实验小鼠感染鼠诺如病毒的检测

Detection of murine noroviruses from laboratory mice

目的了解实验小鼠鼠诺如病毒(murine norovirus,MNV)的携带情况及其基因特征。方法在广州某实验动物中心抽取两个种系的实验小鼠,采集其粪便标本,应用逆转录-聚合酶链式反应(RT-PCR)方法检测粪便标本的MNVORF2特异性基因(547bp,MNVnt5104～5650)。对阳性PCR产物进行测序并以测序结果构建基因进化树分析。结果共采集实验小鼠粪便标本20份,粪便来源的小鼠外表健康、活泼、进食正常,没有腹泻现象。MNV的阳性率为30.0%(6/20),阳性实验小鼠种类包括昆明小鼠(3/13)和NIH小鼠(3/7)。本研究检测的6个MNVs在进化树上独立一小分支,与参考株MNV2、3、4最为相近;核酸序列比较发现6个MNVs核酸序列的同源性最高,为98.3%～99.8%。结论该实验动物中心的小鼠存在较高的MNV携带状况,并可能在饲养设施内传播,有必要进一步探讨实验小鼠携带MNV的生物学意义。

Objective The purpose of the study is to investigate the prevalence of murine noroviruses （MNVs） in laboratory mice and analyze their genetic molecular characterization.Methods Fecal samples from two species of laboratory mice were tested for partial ORF2 region（547 bp,MNV nt 5104-5650）of MNV using RT-PCR method.Positive amplicons were sequenced.The sequences then were manipulated to constructe the phylogenetic tree.Results All of the mice sampled looked like healthy.Murine noroviruses were detected in 6 out of 20 samples（30%）,two species of mice screened were observed to carry MNVs,including Kunming mice （3/13） and NIH mice （3/7）.Phylogenetic analysis revealed that the six MNVs of this study were clustered into one group,which was mostly related with MNV 2,3,4.The pair wise sequences identities in ORF2 region within the six MNVs ranged from 98.3% to 99.8%.Conclusion This study showed that MNV infection occurred in the laboratory mice,and inter-species transmission of MNV with the same laboratory facilities is possible.It is necessary to study the biological significance of these findings.