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See:
Cosavirus
Abstract from Kapoor et al.
(2008a):
Background:
RNA viruses implicated in acute flaccid paralysis (AFP) include
enteroviruses, echoviruses, coxsackieviruses and flaviviruses.
Existing molecular reagents frequently fail to identify highly
divergent variants or novel viruses.
Methods:
Stool samples from children presenting with AFP were used for virus
isolation in cell culture. Some virus isolates could not be
identified using serological and PCR assays. We used a metagenomic
shotgun sequencing approach and found several sequences in one
sample showing distant protein similarities to Picornaviruses. Large
scale sequencing (454 pyrosequencing) and RACE were used to acquire
the complete genome of a new virus, tentatively named Dekavirus
type-1. PCR primers targeting conserved nonstructural genes were
used to determine the prevalence of Dekavirus in stool samples from
children with AFP.
Results:
The Dekavirus genome codes for a single polyprotein flanked by 5’-
and 3’- non-translated regions, similar to all Picornaviruses.
Phylogenetic analysis of Dekavirus establishes it as an outlier
showing mean protein identity of only 16-32% to other genera of
Picornaviridae. Six genetic variants of Dekavirus were found in
14 stool samples from AFP children suggesting a high prevalence
among this disease group. The complete genome sequence also was
acquired from another divergent Dekavirus virus variant showing 82%
amino acid identity to Dekavirus type-1.
Conclusions:
We characterized two new Picornaviruses from AFP cases and
provisionally named them Dekavirus type 1 and type 2. Dekavirus
type-1 is divergent enough to be assigned as the prototype member of
a new genus in Picornaviridae. A large study based on PCR
detection and serology is underway to determine if Dekaviruses are
linked to AFP.
Abstract from Kapoor et al.
(2008b):
Despite the near eradication of poliovirus,
acute flaccid paralysis (AFP) of viral etiology still inflicts
frequent, severe, and at time permanent damages to children,
particularly in developing countries with poor sanitation. No
viruses have been identified for over half of the remaining cases of
non-polio AFP. This study describes identification and molecular
characterization of novel picornaviruses from stool samples of
children with non-polio AFP. Partial genome of 29 and complete
genome of 5 new picornaviruses were acquired and phylogenetic
analysis indicated them to be sufficiently divergent from all
currently known picornaviruses to qualify as members of a new
proposed genus Dekavirus (DKV) in the Picornaviridae family.
All DKV variants sequenced lacked leader peptide coding region that
is characteristic feature of other closely related genera. Our
results indicate that DKVs can be classified in four virus species
showing <60% amino acid identity in P3 gene comparable to that
reported between species of human enteroviruses (HEV). The wide
range of genetic diversity exhibited both within and between the
Dekaviruses species also supports the possibility that, like HEVs,
they may be involved in a variety of clinical manifestations.
References
Kapoor, A., Victoria, J.G., Naeem, A., Sharif, S., Shaukat, S.,
Masroor, M., Angez, M., Wang, C., Shafer, R.W., Zaidi, S.Z. and
Delwart, E.L. (2008a). Characterization of a highly divergent picornavirus prevalent in stool samples of children with acute
flaccid paralysis. [abstract]. International Conference on Emerging
Infectious Diseases 2008: slide sessions and poster abstracts.
Emerging Infectious Diseases [serial on the Internet]. 2008 Mar
14. Available from
http://www.cdc.gov/eid/content/14/3/ICEID2008.pdf.Kapoor, A., Victoria, J.G.,
Simmonds, P., Naeem, A., Sharif, S., Shaukat, S.,
Masroor, M., Angez, M., Wang, C., Shafer, R.W., Zaidi, S.Z. and
Delwart, E.L. (2008b). Characterization of a highly divergent picornavirus
prevalent in stool samples of children with acute flaccid paralysis.
Poster presented at EUROPIC 2008: XVth Meeting in Sitges,
Barcelona, Spain, 26-30th May 2008
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