传染性支气管炎CK/CH/HD/190716株的分离鉴定与全基因组分析

Isolation and Identification of Infectious Bronchitis CK/CH/HD/190716 Strain and Genome-wide Analysis

对河北某免疫鸡场采集疑似感染传染性支气管炎病毒(IBV)鸡的肺脏进行病毒分离,并通过鸡胚接种和全基因序列测定分析,对分离病毒进行鉴定和遗传变异分析。分离到1株IBV,命名为CK/CH/HD/190716,该病毒接种鸡胚后可产生IBV特征性的侏儒胚。该病毒基因组总长为27680 bp,其中Ploy A尾含有16个A。将分离株基因序列与不同基因型的IBV毒株进行同源比对,构建遗传进化树进行基因分型,证实该毒株属于QX型。选取我国分离的14株QX型IBV与之比较同源性,发现该型病毒全基因组的同源性在93%~97%,但是5 a基因的同源性最低,只有80%,表明IBV各基因之间的进化具有显著差异。随后通过多个重组软件分析证实,该毒株的1 a基因部分区域由QX型野毒KX425847和KU317090重组产生。本试验揭示了我国流行的QX型IBV存在基因多样性,需要对该型病毒的遗传演化进行密切监测。

In this study,the virus was isolated from a chicken farm in Hebei provine.This chicken farm was vaccinated but was suspected with Infectious bronchitis virus(IBV)infection.After virus isolation,the virus was amplified in embryo and whole viral gnome was sequenced for virus detection and evolutionary mutation analysis.According to the results,one IBV strain was successfully isolated and named as CK/CH/HD/190716.This virus caused dwarf embryos,a characteristic of IBV infection.The length of the whole genome was 27680 bp,and its Ploy A tail contains 16 A.After comparing genome of this virus with other IBV strains,and building genetic phylogenetic tree,this virus was detected as a QX strain.The homology of whole genome of this virus and other 14 QX strains was between 93%and 97%,while the homology of 5 a was less than 80%,showing that there is significant difference between the evolution of different IBV genes.Thereafter,more recombination softwares were used to analyze the 1 a ORF of this virus and the recombination of KX425847 and KU317090.This study demonstrates the gentic diversity of IBV-QX is prevalent in China and intense monitoring is needed on the genetic evolution of QX.