Abstract: Objective　To investigate the prevalence of murine norovirus (MNV) in commercial laboratory mice and the genomic characteristics of circulating strains.Methods　Reverse transcription polymerase chain reaction (RT-PCR) was employed to detect MNV infections in commercial Kunming mice from Beijing(10 samples), Shandong(10 samples), and Liaoning (15 samples). Positive samples were subjected to whole genome sequencing analysis.Results　The Kunming mice from different regions were infected with varying degrees of MNV. The whole genome sequencing and analysis of the positive sample MNV 2024BJ strain revealed a genome length of 7 382 nt, and the nucleotide homology with the representative MNV strains ranging from 88.9% to 89.9%. Structural analyses of the ORF1 cleavage site, glycosylation site, and non coding region indicated similarities between this strain and the representative strains of MNV genotype 1. Phylogenetic analysis demonstrated that this strain is closely related to domestic Guangzhou/K162/09/CHN and BJ10-2062 strains, and belongs to the same evolutionary branch.Conclusion　MNV infection is common in commercial Kunming mice, with certain  differences in nucleotide homology with reported strains at home and abroad, the potential risks caused by it should be further emphasized.

Key words: murine norovirus, complete genome, genetic evolution analysis

摘要： 目的　调查商品化实验小鼠中小鼠诺如病毒(MNV)携带情况及流行毒株的基因组特征。方法　采用反转 录-聚合酶链式反应(RT-PCR)方法对北京(10个样本)、山东(10个样本)及辽宁(15个样本)商品化昆明小鼠 MNV感染情况进行检测,并对阳性样本病毒株进行全基因组测序分析。结果　不同地区昆明小鼠均有不同程度 MNV感染。阳性样本中MNV 2024BJ株全基因组序列测定及分析显示,该毒株基因组全长为7 382 nt,与MNV代 表株核苷酸同源性为88.9%~89.9%。开放阅读框1裂解位点、糖基化位点及非编码区结构分析显示毒株与 MNV1亚型代表毒株相似。系统发生进化树分析结果表明,该毒株与国内Guangzhou/K162/09/CHN及BJ10-2062 毒株进化距离较近,同属一个进化分支。结论　商品化昆明小鼠中MNV感染较为普遍,且与国内外报道毒株同源 性存在一定差异,其引起的潜在危害应进一步重视。

关键词: 小鼠诺如病毒, 全基因组, 遗传进化分析