A novel group of avian astroviruses from Neotropical passerine birds broaden the diversity and host range of Astroviridae

Abstract

La metagenómica está ampliando el conocimiento sobre la diversidad de virus, especialmente en hospedadores poco estudiados de regiones remotas. El análisis de muestras cloacales de aves neotropicales de la Guayana Francesa reveló cuatro genomas completos de astrovirus, que forman un nuevo clado monofilético divergente dentro de Avastrovirus y representan una posible nueva especie, denominada provisionalmente Avastrovirus 5. El análisis de 406 aves silvestres mostró una prevalencia comunitaria del 4,9%, que alcanzó el 5,1% en paseriformes. El estudio amplía el rango conocido de hospedadores de los astrovirus a seis familias de aves. Los resultados aportan información novedosa sobre la diversidad viral, ecología, epidemiología e interacciones entre hospedadores y patógenos que determinan la evolución de los avastrovirus en una selva neotropical remota.

Metagenomics is helping to expand the known diversity of viruses, especially of those with poorly studied hosts in remote areas. The Neotropical region harbors a considerable diversity of avian species that may play a role as both host and short-distance vectors of unknown viruses. Viral metagenomics of cloacal swabs from 50 Neotropical birds collected in French Guiana revealed the presence of four complete astrovirus genomes. They constitute an early diverging novel monophyletic clade within the Avastrovirus phylogeny, representing a putative new astrovirus species (provisionally designated as Avastrovirus 5) according to the International Committee on Taxonomy of Viruses (ICTV) classification criteria. Their genomic organization shares some characteristics with Avastrovirus but also with Mamastrovirus. The pan-astrovirus RT-PCR analysis of the cloacal samples of 406 wild Neotropical birds showed a community-level prevalence of 4.9% (5.1% in passerines, the highest described so far in this order of birds). By screening birds of a remote region, we expanded the known host range of astroviruses to the avian families Cardinalidae, Conopophagidae, Furnariidae, Thamnophilidae, Turdidae and Tyrannidae. Our results provide important first insights into the unexplored viral communities, the ecology, epidemiology and features of host-pathogen interactions that shape the evolution of avastroviruses in a remote Neotropical rainforest.