Complex evolution and epidemiology of Dobrava-Belgrade hantavirus: definition of genotypes and their characteristics

Abstract

Dobrava-Belgrade virus (DOBV) is a human pathogen that has evolved in, and is hosted by, mice of several species of the genus Apodemus. We propose a subdivision of the species Dobrava-Belgrade virus into four related genotypes - Dobrava, Kurkino, Saaremaa, and Sochi - that show characteristic differences in their phylogeny, specific host reservoirs, geographical distribution, and pathogenicity for humans.

Fig. 1

Maximum-likelihood phylogenetic trees showing the phylogenetic position of Dobrava-Belgrade virus genotypes (marked by light grey boxes) constructed on the basis of complete nucleocapsid protein (S segment) coding sequences (A) and complete glycoprotein precursor (M segment) coding sequences (B). Evolutionary analysis was conducted in MEGA5 [78]. The evolutionary history was inferred using the maximum-likelihood method based on the general time-reversible (GTR) model with a discrete Gamma distribution (+G) and five rate categories, and by assuming that a certain fraction of sites are evolutionarily invariable (+I), which was estimated to be the best-fit substitution model according to the Bayesian information criterion. The scale bars indicate an evolutionary distance of 0.1 substitutions per position in the sequence. Bootstrap values ≥70 %, calculated from 500 replicates, are shown at the tree branches, Bayesian posterior probability values ≥0.7 of the corresponding Bayesian phylogenetic tree are shown below the branches. Bayesian trees were estimated using the program BEAST with the nucleotide substitution model GTR+G+I. HTNV, Hantaan virus; SANGV, Sangassou virus; SEOV, Seoul virus; THAIV, Thailand virus

Fig. 2

Phylogenetic tree of Dobrava-Belgrade virus strains belonging to the four genotypes (marked by light grey boxes), based on partial S segment sequences (575 bp) and showing all currently available DOBV S segment sequences of sufficient length. For methodological details of the evolutionary analysis, see legend to Fig. 1. The scale bars indicate an evolutionary distance of 0.1 substitutions per position in the sequence. Bootstrap values ≥ 70 %, calculated from 500 replicates, are shown at the tree branches; Bayesian posterior probability values ≥ 0.7 of the corresponding Bayesian phylogenetic tree are shown below the branches. Bayesian trees were estimated using the program BEAST with the nucleotide substitution model GTR + G+I. HTNV, Hantaan virus; SANGV, Sangassou virus; SEOV, Seoul virus; THAIV, Thailand virus