Detection and genome characterization of four novel bat hepadnaviruses and a hepevirus in China

Bo Wang,Claus-Thomas Bock,Yun-Zhi Zhang,Zheng-Li Shi,Wen Li,Yan Zhu,Xing-Yi Ge,Xing-Lou Yang,Li-Biao Zhang

doi:10.1186/s12985-017-0706-8

Abstract

BackgroundIn recent years, novel hepadnaviruses, hepeviruses, hepatoviruses, and hepaciviruses have been discovered in various species of bat around the world, indicating that bats may act as natural reservoirs for these hepatitis viruses. In order to further assess the distribution of hepatitis viruses in bat populations in China, we tested the presence of these hepatitis viruses in our archived bat liver samples that originated from several bat species and various geographical regions in China.MethodsA total of 78 bat liver samples (involving two families, five genera, and 17 species of bat) were examined using nested or heminested reverse transcription PCR (RT-PCR) with degenerate primers. Full-length genomic sequences of two virus strains were sequenced followed by phylogenetic analyses.ResultsFour samples were positive for hepadnavirus, only one was positive for hepevirus, and none of the samples were positive for hepatovirus or hepacivirus. The hepadnaviruses were discovered in the horseshoe bats, Rhinolophus sinicus and Rhinolophus affinis, and the hepevirus was found in the whiskered bat Myotis davidii. The full-length genomic sequences were determined for one of the two hepadnaviruses identified in R. sinicus (designated BtHBVRs3364) and the hepevirus (designated BtHEVMd2350). A sequence identity analysis indicated that BtHBVRs3364 had the highest degree of identity with a previously reported hepadnavirus from the roundleaf bat, Hipposideros pomona, from China, and BtHEVMd2350 had the highest degree of identity with a hepevirus found in the serotine bat, Eptesicus serotinus, from Germany, but it exhibited high levels of divergence at both the nucleotide and the amino acid levels.ConclusionsThis is the first study to report that the Chinese horseshoe bat and the Chinese whiskered bat have been found to carry novel hepadnaviruses and a novel hepevirus, respectively. The discovery of BtHBVRs3364 further supports the significance of host switches evolution while opposing the co-evolutionary theory associated with hepadnaviruses. According to the latest criterion of the International Committee on Taxonomy of Viruses (ICTV), we hypothesize that BtHEVMd2350 represents an independent genotype within the species Orthohepevirus D of the family Hepeviridae.

Highlights

In recent years, novel hepadnaviruses, hepeviruses, hepatoviruses, and hepaciviruses have been discovered in various species of bat around the world, indicating that bats may act as natural reservoirs for these hepatitis viruses
We report the discovery of four novel hepadnaviruses and a hepevirus in our archived bat liver samples that had been collected from several bat species and various geographical regions in China
The nucleotide sequences of the four novel hepadnaviruses and the hepevirus described in this study are available from GenBank under the accession numbers KX513949–KX513953

Summary

Introduction

Novel hepadnaviruses, hepeviruses, hepatoviruses, and hepaciviruses have been discovered in various species of bat around the world, indicating that bats may act as natural reservoirs for these hepatitis viruses. Bats have been identified as natural reservoirs of many viruses Some of these viruses cause outbreaks of severe disease in humans [2], including the Ebola virus, the lyssavirus, the severe acute respiratory syndrome coronavirus, and henipaviruses [3]. These viruses rarely cause apparent clinical signs in bats [2]. In recent years, several hepatitis virus-related sequences, including those associated with hepadnaviruses, hepeviruses, hepatoviruses, and hepaciviruses, have been found in bats across the globe, indicating the importance of bats as the natural reservoirs of these viruses [5–9]

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