中国4省猪场猪盖他病毒感染调查及病原分离鉴定

Molecular Detection,Isolation and Identification of the Porcine Getah Virus from Pig Herds in Four Provinces,China

为了解我国猪盖他病毒（Getah virus,GETV）流行情况,本研究利用RT-PCR和病原分离方法在国内首次对晋、冀、豫、皖4省231个猪场的801份猪脏器和组织进行GETV的病原学调查及部分基因序列分析。试验结果显示,从4省的猪群样品中均检出GETV,其中从231个猪场中32个阳性养殖场的病料中检出37份阳性样品,猪场阳性率为13.9%,样品阳性率为4.62%,并首次从种公猪精液中检出GETV。对该病毒Cap和NSP3基因扩增产物的进行序列分析,发现目前中国猪群中的GETV与日本近年猪源、马源及蚊源毒株亲缘关系最近,其次中国近年蚊源和韩国猪源毒株;遗传进化分析显示49个已知序列的GETV可分为3个群或谱系,其中75.5%的毒株属于2000年以后报道的Ⅲ群,具有明显的地域和年代特征且未发现物种特征。从样品中分离出两株GETV HNNY-1和HNJZ-S2,其全基因组均为11 689bp,且与Cap和NSP3基因序列分析结果基本一致,均与2012年以来的所有日本毒株亲缘关系最近。本研究首次揭示在我国4省份猪群中均有GETV存在且种公猪也可带毒,应引起人们重视。鉴于国内外目前均把该病毒看作是人兽共患病病原,因此有必要对其在中国猪群中的感染谱、传播途径、流行规律、致病性及防控措施等进行深人研究,为实时了解其在人畜间的感染和流行情况、制定有效防控措施提供科学依据。

In order to understand the emergence of the porcine Getah virus（GETV）in pig herds in China,801 tissue specimens from clinical disorder pigs from 231 herds in Shaanxi,Hebei,Henan and Anhui provinces,were tested by RT-PCR for amplifying Cap and NSP3 genes of GETV,followed by isolation and identification of the isolates.PCR products of Cap,NSP3 and full length genome of the isolates were sequenced and then analyzed together with those of the reference strains.The results showed that 37 out of801 samples（4.62%）from 32 of 231 farms（13.9%）in the four provinces were positive for the Cap and NSP3 genes of GETV,and two isolates were identified as GETV and named HNNY-1 and HNJZ-S2,respectively.The genome of the isolates HNNY-1 and HNJZ-S2 are 11,689 bp in size,which are similar to reference strains.More importantly,GETV was detected in boar semen for the first time,indicating that more attention should be paid to boars because of their potential risks of spreading the virus through their semen,which might affect pig herds and public health.Sequence alignment and phylogenetic analysis of Cap and NSP3 genes showed that the pig-borne isolates in China are more closed to,reported in recent years,horse-,swine-and mosquito-borne strains in Japan than those mosquito-borne in China and swineborne in Korea.Forty-nine known sequences of the GETV were divided into three gene clades in the phylogenetic trees,of which 75.5% belonged to clade I with obvious geographic and temporal characteristics,but without species characteristics.This study revealed for the first time that GETV has a wide range of transmission in the swine herds in 4 provinces in Chinese Mainland.Considering animal and human health,further study on the epidemiology and pathogenicity of the GETV.