Phylogeny of Murray Valley encephalitis virus in Australia and Papua New Guinea

Eleonora Cella; Ivan Gabrielli; Gianguglielmo Zehender; Marta Giovanetti; Alessandra Lo Presti; Alessia Lai; Giordano Dicuonzo; Silvia Angeletti; Marco Salemi; Massimo Ciccozzi

doi:10.1016/j.apjtm.2016.03.006

Phylogeny of Murray Valley encephalitis virus in Australia and Papua New Guinea

Asian Pac J Trop Med. 2016 Apr;9(4):385-389. doi: 10.1016/j.apjtm.2016.03.006. Epub 2016 Mar 9.

Authors

Affiliations

¹ Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
² University of Rome 'La Sapienza', Italy.
³ L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Italy.
⁴ Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; University of Rome 'Tor Vergata', Italy.
⁵ Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy.
⁶ Clinical Pathology and Microbiology Laboratory, University Hospital Campus Bio-Medico of Rome, Italy.
⁷ Department of Pathology and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
⁸ Department of Infectious, Parasitic and Immunomediated Diseases, National Institute of Health, Rome, Italy; University Hospital Campus Bio-Medico, Rome, Italy. Electronic address: [email protected].

PMID: 27086158
DOI: 10.1016/j.apjtm.2016.03.006

Abstract

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.

Keywords: Evolution; Murray valley encephalitis virus; Phylogeny.