Diverse DNA virus genomes identified in fecal samples of Mexican free-tailed bats (Tadarida brasiliensis) captured in Chiricahua Mountains of southeast Arizona (USA).

Bats (order Chiroptera) are some of the most abundant mammals on earth and their species ecology strongly influences zoonotic potential. While substantial research has been conducted on bat-associated viruses, particularly on those that can cause disease in humans and/or livestock, globally, limited research has focused on endemic bats in the USA. The southwest region of the US is of particular interest because of its high diversity of bat species. We identified 39 single-stranded DNA virus genomes in the feces of Mexican free-tailed bats (Tadarida brasiliensis) sampled in the Rucker Canyon (Chiricahua Mountains) of southeast Arizona (USA). Twenty-eight of these belong to the virus families Circoviridae (n = 6), Genomoviridae (n = 17), and Microviridae (n = 5). Eleven viruses cluster with other unclassified cressdnaviruses. Most of the viruses identified represent new species. Further research on identification of novel bat-associated cressdnaviruses and microviruses is needed to provide greater insights regarding their co-evolution and ecology relative to bats.

Novel lineages of single-stranded DNA phages that coevolved with the symbiotic bacteria Rhizobium.

This study describes novel single-stranded DNA phages isolated from common bean agriculture soils by infection of the nitrogen-fixing symbiotic bacteria Rhizobium etli and R. phaseoli. A total of 29 phages analyzed have 4.3-6 kb genomes in size and GC 59-60%. They belong to different clades unrelated to other Microviridae subfamilies. Three-dimensional models of the major capsid protein (MCP) showed a conserved ß-barrel structural "jelly-roll" fold. A variable-length loop in the MCPs distinguished three Rhizobium microvirus groups. Microviridae subfamilies were consistent with viral clusters determined by the protein-sharing network. All viral clusters, except for Bullavirinae, included mostly microviruses identified in metagenomes from distinct ecosystems. Two Rhizobium microvirus clusters, chaparroviruses, and chicoviruses, were included within large viral unknown clusters with microvirus genomes identified in diverse metagenomes. A third Rhizobium microvirus cluster belonged to the subfamily Amoyvirinae. Phylogenetic analysis of the MCP confirms the divergence of the Rhizobium microviruses into separate clades. The phylogeny of the bacterial hosts matches the microvirus MCP phylogeny, suggesting a coevolutionary history between the phages and their bacterial host. This study provided essential biological information on cultivated microvirus for understanding the evolution and ecological diversification of the Microviridae family in diverse microbial ecosystems.

Single Stranded DNA Viruses Associated with Capybara Faeces Sampled in Brazil.

Capybaras (Hydrochoerus hydrochaeris), the world's largest rodents, are distributed throughout South America. These wild herbivores are commonly found near water bodies and are well adapted to rural and urban areas. There is limited information on the viruses circulating through capybaras. This study aimed to expand the knowledge on the viral diversity associated with capybaras by sampling their faeces. Using a viral metagenomics approach, we identified diverse single-stranded DNA viruses in the capybara faeces sampled in the Distrito Federal, Brazil. A total of 148 complete genomes of viruses in the Microviridae family were identified. In addition, 14 genomoviruses (family Genomoviridae), a novel cyclovirus (family Circoviridae), and a smacovirus (family Smacoviridae) were identified. Also, 37 diverse viruses that cannot be assigned to known families and more broadly referred to as unclassified circular replication associated protein encoding single-stranded (CRESS) DNA viruses were identified. This study provides a snapshot of the viral diversity associated with capybaras that may be infectious to these animals or associated with their microbiota or diet.