Wu Qingqing, Jiang Jianfeng, Li Qingxian, Xiao Chaoting, Chen Baoyu, Sun Mingkai, Xu Jiachao, Mi Shijiang, He Biao, Tu Changchun, Gong Wenjie
State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China.
State Key Laboratory of Pathogen and Biosecurity, Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China.
Transbound Emerg Dis. 2025 Jul 24;2025:3170440. doi: 10.1155/tbed/3170440. eCollection 2025.
Porcine astrovirus 3 (PAstV3) is an emerging virus associated with porcine polioencephalomyelitis outbreaks and is frequently detected in the feces of both healthy and diarrheal pigs. Despite its significance, the prevalence, genetic characteristics, and evolutionary features of PAstV3 in China remain poorly understood. Here, a retrospective study of PAstV3 infection was conducted using 634 tissue or fecal specimens collected from diseased pigs across 29 regions in China between 1990 and 2024. As a result, eight tissue samples and 32 fecal samples from seven regions tested positive for PAstV3, yielding an overall positive rate of 6.3% (40/634). Through a combination of metatranscriptomics (MTT) and RT-PCR, nearly complete genome sequences of 14 PAstV3 strains and full-length open reading frame (ORF) 2 sequences of another 13 PAstV3 strains were successfully obtained. Sequence analysis revealed that these strains exhibited a sequence identity of 59.8%-100% in the capsid protein. Phylogenetic analysis demonstrated that global PAstV3 strains could be classified into four genotypes: PAstV3a-d. The intergenotype strains showed nucleotide (nt) and amino acid sequence identities of 59.7%-69.8% and 59.5%-72.0%, respectively, in the ORF2 region. Notably, PAstV3b was identified as the predominant genotype in China. Sequence comparisons further confirmed the close genetic relationship between PAstV3 and neurotropic mammalian astroviruses, suggesting the potential interspecies transmission or a shared evolutionary origin. Phylodynamic analysis estimated that the most recent common ancestor (tMRCA) of PAstV3 emerged around the year 1660 and the effective population size of PAstV3 has been continuously expanding over time.
猪星状病毒3型（PAstV3）是一种新兴病毒，与猪脊髓灰质炎脑炎疫情有关，在健康猪和腹泻猪的粪便中均经常检测到。尽管其具有重要意义，但PAstV3在中国的流行情况、遗传特征和进化特征仍知之甚少。在此，利用1990年至2024年间从中国29个地区的患病猪采集的634份组织或粪便样本，对PAstV3感染进行了回顾性研究。结果，来自7个地区的8份组织样本和32份粪便样本PAstV3检测呈阳性，总体阳性率为6.3%（40/634）。通过宏转录组学（MTT）和逆转录聚合酶链反应（RT-PCR）相结合的方法，成功获得了14株PAstV3菌株的近乎完整的基因组序列以及另外13株PAstV3菌株的全长开放阅读框（ORF）2序列。序列分析显示，这些菌株的衣壳蛋白序列同一性为59.8%-100%。系统发育分析表明，全球PAstV3菌株可分为四个基因型：PAstV3a-d。基因型间菌株在ORF2区域的核苷酸（nt）和氨基酸序列同一性分别为59.7%-69.8%和59.5%-72.0%。值得注意的是，PAstV3b被确定为中国的主要基因型。序列比较进一步证实了PAstV3与嗜神经性哺乳动物星状病毒之间的密切遗传关系，表明可能存在种间传播或共同的进化起源。系统发育动力学分析估计，PAstV3的最近共同祖先（tMRCA）出现在1660年左右，并且PAstV3的有效种群大小随时间不断扩大。
