Sequence analysis of E/NS1 gene junction of Dengue Type-1 viruses isolated in Klang Valley 2010 to 2012
- Author:
Nur Liyana, K., Fauziah, M.K., Zainah, S., Nor Aziyah R., and Thayan, R.
- Publication Type:Journal Article
- From:Tropical Biomedicine
2016;33(2):348-358
- CountryMalaysia
- Language:English
-
Abstract:
Dengue is a mosquito-borne viral disease caused by four serotypes of dengue
virus, affecting the human population for decades in many tropical and subtropical regions of
the world. In Malaysia, all four dengue serotypes co-circulates in a dengue season even
though any one of the serotypes can predominate. In this study, serum samples were collected
from dengue fever and severe dengue fever patients within Klang Valley from 2010-2012 to
determine the prevailing dengue serotypes. In addition, sequencing of the envelope/nonstructural
1 (E/NS1) gene junction of the virus isolated was performed to identify the presence
of any mutations that are suggestive of increased virulence in the virus. The results showed
that Dengue-1 (DEN-1) was the predominant circulating serotype. The E/NS1 gene sequences
of the isolates were analysed to trace the evolutionary knowledge of the strains. All sequences
of the isolates were compared with DEN-1 prototype Hawaii strain as the reference sequence.
The E/NS1 sequences of other dengue strains from neighbouring regions as well as other
parts of the world obtained from the GenBank database were also included in the phylogenetic
tree analysis. Analyses showed that there was 97% to 100% similarity among the ten isolates
at the nucleotide level. Similarly, the amino acid analogue also showed 98% to 100% homology.
However, all five non-severe dengue isolates showed variation at position 780, resulting in an
amino acid change from valine to alanine as compared to severe dengue isolates. A rooted
phylogenetic tree was performed using neighbour-joining method with DEN-2 and DEN-3 as
the outgroups. Results showed that all ten isolates were classified as genotype I. In addition,
the five isolates from severe dengue patients were found to be clustered together with
JN697057 and JN697058, Malaysian DEN-1 strains from the 2005 outbreak.
- Full text:P020160901593848368825.pdf
