Department of Microbiology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781022, Assam, India.
Antigenic characterization of 12 classical swine fever (CSF) virus isolates from different places of Assam,India was done using polyclonal serum raised against cell culture adapted lapinized CSF vaccine virus strain and a field isoate of CSF virus.Both liquid phase blocking ELISA (LPB-ELISA) and neutralization peroxidase linked assay (NPLA) were standardized and used to detect the antigenic relationship of the field isolates with the vaccine virus and the field isolate. In LPB-ELISA, 50% inhibition log titre of the CSF virus field isolates ranged from 1.204 to 1.806 when tested with the vaccine virus antiserum raised in rabbit,whereas the log titre of the homologous vaccine virus was found to be 2.107.With the field virus antiserum 50% inhibition titre of the field isolates ranges from 1.204 to 2.107. Four of the field isolates showed the highest log titre of 2.107 similar to the homologous field isolate. In NPLA the neutralization titre of the CSF virus isolates ranged from 1.380 to 1.681 and 1.380 to1.982 with the vaccine and the field isolate antisera respectively. No significant difference was observed between the mean log titre of the field isolates by using the vaccine and the field isolate antisera in LPB-ELISA and NPLA. A significant positive correlation was observed between the mean titres obtained by LPB-ELISA and NPLA.
