چکیده (انگلیسی):

Objective: To study the genetic diversity of Murray Valley encephalitis virus (MVEV)
in Australia and Papua New Guinea.
Methods: MVEV envelope gene sequences were aligned using Clustal X and manual
editing was performed with Bioedit. ModelTest v. 3.7 was used to select the simplest
evolutionary model that adequately fitted the sequence data. Maximum likelihood analysis
was performed using PhyML. The phylogenetic signal of the dataset was investigated
by the likelihood mapping analysis. The Bayesian phylogenetic tree was built using
BEAST.
Results: The phylogenetic trees showed two main clades. The clade Ⅰ including eight
strains isolated from West Australia. The clade Ⅱ was characterized by at least four
epidemic entries, three of which localized in Northern West Australia and one in Papua
New Guinea. The estimated mean evolutionary rate value of the MVEV envelope gene
was 0.407 × 10−3 substitution/site/year (95% HPD: 0.623 × 10−4
–0.780 × 10−3). Population
dynamics defines a relative constant population until the year 2000, when a
reduction occurred, probably due to a bottleneck.
Conclusions: This study has been useful in supporting the probable connection between
climate changes and viral evolution also by the vector point of view; multidisciplinary
monitoring studies are important to prevent new viral epidemics inside and outside new
endemic areas.