与猪同群饲养山羊暴发伪狂犬病的确诊及山羊源伪狂犬病病毒JC株的分离鉴定

Diagnosis of pseudorabies brokenout in goats reared with fattening pigs and isolation and identification of pseudorabies virus JC strain derived from goats

2015年11月云南省江川县某养殖户家中与育肥猪同群饲养的136只山羊相继暴发以发热、食欲减退、烦躁不安、全身剧烈瘙痒及高死亡率为特征的疫情。为及时确诊病因,我们采集病死山羊内脏及大脑组织进行山羊关节炎/脑炎、狂犬病及伪狂犬病病毒核酸检测,同时进行病毒分离培养、鉴定,并采集育肥猪血清样品进行伪狂犬病病毒gB及gE抗体检测。结果显示,从病死山羊大脑组织中扩增出约810bp大小的伪狂犬病病毒gE(US8)基因目的条带,并分离获得1株山羊源伪狂犬病病毒流行毒株,命名为JC株,毒株滴度为TCID50=10-7.375/100μL,其gE基因序列在NCBI GenBank中的比对结果显示,其与2014年的Qihe547(KU056477)株、2013年的HLJ8(KT824771)株、2012年的HNX(KM189912)及HeN1(KP098534)株的gE基因核苷酸序列同源性均达99%。JC株与云南伪狂犬病病毒猪源毒株FY、LL、XD及XSBN株的gE基因序列比对结果显示,其仅在290位置处有1个碱基C的插入,在1469~1471位置处有3个碱基GAC的缺失。JC株与云南猪源毒株30938、LL、XD及XSBN株的TK、gC基因序列比对结果显示,其TK基因序列完全相同,仅在gC基因序列58位置处有1个碱基的变异(G→A),其余序列完全相同。将JC毒株接种家兔、昆明小白鼠及经伪狂犬病病毒gE、gB抗体呈阴性的健康山羊后,均复制出典型的伪狂犬病病例。采集的16份猪血清样品伪狂犬病病毒gB及gE抗体检测结果均为阳性。根据流行病学、病原学研究及血清学检测结果分析,确诊引起此次山羊疫情的病因为山羊与猪同群饲养后,受伪狂犬病病毒隐性带毒猪传染所致。

In November 2015,agroup of 136goats raised with fattening pigs in a breeding farm in Jiangchuan,Yunnan,successively developed a kind of disease characterized by fever,anorexia,irritability,severe itching and high mortality.In order to diagnose the cause of the disease in time,the visceral and brain tissue of the dead goat were collected for virus nucleic acid detection of goat arthritis/encephalitis,rabies and pseudorabies.At the same time,the virus isolation and identificationwas carried out.The serum samples of fattening pigs were also collected to detect gB and gE antibody of pseudorabies.The target band of the pseudorabies gE(US8)gene about 810bp size was amplified from the brain tissue of the sick and dead goat.A pseudorabies virus strain was isolated and named JC strain and the virus titer(TCID50)was 10-7.375/100μL.The sequence alignment of gE gene from JC strain showed that the nucleotide sequence homology with Qihe547gene(KU056477)strain in 2014,HLJ8(KT824771)strain in 2013,HNX(KM189912)and HeN1(KP098534)strain in 2012was all 99%.The sequence alignment of gEgene between JC strain and FY,LL,XD and XSBN strain derived from pig in Yunnan showed that the insertion of 1base C was only at 290position,and there was 3base GAC deletion at 1469-1471position.The sequence comparison of TK and gCgenes between JC strain and 30938,LL,XD and XSBN strains derived from pig in Yunnan showed that their TK gene sequences were exactly the same and they had only 1base variation(G to A)at the 58position of gCgene sequence,and the rest sequences were identical.After inoculating JC strain into rabbits,Kunming mice and healthy goats with no antibody against to pseudorabies,the typical pseudorabies cases were reproduced.The results of the detection of gB and gE antibody of 16porcine serum samples were all positive.According to epidemiological analysis,etiological study and serological test results,the goat epidemic disease was pseudorabies which was caused by group feeding with fattening pigs.