S-30. Polypeptide profile of Swinepox virus indigenous isolate

The swinepox virus is the prototype member of the suipoxvirus under the family Poxviridae which generally affects young piglets. The disease has a world wide distribution and is endemic to areas of intensive swine production. Polypepetide profile and DNA-RFLP serves as epidemiological tool in comparing closely related pox virus isolates and authenticate classification. The present study was intended to characterize polypeptide profile of indigenouss winepox virus isolate. For this, the swinepox virus isolate was passaged and propagated in porcine kidney cells (PK-15). The virus gave a maximum titre of 7.32 log₁₀ TCID₅₀/ml at 20^th passage. The cell culture propagated virus antigen was confirmed by AGID test using known positive anti-sera. The bulk cultivated swinepox virus in PK-15 cells was concentrated by ultracentrifugation and purified on linear potassium tartrate density gradient. The relative purity of virus was ascertained and the buoyant density was estimated to be ∼1.252. Polypeptide analysis of the purified swinepox virus was carried out on 10% SDS-polyacrylamide gel electrophoresis. The purified virus revealed around 20 structural polypeptides as resolved on 10% SDS-PAGE gel ranging from 15.4 KDa to 98.9 KDa. Six darkly stained virus polypeptides of MW: 66, 61.7, 56.2, 38, 21.3 and 18.4 KDa were presumed to be the major structural polypeptides of the virus. Out of the 20 polypeptides; 5 were low MW below 30 KDa, 6 between 30 to 50 KDa, 5 ranged from 50 to 80 KDa and 4 were of higher MW above 80 KDa. The polypeptides above 100 KDa could not resolve well. The polypeptide profile of purified swinepox virus would help to compare/differentiate between various swinepox virus isolates and other closely related pox viruses. Further, linear potassium tartrate density gradient ultracentrifugation was found useful for purification of cell culture propagated swinepox virus.