Isolation and identification of avian infectious bronchitis virus.

[Objective] The aim was to isolate and identify avian infectious bronchitis virus (IBV) from diseased chickens.[Method]IBVs were isolated from the diseased chickens in a chicken farm in Anhui Province with blind passage method to observe virus pathogenicity. Then animal regression test was made to replicate symptoms of bronchial congestion in SPF chickens and S1 gene segments were amplified and isolated, followed by comparison with IBV vaccine strains. [Result] Detection of Hemagglutinating activity (HA) showed that allantoic fluid had no concerning effect on erythrocyte, suggesting that NDV and AIV were not included in the isolated viruses. However, the erythrocyte could be agglutinated with allantoic fluid treated with 1% of pancreatin, which is in consistent with biological characters of IBV. After SPF chickens were inoculated with the 6th SPF allantoic fluid, bronchial congestion was replicated, proving that the isolated virus was avian IBV, named IBV XZ strain. [Conclusion] This study provides a theoretical basis for prevention of avian infectious bronchitis.