BIOCHEMICAL AND MOLECULAR GENETICS DISTINCTION AMONG SHEEP POX VIRUS STRAINS

Abstract

This study was planned to investigate SPV strains in order to choose the most suitable strains for vaccine production which will give e a good immune response for controlling the circulating virus in Egypt. For this purpose, the following experiments were done: propagation of ESPV strain on Vero cell for 18 passages, RSPV strain for 8 passages and KSPV strain for 13 passages the CPE was clear and completed after (5, 5 and 6) DPI for Egyptian, Romanian and Kenyan strains respectively. Titrations of SPV strains were 5.5, 5.2 and 6.3 TCID 50/ml for Egyptian, Romanian and Kenyan SPV strains, respectively. Concentration of virus to 1/10 from its size to prepare antigen of SPV to each strain. Hyper immune serum was used in western blot as a polyclonal antibody which reacts with nitrocellulose membrane. Sodium dodcyl sulphate-poly acrylamide gel electrophoresis revealed that there are similarity in molecular weight between Egyptian and Romanian strains were estimated by comparing their electrophoreses mobilities with those of known standard molecular weight marker after electrophoresis in the same gel following staining by coomassie blue stain the M.W of Egyptian and Romanian strains (172, 155, 128, 91, 72, 52, 40, 30, 29, 17, 15, and 13 kDa). But there are differentiating between them and Kenyan strain which M.W is (130, 50, 40, and15 kDa). Western blotting technique from this test concluded that there is relationship in immune response between Egyptian. Romanian which immunogenic protein fractions were ESPV and RSPV (67, 34, 32, 26) kDa KSPV (100, 75, 67, 49 kDa). From this result the RSPV is a best strain for vaccine production which gives high immune response for sheep pox. Polymerase chain reaction (PCR) revealed that no difference between three strains which have a similar positive reaction from these results we conclude that RSPV have close relation ship with ESPV