内蒙古包头地区猪戊型肝炎病毒的流行特征及其ORF2分子特征分析  

Epidemiological characteristics and molecular features analysis of porcine HEV in Baotou,Inner Mongolia

作　　者：王树鹏 方苓[2] 任可[1] 刘锦龙 张宇[1,3] 白慧敏 WANG Shu-peng;FANG Ling;REN Ke;LIU Jin-long;ZHANG Yu;BAI Hui-min(Inner Mongolia University of Science&Technology Baotou Medical College Basic Medicine and Forensic Medicine,Baotou 014040,China;Guangdong Provincial Center for Disease Control and Prevention Pathogenic Microbiology Laboratory,Guangzhou 511430,China;Kundulun District Center for Disease Control and Prevention,Baotou 014030,China)

机构地区：[1]内蒙古科技大学包头医学院基础医学与法医学院,内蒙古包头014040 [2]广东省疾病预防控制中心病原微生物检验所,广东广州511430 [3]内蒙古包头市昆都仑区疾病预防控制中心,内蒙古包头014030

出　　处：《中国预防兽医学报》2024年第12期1293-1297,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：内蒙古自然科学基金(2021MS08059);2022年度内蒙古自治区留学人员创新创业启动支持项目(HEV嵌合疫苗设计及其ORF3疫苗免疫协同作用的研究)。

摘　　要：为调查内蒙古包头地区猪戊型肝炎病毒(HEV)的感染情况,并分析其基因特征,本研究从内蒙古包头周边地区共收集猪血清样品186份经ELISA方法检测其HEV IgG抗体;收集猪粪便样品96份提取总RNA,经套式PCR检测HEV ORF2基因,测序后采用MEGA11.0构建进化树。结果显示,猪血清样品中HEV IgG抗体的总阳性率高达78.49%(146/186);猪粪便样品检测到2份HEV阳性样品,经克隆ORF2部分基因并测序后推导分析氨基酸序列,结果显示2份HEV阳性样品所属HEV基因型为Genotype 4,氨基酸序列分析首次检测到HEV ORF2氨基酸突变位点E^(276)G;HEV ORF2编码病毒衣壳蛋白,包含S(Shell)、M(Middle)和P(Protruding)3个结构域,ColabFold预测结果显示,S结构域的E^(276)G突变可能导致HEV ORF2与受体结合的P结构域的折叠发生约90°偏转。上述结果表明内蒙古包头地区猪群中存在HEV的流行,且感染情况很普遍、感染率较高,主要流行株为HEV Genotype 4,小型饲养场中感染率较饲养散户的感染率更高;2份粪便阳性样品均来自同一养殖场可证明该养殖场正处于HEV感染期;新发现的E^(276)G突变可使HEV ORF2 P结构域折叠发生改变,是否导致HEV抗原性改变仍需进一步探究。本研究揭示了内蒙古包头地区圈养猪群中HEV的感染特征,并首次发现其ORF2 E^(276)G突变对其受体结合区(P区)结构存在潜在影响,为HEV的人兽共患防控和机制研究提供新的依据。In order to investigate the epidemiological characteristics feature of porcine hepatitis E virus(HEV)in Baotou,Inner Mongolia,a total of 186 porcine serum samples and 96 porcine faecal samples were collected from surrounding areas in the present study;both anti-HEV-IgG antibody and HEV ORF2 gene were detected,respectively.A phylogenetic tree was constructed based on the amino acid sequences obtained.The results showed that the overall positive rate of anti-HEV-IgG antibodies in pig serum samples was up to 78.49%;two of 96 feacal samples were positive for HEV RNA,and the obtained ORF2 nucleotieds were cloned,sequenced and a phylogenetic tree analysis was performed.As the results showed that the resulting two sequences were determined as genotype 4 of HEV,and the new amino acid mutation site E^(276)G of HEV ORF2 was discovered for the first time,which located in ORF2 S domain.The results predicted by ColabFold showed that the E^(276)G mutation in the S domain might lead to 90°deviation in the folding of the P domain responsible for receptor binding in HEV ORF2.In this study,we showed that HEV was prevalent in pig herds in Baotou,Inner Mongolia,and the HEV infection was a very common situation,the rate of infection rate was very high.The main prevalent strain is HEV genotype 4,and the infection rate was higher in small-scale farms than that in individual farms;two positive faecal samples came from the same farm demonstrating that this farm was in the acute transmission stage of HEV.New mutation site E^(276)G discovered by us can change the folding of ORF2 P domain,however,further investigation will be needed to determine whether it leads to changes in the antigenicity of HEV.In short,this study revealed the infection characteristics of HEV in pig herds in Baotou,Inner Mongolia and discovered the potential impact of nucleocapsid protein ORF2 E^(276)G mutation on the structure of its receptor binding region(P region),providing new evidence for the prevention and mechanism research.

关 键 词：戊型肝炎病毒 感染与流行 蛋白质结构预测 

分 类 号：S852.65[农业科学—基础兽医学]