Redondoviruses (members of theRedondoviridae) are a family of human-associatedDNA viruses.[2] Their name derives from the inferred circular structure of the viralgenome (“redondo” means round inSpanish). Redondoviruses have been identified in DNA sequence based surveys of samples from humans, primarily samples from the oral cavity and upper airway.[3][4][5]
The familyRedondoviridae contains one genus,Torbevirus, which contains two species,Brisavirus (Torbevirus brisa) andVientovirus (Torbevirus viento).[1][5] The names derive from the words for breeze and wind in Spanish (“brisa” and “viento”), denoting the association with the human airway.[2]
The redondoviruses are members of the Circular Rep-Containing Single Stranded (CRESS) DNA Virus group.[7]
The redondovirus genome is circular, and by analogy to other CRESS viruses likely single stranded. Genomes are about 3.0 kilobases in size. The genome encodes three inferred proteins:[2]
Redondovirus genomes have been reported primarily from human samples surveyed usingmetagenomic DNA sequencing. They have been found primarily in oral and airway specimens.[4][5]In some human populations, oral samples can show up to 80% Redondovirus positivity.[10]
Analysis of a variety of human-derived sample types showed a strong positive correlation of Redondovirus DNA and DNA of the oral amoebaEntamoeba gingivalis. Follow up studies showed that a xenic culture containingEntamoeba gingivalis and feeder bacteria was also positive for redondovirus DNA and RNA. Analysis using intracellular cross linking (Hi-C) showed crosslinking of redondovirus DNA toEntamoeba DNA, supportingEntamoeba gingivalis as the host.[11][12]
It is unknown whether redondoviruses cause human disease. Some CRESS viruses are known pathogens, such asporcine circovirus type 2.[13]
Redondoviruses have been reported associated withperiodontitis. In one study, the levels fell with successful treatment.[5] Abundance of redondovirus genomes has also been found to be high in some intensive care unit patients, and in patients with severe COVID-19.[14] At present the basis of these disease associations is unclear.[1][5]
^abCui L, Wu B, Zhu X, Guo X, Ge Y, Zhao K, Qi X, Shi Z, Zhu F, Sun L, Zhou M (November 2017). "Identification and genetic characterization of a novel circular single-stranded DNA virus in a human upper respiratory tract sample".Archives of Virology.162 (11):3305–3312.doi:10.1007/s00705-017-3481-3.ISSN0304-8608.PMID28707271.S2CID9239411.
^Zhao L, Rosario K, Breitbart M, Duffy S (2019), "Eukaryotic Circular Rep-Encoding Single-Stranded DNA (CRESS DNA) Viruses: Ubiquitous Viruses With Small Genomes and a Diverse Host Range",Advances in Virus Research,103, Elsevier:71–133,doi:10.1016/bs.aivir.2018.10.001,ISBN978-0-12-817722-8,PMID30635078,S2CID58636379{{citation}}: CS1 maint: work parameter with ISBN (link)
Data related toRedondoviridae at Wikispecies