Growth Characteristics Of Vaccinia And Camelpox Viruses In Embryonated Eggs And Cellculture And Their Detection By Polymerase Chain Reaction

Abstract

Camelpox virus isolates, VD45 (African camelpox strain) and Vaccinia virus were used for propagation in the chorioallantoic membrane of embryonated eggs (CAM). Lesions were seen as pocks ranging in size from 1 to 1.5mm in diameter, and they increase in size with serial passage and taking opaque- white and opaque-yellow colours. When propagated in Vero cells, these viruses gave clear CPE, characterized by rounding of cells, plaque formation, syncytia and detachment of cells from glass. Neutralization test was used as the method of diagnosis of camelpox virus in cell cultures, and two methods of DNA extraction were employed to conduct PCR to compare it with neutralization test. The first method of DNA extraction was accomplished by using viral DNA in CAMs and tissue culture supernatant, which was released by initial heating for 15 min at 99c° followed by ordinary PCR. In the second method DNA was extracted by using DNA Isolation Kit from tissue culture supernatant as a template. Rapid identification and differentiation of camelpoxvirus and Vaccinia virus were achieved by PCR and this assay proved to be fast and feasible, and can be an alternative to orthodox serological methods.