| Infectious Bronchitis(IB) is a severe acute respiratory disease of pouLtry, caused by Infectious bronchitis virus (IBV)。Since broke out in USA in the 1930s, IB have been an important disease of poultry around the world. IBV is a sRNA virus,the gene of the virus always mutated owing to it's point-mutation and gene recombination, so the virus have many serotypes. The known serotypes can be classified into respiratory symptomatic serotypes such as Conn, Iowa97, JMK, Florida, Arkansas99 and nephritic symptomatic serotypes such as M41, Holte, Gray, Australia'T'.Gough reported a new serotype of IBV named 793/B (also known as 4/91 and CR88) in UK in 1992,793/B isolates have not any or a little serological relation with other serotypes of IBV, the whole S1 gene of 793/B isolates differed by 21% to 25% from those of other 17 European isolates. In recent years, the 793/B serotype of IBV, harmfuL to the healthy development of pouLtry breeding, prevailed and spread in Spain, Germany, Holland, Italy and Thailand, too.Youxiang Diao, Jiehua Yang et.al.(2003) isolated an IBV 793/B strain named IBV TA03 from layer flock in a chicken house of Shandong province. On the basis of that, an IBV 793/B RT-PCR detective method was established and elementarily applied, furthermore, S1 gene of IBV 793/B TA03 strain was successfully cloned and expressed.According to the sequences of the 793/B serotype of IBV S1 gene published in GenBank, a pair of primers was designed and synthesized to specifically amplify a 891bp nucleotide fragment, the RT-PCR technique to detect the 793/B serotype of IBV was established. The 891bp special strip was found only in the PCR amplification of the 793/B serotype of IBV in the specificity assay, there were no the same strip appeared in the other viruses and strains of IBV. The sensitivity result indicated that as little as 10pg of... |
