Two novel circo-like viruses detected in human feces: complete genome sequencing and electron microscopy analysis
Autor: | Marli Ueda-Ito, Suely Pires Curti, Teresa Keico Nagasse-Sugahara, Paulo Eduardo Brandão, Jonas José Kisielius, Silvana Beres Castrignano |
---|---|
Rok vydání: | 2013 |
Předmět: |
Cancer Research
viruses Molecular Sequence Data Genome Viral GENOMAS Genome Feces Open Reading Frames Phylogenetics Virology Cluster Analysis Humans Geminiviridae ORFS Phylogeny Circoviridae Genetics Whole genome sequencing Sequence Homology Amino Acid biology Virion Sequence Analysis DNA Middle Aged biology.organism_classification Microscopy Electron Infectious Diseases Rolling circle replication DNA Viral Nanoviridae Female Brazil |
Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
ISSN: | 0168-1702 |
Popis: | The application of viral metagenomic techniques and a series of PCRs in a human fecal sample enabled the detection of two novel circular unisense DNA viral genomes with 92% nucleotide similarity. The viruses were tentatively named circo-like virus-Brazil (CLV-BR) strains hs1 and hs2 and have genome lengths of 2526 and 2533 nucleotides, respectively. Four major open reading frames (ORFs) were identified in each of the genomes, and differences between the two genomes were primarily observed in ORF 2. Only ORF 3 showed significant amino acid similarities to a putative rolling circle replication initiator protein (Rep), although with low identity (36%). Our phylogenetic analysis, based on the Rep protein, demonstrated that the CLV-BRs do not cluster with members of the Circoviridae, Nanoviridae or Geminiviridae families and are more closely related to circo-like genomes previously identified in reclaimed water and feces of a wild rodent and of a bat. The CLV-BRs are members of a putative new family of circular Rep-encoding ssDNA viruses. Electron microscopy revealed icosahedral (~23 nm) structures, likely reflecting the novel viruses, and rod-shaped viral particles (~65-460 × 21 × 10 nm in length, diameter, and axial canal, respectively). Circo-like viruses have been detected in stool samples from humans and other mammals (bats, rodents, chimpanzees and bovines), cerebrospinal fluid and sera from humans, as well as samples from many other sources, e.g., insects, meat and the environment. Further studies are needed to classify all novel circular DNA viruses and elucidate their hosts, pathogenicity and evolutionary history. |
Databáze: | OpenAIRE |
Externí odkaz: |