Comparing the serotype and genotype of local isolates of IBV from Shandong and Beijing by RFLP

Isolated and Identified IBV 5 local isolates (A,B,C,D from Shandong and F from Beijing), Cross neutralization tests were performed in tracheal organ cultures(TOC)to compare the serotype of IBV M 41 ,T and those isolates. The result of serotyping showed that A and T, B and D, F and 4/91 were the same serotype. A pair of primers of S1 gene to those IBV local isolates were designed according to strain M 41 (Gene Bank NO. M21883). S1 genes of them were amplified by RT PCR. PCR products were digested with restriction endonuclease HaeⅢ, and the RELP results showed that A, C, D, M 41 shared the same RFLP pattern, there were 900?400 and 300bp segments, whereas F or B had different RFLP pattern. A, C, D, M 41 were genotype of Mass; F was alone, there were 1000?300?200 and 100bp segments. There were 700?500?300 and 180bp segments in B, B maybe share with genotype of T in theory; The results of serotype and genotype showed maybe some difference in them.