驴流产样品中马疱疹病毒2型的鉴定与遗传进化分析

Identification and analysis of equid herpesvirus 2 in samples from aborted donkey

为了解马疱疹病毒2型(EHV-2)在驴群中的流行情况,本研究采集新疆伊犁察布查尔锡伯自治县某驴场流产母驴血清104份,利用PCR方法检测EHV-2的携带情况。结果显示,4份驴血清携带EHV-2,阳性率为2.9%,表明该驴场流产母驴携带EHV-2。遗传进化分析显示,本研究鉴定的EHV-2 Chabuchar16、Chabuchar31和Chabuchar34与波兰EHV-2 PL_EHV2_44、PL_EHV2_39_Ⅷ株处于同一进化分支,EHV-2 Chabuchar35与波兰EHV-2处于另一进化分支,表明有2种EHV-2基因型感染驴,且均与致伊犁马流产的EHV-2 XJ-YLZS28和XJ-YLZS28株亲缘关系较远。同源性分析显示:EHV-2 Chabuchar16、Chabuchar31和Chabuchar34与波兰马源EHV-2 PL_EHV2_39_Ⅷ株g B基因序列同源性为98%~99.6%,氨基酸序列同源性为97.5%~99.6%;EHV-2 Chabuchar35与波兰马源EHV-2PL_EHV2_3_I株g B基因序列同源性为99.7%,氨基酸序列同源性为100%,表明驴源EHV-2可能为外来病毒,且来源于马。另外,本研究鉴定的4株EHV-2 g B氨基酸序列在D^(165)N、P^(183)T、R^(196)K、S^(202)V和K^(217)R等位点发生了突变。本研究首次在流产驴血清中检测到EHV-2,并对其g B基因进行了遗传进化分析,为驴源EHV-2的流行病学研究提供了基础数据。

In order to understand the prevalence of equid herpesvirus 2(EHV-2)in donkeys,104 serum samples were collected from donkeys having abortions on a farm in Chabuchar County,Yili,Xinjiang.PCR results showed that the EHV-2 gB gene was detected in four samples,with a positive rate of 2.9%(4/104),indicating that the aborted donkeys carry EHV-2.Phylogenetic tree construction based on the gB gene showed that EHV-2 Chabuchar16,Chabuchar31,and Chabuchar34 related to the lineage of EHV-2 reference strains PL_EHV2_44 and PL_EHV2_39_Ⅷin Poland.In contrast,EHV-2 Chabuchar35 was clustered with the EHV-2 reference strain PL_EHV2_3_I from Poland.These results revealed that there were two different clusters of EHV-2 infecting donkeys.Sequence analysis of the gB gene revealed that the identity of nucleotide(nt)and amino acid(aa)between Chabuchar16,Chabuchar31,Chabuchar34,and EHV-2 PL_EHV2_39_Ⅷwere 98.3%-99.9%,and 97.1%-100%respectively.In contrast,the EHV-2 Chabuchar35 shared a similarity of 99.7%in nt and 100%in aa with Poland EHV-2 PL_EHV2_3_I.The results indicated that the donkey-derived EHV-2 in this study might be an exotic virus originating from horses.In addition,the amino acid sequences of the four donkey-origin EHV-2 gB had mutations of D^(165)N,P^(183)T,R^(196)K,S^(202)V,and K^(217)R.In the current study,the EHV-2 was first reported in the serum samples of the aborted donkeys and first took genetic evolution analysis of their gB gene.These findings provide fundamental data for the epidemiological study of donkey-origin EHV-2.