摘要
An enzyme-linked immunosorbent assay using the expressed protein σ B as the coating amigen (σ B-ELISA) for detecting antibody to avian reovirus (ARV) in chickens was developed and compared with a conventional ELISA. Both ELISAS and a serum neutralisation (SN) test were used to test the sera from experimentally vaccinated and farm chickens. The σ B-ELISA could clearly distinguish the SN-positive and -negative sera in 38-week-old chickens. The correlation rate between SN and a σ B-ELISA was 100 per cent (65/65), and that between SN and conventional ELISA was 84 per cent (55/65). With the σ B-ELISA, all SN-negative sera had low absorbance values (below 0-06), and the absorbance values correlated closely with the SN titres. However, the sera which were antibody-negative by SN had various absorbance values, ranging from 0·07 to 0·39 in the conventional ELISA. Hence, the σ B-ELISA had lower non-specific binding reactions than the conventional ELISA against sera from ARV-negative birds. Antibody against ARV could be detected by σ B-ELISA after vaccination. Absorbance values peaked 4 weeks after vaccination at 2 weeks of age and were maintained until the birds were 27 weeks old. The results suggest that the presence of antibody against viral protein σ B in birds may be used as a good indicator by the σ B-ELISA for detecting immune status of a chicken flock or to detect chickens infected with ARV. © 2000 Harcourt Publishers Ltd.