(1) Background: Over the last few years, there has been growing interest in the whole genome sequencing (WGS) of rapidly mutating pathogens, such as influenza viruses (IVs), which has led us to carry out in-depth studies on viral evolution in both research and diagnostic settings. We aimed at describing and determining the validity of a WGS protocol that can obtain the complete genome sequence of A(H3N2) IVs directly from clinical specimens. (2) Methods: RNA was extracted from 80 A(H3N2)-positive respiratory specimens.
View Article and Find Full Text PDFThe nucleotide analog sofosbuvir, licensed for the treatment of hepatitis C, recently revealed activity against the Zika virus (ZIKV) in vitro and in animal models. However, the ZIKV genetic barrier to sofosbuvir has not yet been characterized. In this study, in vitro selection experiments were performed in infected human hepatoma cell lines.
View Article and Find Full Text PDFLineage 2 West Nile virus (WNV) caused a vast epidemic in Europe in 2018, with the highest incidence being recorded in Italy. To reconstruct the evolutionary dynamics and epidemiological history of the virus in Italy, 53 envelope gene and 26 complete genome sequences obtained from human and animal samples were characterised by means of next-generation sequencing. Phylogenetic analysis revealed two Italian strains originating between 2010 and 2012: clade A, which apparently became extinct in 2013-2014, and clade B, which was responsible for the 2018 epidemic.
View Article and Find Full Text PDFZika virus (ZIKV), a vector-borne infectious agent that has recently been associated with neurological diseases and congenital microcephaly, was first reported in the Western hemisphere in early 2015. A number of authors have reconstructed its epidemiological history using advanced phylogenetic approaches, and the majority of Zika phylogeography studies have used discrete diffusion models. Continuous space diffusion models make it possible to infer the possible origin of the virus in real space by reconstructing its ancestral location on the basis of geographical coordinates deduced from the latitude and longitude of the sampling locations.
View Article and Find Full Text PDFVariola virus (VARV), the causative agent of smallpox, is an exclusively human virus belonging to the genus Orthopoxvirus, which includes many other viral species covering a wide range of mammal hosts, such as vaccinia, cowpox, camelpox, taterapox, ectromelia, and monkeypox virus. The tempo and mode of evolution of Orthopoxviruses were reconstructed using a Bayesian phylodynamic framework by analysing 80 hemagglutinin sequences retrieved from public databases. Bayesian phylogeography was used to estimate their putative ancestral hosts.
View Article and Find Full Text PDFWest Nile virus lineage 2 (WNV-2) was mainly confined to sub-Saharan Africa until the early 2000s, when it was identified for the first time in Central Europe causing outbreaks of human and animal infection. The aim of this study was to reconstruct the origin and dispersion of WNV-2 in Central Europe and Italy on a phylodynamic and phylogeographical basis. To this aim, discrete and continuous space phylogeographical models were applied to a total of 33 newly characterised full-length viral genomes obtained from mosquitoes, birds and humans in Northern Italy in the years 2013-2015 aligned with 64 complete sequences isolated mainly in Europe.
View Article and Find Full Text PDFBorder disease virus (BDV) affects a wide range of ruminants worldwide, mainly domestic sheep and goat. Since 2001 several outbreaks of disease associated to BDV infection have been described in Pyrenean chamois (Rupicapra pyrenaica pyrenaica) in Spain, France and Andorra. In order to reconstruct the most probable places of origin and pathways of dispersion of BDV among Pyrenean chamois, a phylogenetic analysis of 95 BDV 5'untranslated sequences has been performed on chamois and domestic ungulates, including novel sequences and retrieved from public databases, using a Bayesian Markov Chain Monte Carlo method.
View Article and Find Full Text PDFJ Glob Infect Dis
September 2016
Context: Human immunodeficiency virus type 2 (HIV-2) infections are mainly restricted to West Africa; however, in the recent years, the prevalence of HIV-2 is a growing concern in some European countries and the Southwestern region of India. Despite the presence of different HIV-2 groups, only A and B Groups have established human-to-human transmission chains.
Aims: This work aimed to evaluate the phylogeographic inference of HIV-2 Group B worldwide to estimate their data of origin and the population dynamics.
The aim of this study was to investigate the origin and geographical dispersion of Marburg virus, the first member of the Filoviridae family to be discovered. Seventy-three complete genome sequences of Marburg virus isolated from animals and humans were retrieved from public databases and analysed using a Bayesian phylogeographical framework. The phylogenetic tree of the Marburg virus data set showed two significant evolutionary lineages: Ravn virus (RAVV) and Marburg virus (MARV).
View Article and Find Full Text PDFBackground: Influenza A viruses are characterised by their rapid evolution, and the appearance of point mutations in the viral hemagglutinin (HA) domain causes seasonal epidemics. The A(H3N2) virus has higher mutation rate than the A(H1N1) virus. The aim of this study was to reconstruct the evolutionary dynamics of the A(H3N2) viruses circulating in Italy between 2004 and 2012 in the light of the forces driving viral evolution.
View Article and Find Full Text PDFThe worldwide distributed Hepatitis B virus (HBV) genotype A is classified into three subgenotypes, and one quasi-subgenotype. The majority of HBV-A subgenotypes are widespread in Africa and in ethnic groups that have relatively recently emigrated from African countries, whereas HBV-A2 is highly prevalent among subjects at high risk for sexual exposure to HBV in north-western Europe and the USA. The aim of this study was to reconstruct the origin and dispersion of HBV-A subgenotypes on a reliable timescale using short-term calibration based on heterochronous sampling for HBV-A2, and long-term calibration based on historical data for the other subgenotypes.
View Article and Find Full Text PDFThe Mediterranean area and the Balkans in particular show the highest level of genetic heterogeneity of HBV in Europe. Data about the circulation of HBV genotypes in Montenegro are lacking. It was studied the prevalence and distribution of HBV genot/subgenotypes in a total of 150 HBV infected patients living in Montenegro.
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