2020-2021年我国部分省份禽呼肠孤病毒分子流行病学调查

Molecular Epidemiological Investigation on Avian Reovirus in Some Provinces of China from 2020 to 2021

近年来,禽呼肠孤病毒(ARV)在我国白羽肉鸡群中的感染率呈上升趋势,流行范围较广,给我国肉鸡养殖企业带来了较大经济损失。ARV易变异重组,因此全面了解其分子流行病学特征具有十分重要的意义。为了解我国白羽肉鸡群中ARV的遗传变异特点,2020—2021年从山东、河北、福建、安徽、辽宁、江苏等6个省份收集疑似ARV感染样品,采用RT-PCR方法筛选阳性样本,然后对阳性样本进行σC基因(1088 bp)测序,根据测序结果分析ARV不同基因型分布规律及占比。结果显示:2020—2021年,从6个省份中,经RT-PCR检测,检出ARV阳性样品157份,总阳性检出率为62.1%,不同省份的阳性检出率为44.4%~77.3%。157份阳性样品可分为6个基因型,其中基因1型61份(38.85%)、基因2型41份(26.11%)、基因3型15份(9.56%)、基因4型9份(5.73%),基因5型30份(19.11%),基因6型1份(0.64%);61份基因1型样品中,38份与标准ARV疫苗株(S1133)属于同一亚分支,另外23份与4599参考株处于单独的另一亚分支。结果表明:我国肉鸡群中存在一定程度的ARV流行;流行的ARV基因型较为复杂,且存在基因1型变异毒株,当前的疫苗株已不能对其提供足够的保护。结果提示,今后需要进一步开展ARV感染监测,评估其流行及变异情况,调整免疫策略,加快新疫苗等防疫技术及产品研发。本研究初步了解了我国部分省份的ARV分子流行病学特征,对我国ARV感染的防控具有重要意义,也为变异株新型疫苗研发提供了依据。

In recent years,avian reovirus(ARV)has been increasingly and widely prevalent in white feather broilers in China,bringing great economic losses to broiler breeding enterprises in China.As ARV is prone to mutation and recombination,it would be of great significance to comprehensively investigate its molecular epidemiological characteristics.In order to investigate the genetic variation characteristics of ARV in white feather broilers in China from 2020 to 2021,253 suspected ARV infected samples were collected from Shandong,Hebei,Fujian,Anhui,Liaoning and Jiangsu provinces to detect positive samples by RT-PCR,followed byσC gene(1088 bp)sequencing,against which,the distribution and proportion of different ARV genotypes were analyzed.The results showed that 157 positive samples were detected by RT-PCR,with a total positive detection rate of 62.1%,and that in each province was from 44.4%to 77.3%.All the 157 positive samples were divided into 6 genotypes,including 61 genotype 1(38.85%),41 genotype 2(26.11%),15 genotype 3(9.56%),9 genotype 4(5.73%),30 genotype 5(19.11%),and 1 genotype 6(0.64%);38 out of 61 genotype 1 samples belonged to the same sub-branch as the standard ARV vaccine strain(S1133),and the other 23 fell into a separate sub-branch with 4599 reference strain.In conclusion,ARV was prevalent in broilers in China to certain extent;the prevalent ARV genotypes were complex,and there were genotype 1 variant strains,so sufficient protection could not be provided by current vaccine strains anymore,which indicated that surveillance for ARV infection should be further strengthened,its prevalence and variation should be evaluated,immunization strategies should be adjusted,and research and development of disease prevention technologies and products such as new vaccines should be accelerated.The above study on the molecular epidemiological characteristics of ARV in some provinces of China supported the prevention and control of ARV infection in China,and provided a basis for the research and development of novel vaccines against any variant strains.