TUBERCULIN FOR ALLERGIC DIAGNOSTIC OF ANIMAL’S TUBERCULOSIS

The article discusses the problems of allergic diagnosis of tuberculosis in cattle, associated with nonspecific reactions in animals in safe farms and insufficient detection of sick individuals in tuberculosis-affected areas. The authors propose an improved and more affordable method for producing tuberculin based on alcohol precipitation of specific proteins from Mycobacterium bovis(BCG) culture fluid. The culture was grown on a Honeycomb medium, the biomass was processed using triton X-100, after which ultrafiltration with protein clipping up to 15 kDa and subsequent ethanol precipitation at 4 °C. The resulting precipitate was homogeneous, with a predominant protein mass of about 35 kDa. The protein concentration in the final preparation was 1 mg/cm3. The biological activity and specificity of the obtained drug were evaluated in a comparative test on guinea pigs sensitized with live cultures of M. bovis and M. Tuberculosis (BCG). Tuberculin was administered intradermally in the groin area at a dose of 25 IU, in parallel with commercial PPD-tuberculin. In the first group of animals sensitized with M. bovis, the reaction to the original drug was comparable to the reaction to PPD, followed by a decrease after 48 hours. In the second group, sensitized by M. tuberculosis, the reaction to the studied tuberculin was less pronounced, which indicates a higher species specificity of the drug. Thus, the proposed technology makes it possible to obtain a more specific and standardized tuberculin, which makes it promising for improving the accuracy of allergic diagnosis of tuberculosis in farm animals.