DIAGNOSTIC SIGNIFICANCE OF SEROCONVERSION TO MANNHEIMIA HAEMOLYTICA LEUKOTOXIN IN CATTLE
The serum antibody levels to antigens of Mannheimia haemolytica, leukotoxin Mannheimia haemolytica and Pasteurella multocida were studied in calves infected with bronchopneumonia using ELISA. Nasal mucus was studied for presence of the genome of causative agents of pasteurellosis and virus pathogens using the polymerase chain reaction. Seroconversion to M. haemolytica and M. haemolytica leukotoxin was demonstrated in serological tests. The genome of causative agents of pas-teurellosis was not detected using PCR test system. Herewith, the genome of coronaviruses and pathogens of bovine viral diarrhea was detected. The results of the experiment suggest the diagnostic significance of seroconversion to M. haemolytica leukotoxin.