Serological monitoring of cattle mycoplasmosis

Abstract

The results of studying the immune response with persistence of the microorganism of the genus Mycoplasma in the body of cows are presented. The study (2019) was conducted in dairy farms in five districts of Novosibirsk region. Identification of individual specific antibodies of class G to microorganisms of the genus Mycoplasma was carried out in 186 samples of blood serum of cattle. The study was carried out by enzyme immunoassay with the MycoplasmaIgG antibodies ELISA VET kit. In the majority of the studied farms, a prolonged persistence of the microorganism of the genus Mycoplasma was noted. It was found that mycoplasma, having weak immunogenicity, mainly causes a chronic course of the disease. In an enzyme-linked immunoassay, this phenomenon was recorded in dubious reactions in 60.8% of animals. In some farms during the study, a period of reactivation of the disease was noted, which appeared in the transition of the disease from the carrier phase to the active form with clinical manifestations. In the enzyme immunoassay, 7.5% of the animals reacted positively. It was noted that in farms with positively reacting animals, the probability of isolation and spread of the pathogen from sick animals is high. No reaction to the presence of class G antibodies to microorganisms of the genus Mycoplasma was detected in 31.7% of the animals studied. In most farms, the growth dynamics of animals with dubious response was noted to depend on their physiological period. The connection of the duration of cow lactation with the dubious antibody response in an enzyme-linked immunosorbent assay was established. The possibility of connecting this phenomenon with highly intensive use of productive animals, which leads to an increase in stress levels and a decrease in homeostasis and immunity, is shown.