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

BMC Veterinary Research

Case Report

Zuohua Li¹  Zheng Chen²  Shengwei Zhong²  Xinjie Qian²  Zhen Ding²  Hao Liu²  Xiangdong Wu²  Pei Ye²  Jinhua Zhang²  Huabin Cao³  Wenqi Liang³  Junrong Luo³  Guoliang Hu³  Ruiming Hu³  Nengshui Ding⁴ 

[1] College of Veterinary Medicine, Hunan Agricultural University, 410128, Changsha, China;Department of Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; No. 1101 Zhimin Avenue, Economic and Technological Development District, 330045, Nanchang, Jiangxi, China;Department of Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; No. 1101 Zhimin Avenue, Economic and Technological Development District, 330045, Nanchang, Jiangxi, China;Jiangxi Provincial Key Laboratory for Animal Health, Institute of Animal Population Health, Jiangxi Agricultural University, No. 1101 Zhimin Avenue, Economic and Technological Development District, 330045, Nanchang, Jiangxi, China;State Key Laboratory for Pig Genetic Improvement and Production Technology, Jiangxi Agricultural University, 330045, Nanchang, China;Key Laboratory of Swine Nutrition and Feed Science of Fujian Province, Aonong Group, 363000, Zhangzhou, China;

关键词: Porcine teschovirus;    Encephalitis;    Phylogeny;    Tertiary structure;   

DOI  :  10.1186/s12917-022-03549-1

 received in 2022-07-04, accepted in 2022-12-08,  发布年份 2022

来源: Springer

【 摘 要 】

BackgroundPorcine 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 presentationIn 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.ConclusionThese results indicate that HeNZ1 is a highly virulent PTV-2 strain, which capable of causing severe neurological symptoms and high mortality in piglets. Bioinformatic analysis suggest that HeNZ1 is genetically and antigenically different from other Chinese PTV-2 strains. Overall, current case expanded our understanding of PTV-2 clinical spectrum and revealed the emergence of a highly virulent PTV-2 strain with substantial genetic diversity and antigenic drift potential in VP1 and VP2.

【 授权许可】

CC BY   
© The Author(s) 2023

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