Abstract

Viruses belonging to the genus Norovirus (NoV) of the family Caliciviridae are the major cause of acute viral gastroenteritis worldwide. NoVs are classified into 10 genogroups (GI-GX), and those belonging to the genogroup GV are able to infect several species of rodents. To evaluate the circulation of MNV among mice housed in an Italian facility, sampling was performed over two separate periods, in 2011, and 3 years later in 2014. During the two samplings, 75 fecal samples were collected from healthy mice housed in the animal facility and subjected to RT-PCR for viral detection. After the analysis, 41/75 animals (54.6%) resulted positive for the presence of MNV in feces. Nucleotide sequencing revealed the presence of two MNV variants co-circulating in both 2011 and 2014. One MNV strain was isolated on RAW264.7 cell line, and subjected to full genome sequencing. Our study showed that the murine noroviruses are widespread in the investigated animal facility, despite guidelines for animal care and maintenance. Full genome sequence analysis of the MNV strain described in this study showed a correlation with other strains circulating in Europe. Understanding the molecular epidemiology of this virus should give insight into its natural history and evolution in mice.

 抽象的

杯状病毒科诺如病毒（NoV）属的病毒是全世界急性病毒性胃肠炎的主要原因。 NoV 分为 10 个基因组 (GI-GX)，属于 GV 基因组的 NoV 能够感染多种啮齿动物。为了评估意大利设施中饲养的小鼠中 MNV 的循环情况，在 2011 年和 3 年后的 2014 年两个不同时期进行了采样。在这两次采样期间，从动物设施中饲养的健康小鼠中收集了 75 份粪便样本并进行RT-PCR进行病毒检测。分析后，41/75 只动物 (54.6%) 的粪便中 MNV 呈阳性。核苷酸测序揭示了 2011 年和 2014 年共循环的两种 MNV 变种的存在。在 RAW264.7 细胞系上分离出一种 MNV 毒株，并进行了全基因组测序。我们的研究表明，尽管有动物护理和维护指南，但鼠诺如病毒在所调查的动物设施中广泛存在。本研究中描述的 MNV 毒株的全基因组序列分析显示与欧洲流行的其他毒株存在相关性。了解这种病毒的分子流行病学应该有助于深入了解其在小鼠体内的自然史和进化。