Identification of a novel porcine Teschovirus 2 strain as causative agent of encephalomyelitis in suckling piglets with high mortality in China

作者：Wenqi Liang, Xiangdong Wu, Zhen Ding, Shengwei Zhong, Xinjie Qian, Pei Ye, Hao Liu, Zheng Chen, Jinhua Zhang, Huabin Cao, Guoliang Hu, Junrong Luo, Zuohua Li, Nengshui Ding, Ruiming Hu · 发表于：BMC Veterinary Research · 年份：2023 · DOI：10.1186/s12917-022-03549-1 · 被引用次数：13 · 研究领域：Viral Infections and Immunology Research、Cytomegalovirus and herpesvirus research、Animal Virus Infections Studies

BACKGROUND: Porcine Teschovirus (PTV), also named Teschovirus A, is prevalent in pig populations, mainly causing neurological symptoms, diarrhea, pneumonia, and reproductive failure, however the morbidity and mortality are usually low in pig farms. CASE PRESENTATION: In this study, we reported a PTV outbreak investigation in one large-scale pig farm in China with severe symptoms including diarrhea, lethargy, locomotor ataxia, nystagmus, paralysis of the hind limbs, and coma in piglets. More importantly, the mortality reached 38% in suckling pigs, which is remarkably high in PTV history. A novel PTV strain, named HeNZ1, was isolated from cerebral samples of one suckling pig and the genome sequence was obtained by NGS sequencing. Phylogenetic and evolutionary divergence analyses revealed that HeNZ1 belongs to PTV genotype 2. Surprisingly, the VP1 coding region of HeNZ1 shares the highest sequence similarity with European PTV-2 strains, instead of China domestic PTV-2 strains, implying it may not derive from China local PTV-2 strains. Multiple sequence alignment and B cell epitope prediction of PTV VP1 and VP2 protein revealed 10 B cell epitopes, 5 mutant clusters and 36 unique mutation sites, of which 19 unique mutation sites are located in B cell epitopes and exposed on the surface of VP1 or VP2, implying significant antigenic drift potential of HeNZ1. CONCLUSION: These results indicate that HeNZ1 is a highly virulent PTV-2 strain, which capable of causing severe neurological ...