subsp. paratuberculosis Demetra was obtained by the selective method of cultivation. This strain can be used in the production of specific paratuberculosis antigen. The optimal cultivation term for the strain MAP Demetra is 70 days on the synthetic nutrient medium.
The immunization scheme for laboratory animals was performed. It consists of three times subcutaneous injection of inactivated bacterial mass of MAP strain Demetra at the concentration of 20.0, 30.0, 30.0 mg/cm3 with sterile liquid paraffin. The intervals between injections are 7 days. As the result of this part of research the positive serum for diagnosis of paratuberculosis infection in cattle was obtained in dilution 1:400.
It is proved that an antigen, produced from a culture filtrate from the strain M. avium subsp. paratuberculosis Demetra, is an active (1:700) and highly specific (100.0%) diagnostic agent. Antigen, diluted in the working titer, detects specific to MAP antibodies in the blood sera of infected and immunized by MAP animals in dilutions of 1:10 and 1:20. At the same time, it does not react with heterologous blood sera from animals sick with tuberculosis, leukemia, brucellosis, chlamydia, yersiniosis, salmonellosis and sensitized by atypical mycobacteria form animals in the complement fixation test.
