Virome Profiling of Bats from Myanmar by Metagenomic Analysis of Tissue Samples Reveals More Novel Mammalian Viruses

He, Biao; Li, Zuosheng; Yang, Fanli; Zheng, Junfeng; Feng, Ye; Guo, Huancheng; Li, Yingying; Wang, Yiyin; Su, Nan; Zhang, Fuqiang; Fan, Quanshui; Tu, Changchun

The genus Mamastrovirus, belonging to the family Astroviridae, is composed of 19 viral species based on the ORF2 gene [48] . In our study 35 and 22 contigs relating to genus Mamastrovirus were obtained from groups XM and WO respectively (Table 3) , but none from the other two groups. Testing of all bat lungs and guts by hemi-nested PCR using pan-bat astroviruses primers targeting a 422 nt fragment of ORF1b provided confirmation, resulting in 12 and 2 positive amplifications in guts of groups XM and WO respectively. The positive rate in Miniopterus fuliginosus was 4% (12/ 320). In group WO, only Rhinolophus ferrumequinum showed positive amplification in 2% (2/84) of samples, while all other bat species were negative. Of 15 amplicons, 8 (Accession numbers: JX863704-JX863711) were further sequenced and phylogenetically analyzed against representative astroviruses of all 19 species of Mamastroviruses based on the nt sequences. Results ( Figure 1 ) showed that the taxonomic tree of the 19 species of Mamastroviruses based on a partial ORF1b gene was the same as that based on ORF2. Bat astroviruses detected in this study, however, could be further grouped into two branches with 57-63% nt identity between them. Of these, BatAstv XMM137 amplified from M. fuliginosus in county Sedon shared the highest identity of 69% with Mamastrovirus 14 found in bats from Hong Kong [12] , and was likely a new Mamastrovirus species according to new ICTV criteria [48] . It was therefore tentatively classified as Mamastrovirus-related virus 1. The remaining 7 amplicons with 68-76% nt shared identity comprised a new group, and shared the highest nt identity (67-75%) with Mamastrovirus 18 found in Hong Kong bats [12] . These sequences constituted at least one new Mamastrovirus species according to new ICTV criteria, and were therefore classified as Mamastrovirus-related virus 2 [48] .