DefinePK

Abstract

Lumpy skin disease (LSD) causes the death and premature culling of animals, resulting in great economic losses in animal husbandry practice. The primary methods for preventing its spread are the vaccination of susceptible livestock and timely and accurate diagnoses. Considering the high risk of LSD virus (LSDV) spread in Kazakhstan, the development of a sensitive and specific enzyme-linked immunosorbent assay (ELISA) would be crucial in ensuring the veterinary safety of the country. Thus, in this study, we developed an indirect ELISA based on the P32 antigen of LSDV for the serological diagnosis of cattle and evaluated its effectiveness. In this indirect ELISA, recombinant P32 (rP32) protein was used, which was produced using the DNA of an LSDV isolated from Kazakhstan. The protein was purified using metal affinity chromatography and examined using a mass spectrometer. The optimal concentrations of rP32 for immobilization on the plate were observed to be 0.6 and 0.3µg/mL. The serum dilutions with the lowest background values were 1:400 and 1:200. As a blocking buffer, 3% skimmed milk in phosphate-buffered saline-Tween (pH 7.4) was used. Secondary antibodies were used at a dilution of 1:20,000. In studies using an in-house P32/ELISA, 71% of bovine serum samples that were collected 28d after vaccination tested positive. Overall, the indirect ELISA showed high potential for epizootological monitoring and mass screening of animals vaccinated with a domestic vaccine. However, to obtain more reliable results, continuing this study using a larger number of serum samples from vaccinated cows is necessary.