2022年江苏省4种猪腹泻病毒分子流行病学调查

Molecular epidemiological investigation of four swine diarrhea viruses in Jiangsu Province in 2022

为了解江苏省猪流行性腹泻病毒(PEDV)、猪传染性胃肠炎病毒(TGEV)、猪δ冠状病毒(PDCoV)、猪轮状病毒(PoRV)流行毒株的遗传变异趋势,采集了2022年江苏省不同猪场的病猪腹泻病料36份,使用RT-PCR方法分别检测PEDV、TGEV、PDCoV和PoRV感染情况,并对部分检测结果为阳性的PEDV、TGEV、PDCoV进行S基因扩增、测序和分析,对PoRV进行VP4、VP7基因扩增、测序和分析,共获得8个PESV S基因,1个TGEV S基因,1个PDCoV S基因,9个PoRV VP4及VP7基因序列。基于PEDV S基因的序列分析结果表明,2022年江苏PEDV流行毒株与我国2010年以来流行的GⅡ-b亚群变异株的序列同源性为97.0%~99.7%,属于同一亚群,而与CV777、SD-M等早期毒株亲缘关系较远;江苏PEDV流行毒株S1蛋白区域存在氨基酸的突变、插入及缺失,不同流行毒株之间存在一定的差异。基于TGEV S基因的序列分析结果表明,江苏TGEV流行毒株与中国毒株WH-1同源性最高,为99.9%;其S基因仅发生了3个氨基酸突变。基于PDCoV S基因的序列分析结果表明,江苏PDCoV流行毒株与CHN/HG/2017株的同源性最高,为98.2%,与来自中国、越南、老挝、泰国等东南亚国家的毒株亲缘关系较近,属于同一群;江苏PDCoV流行毒株的S1蛋白区域发生6个氨基酸的突变。基于PoRV VP4及VP7基因的序列分析结果表明,江苏PoRV流行毒株属于A群轮状病毒,具有G3[P13]型、G3[P23]型、G4[P13]型、G4[P23]型、G9[P13]型、G9[P23]和G11[P13]型7个不同的基因组合型。本研究结果为掌握江苏地区PEDV、TGEV、PDCoV、PoRV的流行情况、遗传进化趋势及其防控提供了理论依据。

In order to understand the trend of genetic variation of porcine epidemic diarrhea virus(PEDV),transmissible gastroenteritis vi⁃rus(TGEV),porcine deltacoronavirus(PDCoV)and porcine rotavirus(PoRV)epidemic strains in Jiangsu Province,36 diarrhea samples from diseased pigs on different pig farms in the area were collected and detected by RT-PCR for PEDV,TGEV,PDCoV and PoRV.Then,S gene amplification,sequencing,and analysis were performed on some PEDV,TGEV,and PDCoV with positive detection results.VP4 and VP7 gene amplification,sequencing,and analysis were performed on PoRV.A total of 8 PESV S genes,1 TGEV S gene,1 PDCoV S gene,and 9 PoRV VP4 and VP7 gene sequences were obtained.The results of the sequence analysis based on PEDV S gene showed that the se⁃quence homology between the Jiangsu PEDV epidemic strain and the GⅡ-b variant strain that has been prevalent in China since 2010 was 97%-99.7%,belonging to the same subgroup,but genetically far from CV777,SD-M and other early strains.There were mutations,inser⁃tions and deletions of amino acids in S1 protein of the Jiangsu PEDV epidemic strains.There were also certain differences among different ep⁃idemic strains.The sequence analysis based on TGEV S gene showed that the Jiangsu TGEV epidemic strain possessed the highest homology with the Chinese strain WH-1(99.9%).Only three amino acid mutations occurred in its S gene.Based on the sequence analysis of the PD⁃CoV S gene,the PDCoV epidemic strain in Jiangsu had the highest homology with the CHN/HG/2017 strain,which was 98.2%.It was close to the strains from China,Vietnam,Laos,Thailand and other Southeast Asian countries and they belonged to the same group.Six amino acid mutations occurred in the S1 protein region of the Jiangsu PDCoV epidemic strain.Based on the sequence analysis of the PoRV VP4 and VP7 genes,the PoRV epidemic strain in Jiangsu belonged to the group A rotavirus,with seven different gene combinations:G3[P13],G3[P23],G4[P13],G4[P23],G9[P13],G9[P23],and G11[P13].The results of this study provided a theoretical basis for mas⁃tering the epidemic situation,genetic evolution trend and prevention and control of PEDV,TGEV,PDCoV and PoRV in Jiangsu Province.