Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Coinnovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Vet Microbiol. 2020 Jan;240:108511. doi: 10.1016/j.vetmic.2019.108511. Epub 2019 Nov 15.
Since late 2010, highly virulent PEDV G2-genotype strains have emerged globally extracting heavy losses on the pork industries of numerous countries. We investigated the characteristics of a field strain of PEDV (PEDV strain SH) isolated from a piglet with severe diarrhea on a farm in Shanghai China. Whole genome sequencing and analysis revealed that the SH strain belonged to subtype G2b and has a unique 12-aa deletion (aa 399-410) including the antigenic epitope NEP-1C9 (aa 398-406) of the N protein. PEDV SH strain is highly pathogenic to challenged newborn piglets, resulting in 100 % morbidity and mortality. Pathological examination revealed significant villus atrophy in the jejuna of infected piglets. Mice inoculated with inactivated PEDV SH produced antibodies against the N protein, but no antibodies against the deletions. These results illustrated that deletion of the NEP-1C9 epitope had no effect on the immunogenicity or pathogenicity of PEDV, providing evidence of the necessity to monitor the genetic diversity of the virus. Our study also contributes to development of candidate for vaccines and diagnostics that could differentiate pigs seropositive due to vaccination by conventional strains from wild virus infection.
自 2010 年底以来，高毒力的 PEDV G2 基因型毒株在全球范围内出现，给许多国家的养猪业造成了巨大损失。我们研究了一株从中国上海某农场出现严重腹泻仔猪中分离到的 PEDV 田间分离株（PEDV 株 SH）的特征。全基因组测序和分析表明，SH 株属于 G2b 亚群，具有独特的 12 个氨基酸缺失（aa399-410），包括 N 蛋白的抗原表位 NEP-1C9（aa398-406）。PEDV SH 株对新生仔猪具有高度致病性，导致 100%的发病率和死亡率。病理检查显示感染仔猪空肠绒毛明显萎缩。用灭活的 PEDV SH 接种的小鼠产生了针对 N 蛋白的抗体，但对缺失没有产生抗体。这些结果表明，NEP-1C9 表位的缺失对 PEDV 的免疫原性或致病性没有影响，这为监测病毒的遗传多样性提供了证据。我们的研究也为疫苗和诊断试剂的开发提供了依据，这些试剂可以区分由于常规毒株接种而产生血清阳性的猪和野生病毒感染。
