Virome comparisons in wild-diseased and healthy captive giant pandas

Wen Zhang,Li Cui,Hua Wang,Feifei Feng,Lianghua Guo,Peng Chen,Yin Shen ,Dunwu Qi,Chao Chen,Zhijian Liu,Zhihe Zhang,Wang Li,Xiuguo Hua,Shixing Yang,Xutao Deng,Yan Wang,Chenglin Zhou,Tongling Shan,Xiaochun Wang,Rong Hou,Eric Delwart

doi:10.1186/s40168-017-0308-0

Abstract

BackgroundThe giant panda (Ailuropoda melanoleuca) is a vulnerable mammal herbivore living wild in central China. Viral infections have become a potential threat to the health of these endangered animals, but limited information related to these infections is available.MethodsUsing a viral metagenomic approach, we surveyed viruses in the feces, nasopharyngeal secretions, blood, and different tissues from a wild giant panda that died from an unknown disease, a healthy wild giant panda, and 46 healthy captive animals.ResultsThe previously uncharacterized complete or near complete genomes of four viruses from three genera in Papillomaviridae family, six viruses in a proposed new Picornaviridae genus (Aimelvirus), two unclassified viruses related to posaviruses in Picornavirales order, 19 anelloviruses in four different clades of Anelloviridae family, four putative circoviruses, and 15 viruses belonging to the recently described Genomoviridae family were sequenced. Reflecting the diet of giant pandas, numerous insect virus sequences related to the families Iflaviridae, Dicistroviridae, Iridoviridae, Baculoviridae, Polydnaviridae, and subfamily Densovirinae and plant viruses sequences related to the families Tombusviridae, Partitiviridae, Secoviridae, Geminiviridae, Luteoviridae, Virgaviridae, and Rhabdoviridae; genus Umbravirus, Alphaflexiviridae, and Phycodnaviridae were also detected in fecal samples. A small number of insect virus sequences were also detected in the nasopharyngeal secretions of healthy giant pandas and lung tissues from the dead wild giant panda. Although the viral families present in the sick giant panda were also detected in the healthy ones, a higher proportion of papillomaviruses, picornaviruses, and anelloviruses reads were detected in the diseased panda.ConclusionThis viral survey increases our understanding of eukaryotic viruses in giant pandas and provides a baseline for comparison to viruses detected in future infectious disease outbreaks. The similar viral families detected in sick and healthy giant pandas indicate that these viruses result in commensal infections in most immuno-competent animals.

Highlights

The giant panda (Ailuropoda melanoleuca) is a vulnerable mammal herbivore living wild in central China
In order to elucidate whether a viral infection was related to this animal’s condition, feces, blood and nasopharyngeal secretion were collected prior to its death and heart, liver, spleen, lung, and kidney tissues collected after its death
Viral metagenomics has recently been used in numerous animal virus discoveries [14, 30, 59,60,61,62], providing information on the composition of animal viromes, helping to provide candidates to identify the etiology of infectious disease in animals and identify zoonotic and emerging viruses

Summary

Introduction

The giant panda (Ailuropoda melanoleuca) is a vulnerable mammal herbivore living wild in central China. The State Forestry Administration of China reported 1864 wild giant pandas in the fourth national survey, representing a 16.8% increase over the previous decade resulting in its re-categorization as vulnerable in the International Union for Conservation of Nature’s Red List of Threatened Species. A low reproductive success and infectious diseases have hampered the development of captive and wild populations of the giant panda. Changes in the population or habitat of giant pandas may place animals at increased risk of infectious disease and hinder conservation efforts. The future of the endangered giant pandas depends in part on the development of protective measures against infectious diseases, especially viral infection. Multiple studies of the bacterial content of giant panda feces have been reported [4,5,6,7,8], virologic study of giant panda has been limited to the identification and pathogenicity of single viruses including canine distemper virus, canine parvovirus, and influenza H1N1 [9,10,11]

Methods

Results

Discussion

Conclusion