关键词: <, p>, 诺如病毒, 小鼠, 病毒分离, 鉴定<, /p>

Abstract: Abstract: Objective The purpose of the study is to investigate the prevalence of murine norovirus ( MNV) in Jiangsu province and analyze their genetic molecular characterization． Method Experimental mice were extracted from three experimental animal centers in Jiangsu area． Ｒectal samples from the experimental mice were tested for partial OＲF2 region ( 547bp，MNV nt 5104-5650) of MNV using ＲT-PCＲ method． We used mouse macrophage cell line ＲAW264. 7 to isolate MNV from the rectal contents of the infected mice． Fragments of VP1genes from MNV isolates were amplified by ＲT-PCＲ and then ligated to pEASY-Blunt Simple CloningVector and cloned to Trans1-T1 chemically competent cells． By kanamycin lysogeny broth plate selection， the positive clones were sequenced and analyzed． Based on the VP1 gene， thephylogenetic analysis tree was created． Ｒesult 4 positive MNV isolates were obtained from 30 mice rectal samples，including ICＲ mice( 2 /8) ，BALB /c mice( 1 /12) and C57BL /6Jmice ( 1 /10) ，infection rate was 13%． On infection，the ＲAW264. 7 cell line inoculated with two ICＲ mice sample showed obvious cytopathic effects ( CPE) after three genetations，as infected cells became rounded and shrunken，with ultimate disintegration of the cell sheet． The ＲAW264. 7 cell line inoculated with BALB /c and C57BL /6J mice samples did not exhibit CPE． Used VP1specific primers，we found the specific bands appeared in the CPE cells sample of two ICＲ mice by ＲT-PCＲ method． The sequencing results showed both of the complete VP1 gene of two MNV strains was 1626bp，which was the same length as that of the reference strain S7-P2 ( GenBank accession number: AB435514) VP1 gene． Phylogenetic analysis showed that the two MNVs of this study were clustered into one group which was mostly related withBJ10-2062 and CＲ4． Conclusion The MNV infection rate was 13. 3% ( 4 /30) in the experimental mice of Jiangsu area． May be MNV transmitted within the breeding facilities． We need to further explore the biological significance of the experimental mice carrying MNV．

Key words: <p>mouse norovirus( MNV) , mice, virus isolation, identification</p>