Shi Kaichuang, Hu Xin, Long Feng, Shi Yuwen, Pan Yi, Feng Shuping, Li Zongqiang, Yin Yanwen
School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, China.
College of Animal Science and Technology, Guangxi University, Nanning, China.
Front Microbiol. 2024 Oct 9;15:1474552. doi: 10.3389/fmicb.2024.1474552. eCollection 2024.
Porcine hemagglutinating encephalomyelitis virus (PHEV) is the only known porcine neurotropic coronavirus, which is prevalent worldwide at present. It is of great significance to understand the genetic and evolutionary characteristics of PHEV in order to perform effective measures for prevention and control of this disease. In this study, a total of 6,986 tissue samples and nasopharyngeal swabs were collected from different regions of Guangxi province in southern China during 2021-2024, and were tested for PHEV using a quadruplex RT-qPCR. The positivity rate of PHEV was 2.81% (196/6,986), of which tissue samples and nasopharyngeal swabs had 2.05% (87/4,246) and 3.98% (109/2,740) positivity rates, respectively. Fifty PHEV positive samples were selected for PCR amplification and gene sequencing. Sequence analysis revealed that the nucleotide homology and amino acid similarities of S, M, and N genes were 94.3%-99.3% and 92.3%-99.2%, 95.0%-99.7% and 94.7%-100.0%, 94.0%-99.5% and 93.5%-99.3%, respectively, indicating M and N genes were more conservative than S gene. Phylogenetic trees based on these three genes revealed that PHEV strains from different countries could be divided into two groups G1 and G2, and the PHEV strains from Guangxi province obtained in this study distributed in subgroups G1c and G2b. Bayesian analysis revealed that the population size of PHEV has been in a relatively stable state since its discovery until it expanded sharply around 2015, and still on the slow rise thereafter. S gene sequences analysis indicated that PHEV strains existed variation of mutation, and recombination. The results indicated that the prevalent PHEV strains in Guangxi province had complex evolutionary trajectories and high genetic diversity. To the best of our knowledge, this is the first report on the genetic and evolutionary characteristics of PHEV in southern China.
猪血凝性脑脊髓炎病毒（PHEV）是目前已知的唯一一种嗜神经性猪冠状病毒，在全球范围内广泛流行。了解PHEV的遗传和进化特征对于采取有效的疾病防控措施具有重要意义。本研究于2021年至2024年期间，从中国南方广西不同地区共采集了6986份组织样本和鼻咽拭子，采用四重RT-qPCR法检测PHEV。PHEV的阳性率为2.81%（196/6986），其中组织样本和鼻咽拭子的阳性率分别为2.05%（87/4246）和3.98%（109/2740）。选取50份PHEV阳性样本进行PCR扩增和基因测序。序列分析显示，S、M和N基因的核苷酸同源性和氨基酸相似性分别为94.3%-99.3%和92.3%-99.2%、95.0%-99.7%和94.7%-100.0%、94.0%-99.5%和93.5%-99.3%，表明M和N基因比S基因更保守。基于这三个基因构建的系统发育树显示，来自不同国家的PHEV毒株可分为G1和G2两组，本研究获得的广西PHEV毒株分布在G1c和G2b亚组中。贝叶斯分析显示，PHEV的种群大小自发现以来一直处于相对稳定状态，直到2015年左右急剧扩大，此后仍在缓慢上升。S基因序列分析表明，PHEV毒株存在突变和重组变异。结果表明，广西流行的PHEV毒株具有复杂的进化轨迹和较高的遗传多样性。据我们所知，这是中国南方关于PHEV遗传和进化特征的首次报道。
