STRAIN DIFFERENTIATION OF FOOT-AND-MOUTH-DISEASE VIRUS TYPE ASIA-1

Foot-and-mouth disease(FMD) virus isolates (20) of serotype 'Asia 1' i solated from outbreaks during 1987-92 from different parts of India we re analyzed to assess their relationship with the Asia 1 vaccine strai n virus in micro-complement fixation test (CFT), sandwich enzyme-linke d immunosorbent assay (ELISA) and 2-dimensional micro-neutralization t est (2D-MNT) using anti-146S guineapig serum raised against the vaccin e strain virus. In micro-CFT the relationship (r value) of the field i solates with the vaccine strain virus ranged from 0.5 to 0.75. In sand wich ELISA, 11 isolates showed r values in the range of 0.75 to 1.00, 7 isolates gave r values of 1.00 range of 0.50 to 0.74 and 2 isolates gave somewhat lower r values (r=0.44). In 2D-MNT, 11 isolates gave r v alues of 1.00 and remaining 9 isolates gave r values between 0.51 and 0.91. All the field isolates were thus related to the vaccine strain v irus. There was no significant difference between r values obtained wi th sandwich ELISA and 2D-MNT.