肠道病毒G(EV-G)在世界范围内的猪群中流行,共确认了20种基因型(G1至G20)。最近,已分离或检测到携带猪圆环病毒木瓜蛋白酶样半胱氨酸蛋白酶(PLCP)基因的重组EV-Gs,而其致病性却知之甚少。在这项研究中,EV-G17-PLCP菌株,\'EV-G/YN23/2022\',从腹泻猪的粪便中分离出来,病毒在许多细胞系中强劲复制。与G17菌株\'IShi-Ya4\'(LC549655)有关,该分离株显示出最高的完整基因组核苷酸(87.5%)和多蛋白氨基酸(96.6%)同一性,在EV-G/YN23/2022基因组的708和3383位检测到可能的重组事件。EV-G/YN23/2022对仔猪是非致命性的,但轻度腹泻,短暂的发热,典型的皮肤损伤,观察到体重增加减速。病毒在多个器官中有效复制,病理病变主要位于小肠。所有受攻击的仔猪在接种后(dpi)6至9天显示EV-G/YN23/2022的血清转化,中和抗体在15dpi达到峰值。IL-6、IL-18、IFN-α、IFN-β,在病毒感染期间,外周血单个核细胞(PBMC)中的ISG-15显著上调。本文是EV-G17-PLCP株在中国的分离和致病性评价的第一份文献。该结果可能会促进我们对EV-G-PLCP的演变特征和发病机制的理解。
Enterovirus G (EV-G) is prevalent in pig populations worldwide, and a total of 20 genotypes (G1 to G20) have been confirmed. Recently, recombinant EV-Gs carrying the papain-like cysteine protease (PLCP) gene of porcine torovirus have been isolated or detected, while their pathogenicity is poorly understood. In this study, an EV-G17-PLCP strain, \'EV-G/YN23/2022\', was isolated from the feces of pigs with diarrhea, and the virus replicated robustly in numerous cell lines. The isolate showed the highest complete genome nucleotide (87.5%) and polyprotein amino acid (96.6%) identity in relation to the G17 strain \'IShi-Ya4\' (LC549655), and a possible recombination event was detected at the 708 and 3383 positions in the EV-G/YN23/2022 genome. EV-G/YN23/2022 was nonlethal to piglets, but mild diarrhea, transient fever, typical skin lesions, and weight gain deceleration were observed. The virus replicated efficiently in multiple organs, and the pathological lesions were mainly located in the small intestine. All the challenged piglets showed seroconversion for EV-G/YN23/2022 at 6 to 9 days post-inoculation (dpi), and the neutralization antibody peaked at 15 dpi. The mRNA expression levels of IL-6, IL-18, IFN-α, IFN-β, and ISG-15 in the peripheral blood mononuclear cells (PBMCs) were significantly up-regulated during viral infection. This is the first documentation of the isolation and pathogenicity evaluation of the EV-G17-PLCP strain in China. The results may advance our understanding of the evolution characteristics and pathogenesis of EV-G-PLCP.