Selasa, 18 Oktober 2011

Virus Famili Anelloviridae

he Anelloviridae are a recently discovered family of viruses . They are classified as a vertebrate viruses and have a non-enveloped capsid, which is round with isometric, icosahedral symmetry.

The genome is not segmented and contains a single molecule of circular, negative-sense, single-stranded DNA. The complete genome is 3000-4000 nucleotides long.a

The type species is torque teno virus. Anellovirus species are highly prevalent and genetically diverse. They cause chronic human viral infections that have not yet been associated with diseaseAncient human remains are potential sources of biological information including traces of past infections, since previous studies have demonstrated the effective detection of several bacterial agents or host-integrated viruses in old biological remnants like tissues or teeth. Studies of skeletal dental pulp samples are of particular interest since this location is potentially exposed to bloodborne agents during life through its vascularization, and could be considered as well preserved from environment after death of the host. DNA viruses belonging to the family Anelloviridae are highly present in human populations where they harbor an extreme genetic diversity but a yet undefined implication in hosts' health. We hypothesized that anelloviruses would be detected in ancient remains and that they may also serve as tracer viruses for the study of other viral agents. We analyzed 200-year-old dental pulp samples from remains of soldiers of Napoleon's Great Army during the Russian Retreat. Successful detection of Anelloviridae DNA by PCR was obtained for 1/21 ancient samples tested. The sequence identified showed 23% nucleotide divergence with the closest group of modern isolates (genus Gammatorquevirus), and was confirmed as phylogenetically distinct from those identified in saliva samples from the two investigators in charge of the study (genera Alphatorquevirus and Betatorquevirus). PCR directed toward the human beta globin gene was also performed. Negative controls were negative. Our results demonstrate that an ubiquitary, non-integrated, DNA virus is detectable from ancient biological material, with potential developments in terms of evolution studies or subsequent molecular investigations involving further viral agents.

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