THE IMPORTANCE OF PCR IN THE INFECTIOUS AGENTS DETECTION IN CATTLE

The aim of our work was to identify bacterial and viral infectious agents in biological material from cows and calves with different clinical manifestations of diseases by PCR. Biological materials from animals were sent to the PCR laboratory from 23 agricultural organizations in the Ural Region. A total of 808 samples were studied, of which genomes of pathogens were found in 11.9 % of cases: Mycoplasma bovis DNA in 2.4 % of samples, Bovine virus diarrhoea RNA in 2.3 % of samples, Mycoplasma spp. and Chlamydia spp DNA in 2 % of samples, Mycoplasma bovigenitalium, Bovine herpesvirus (type 1), Chlamydophila abortus, Chlamydophila pecorum were found singly. Out of 80 samples in 36.2 % of biomaterials, specific DNA sites of Cl. difficile were found – 31.2 % of samples, Cl. perfringens – 20.0 % of samples, Cl. difficile + Cl. perfringens – 25.0 % of biosamples. Toxins were found in Cl. difficile: CDT toxin in 41.0 % of clostridia, toxin B in 6.0 % of pathogens, less often toxin A. In some cases, clostridia (Cl. perfringens, Cl. difficile B) were found in the biomaterial from dead calves, which confirmed the diagnosis – infectious anaerobic enterotoxemia of calves. Bacteria (E. coli, Salmonella enterica spp. entericaserogroup C (0:9, 2), Cl. perfringens and Cl. difficile CDT DNA) were detected in the biomaterial from dead cows, which confirmed the diagnosis of acute intestinal infection. All detected pathogens were presented in the form of monoinfection and singly in the form of mixed infections. Using PCR, it was possible to detect DNA and RNA of infectious agents in various clinical manifestations of diseases of bacterial and viral etiology in cattle herds in the Ural Region.