The Phylogenetic Analysis Of IBV In Shandong Provinc And Development Of TaqMan One-step Fluorescence QRT-PCR Assay For Detection Of IBV?NDV And AIV H9

Infectious bronchitis is an acute,highly contagious disease which was caused by Infectious bronchitis virus.Currently,the disease was mainly prevented by attenuated li ve vaccine.However,due to various reasons,IBV was not be controlled effectively.Huge economic losses to the aquaculture industry were caused by immune failure.Th erefore,it was important for guiding clinical diagnosis by developing epidemiological studies and establishing an efficient,rapid diagnostic method of IBV.2014-2015,115 clinical samples which were sent from Shandong around were de tected,while,15 samples were determined for IBV.In order to understand the variati on of IBV,the phylogenetic analysis of 11 plants were analyzed.It was showed that11 Shandong IBV isolates belonged to two genotypes: QX and H120 genotype,in wh ich 10 belonged to QX genotype.It was showed that QX genotype was Shandong pr evailing dominant one.By analyzing S1 gene sequence,four clades were formed by11 isolates and reference strains at home and abroad.In addition SD1411-8 Y2,S D161 Y5 belonging to H120 strain as the representative of clades III,the remaining9 strains belonged to QXIBV as the representative of clades I.Through analyzing M gene sequence,10 isolates of IBV strains were in order as the representative of the QX clade?,while,SD1411-8 Y2 isolates and vaccine strains H120,Ma5 constituted clade III.By analyzing N gene sequence,11 isolates were sentenced QXIBV as th e representative of the branch I.It was showed that the S1 gene's mutation was higher than M,N gene,at the same time,the M gene conserved than N gene.In t his study,combined with three main virulence genes,Shandong major pandemic strain was determined,wherefore errors caused by single determination of virulence genes were avoided.The clinical symptoms and relevant information showed that: most of the time w hen farms infected pathogenic avian infectious bronchitis,there will be also infected with other pathogens,such as Newcastle disease virus and avian influenza virus.In o rder to detect and distinguish Avian infectious bronchitis virus,Newcastle disease vir us and avian influenza H9 virus which had similar symptoms quickly and effectively,a triple fluorescence quantitative RT-PCR was established.Through testing repeated experiments,this method was feasible.This method could distinguish these three pat hogens specificly with various other pathogens as control.Sensitivity tests showed th at a 10-7 dilution positive allantoic fluid could be detected by this method.