Phylogeography of crimean congo hemorrhagic fever virus

Crimean Congo hemorrhagic fever virus (CCHFV) is one of the most severe viral zoonozes. It is prevalent throughout Africa, Asia and southern Europe. Limited availability of sequence data has hindered phylogeographic studies. The complete genomic sequence of all three segments of 14 Crimean Congo hemorrhagic fever virus strains isolated from 1958-2000 in Russia, Central Asia and Africa was identified. Each genomic segment was independently subjected to continuous Bayesian phylogeographic analysis. The origin of each genomic segment was traced to Africa about 1,000-5,000 years ago. The virus was first introduced to South and Central Asia in the Middle Ages, and then spread to China, India and Russia. Reverse transfers of genomic segments from Asia to Africa were also observed. The European CCHFV genotype V was introduced to Europe via the Astrakhan region in South Russia 280-400 years ago and subsequently gradually spread westward in Russia, to Turkey and the Balkans less than 150 years ago. Only a few recombination events could be suggested in S and L genomic segments, while segment reassortment was very common. The median height of a non-reassortant phylogenetic tree node was 68-156 years. There were reassortment events within the European CCHFV lineage, but not with viruses from other locations. Therefore, CCHFV in Europe is a recently emerged zoonosis that represents a spillover from the global gene pool. © 2016 Lukashev et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Phylogeography of crimean congo hemorrhagic fever virus

Crimean Congo hemorrhagic fever virus (CCHFV) is one of the most severe viral zoonozes. It is prevalent throughout Africa, Asia and southern Europe. Limited availability of sequence data has hindered phylogeographic studies. The complete genomic sequence of all three segments of 14 Crimean Congo hemorrhagic fever virus strains isolated from 1958-2000 in Russia, Central Asia and Africa was identified. Each genomic segment was independently subjected to continuous Bayesian phylogeographic analysis. The origin of each genomic segment was traced to Africa about 1,000-5,000 years ago. The virus was first introduced to South and Central Asia in the Middle Ages, and then spread to China, India and Russia. Reverse transfers of genomic segments from Asia to Africa were also observed. The European CCHFV genotype V was introduced to Europe via the Astrakhan region in South Russia 280-400 years ago and subsequently gradually spread westward in Russia, to Turkey and the Balkans less than 150 years ago. Only a few recombination events could be suggested in S and L genomic segments, while segment reassortment was very common. The median height of a non-reassortant phylogenetic tree node was 68-156 years. There were reassortment events within the European CCHFV lineage, but not with viruses from other locations. Therefore, CCHFV in Europe is a recently emerged zoonosis that represents a spillover from the global gene pool. © 2016 Lukashev et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Robustness against serum neutralization of a poliovirus type 1 from a lethal epidemic of poliomyelitis in the Republic of Congo in 2010

In 2010, a large outbreak of poliomyelitis with unusual 47% lethality occurred in Pointe Noire, Republic of Congo. Vaccine-mediated immunity against the outbreak virus was never investigated. A wild poliovirus 1 (WPV1) isolated from a fatal case (termed PV1-RC2010) showed a previously unknown combination of amino acid exchanges in critical antigenic site 2 (AgS2, VP1 capsid protein positions (221)SAAL ->(221)PADL). These exchanges were also detected in an additional 11 WPV1 strains from fatal cases. PV1-RC2010 escaped neutralization by three different mAbs relevant for AgS2. Virus neutralization was tested in sera from fatal cases, who died before supplementary immunization (n = 24), Gabonese recipients of recent oral polio vaccination (n = 12), routinely vaccinated German medical students (n = 34), and German outpatients tested for anti-poliovirus immunity (n = 17) on Vero, human rhabdomyosarcoma, and human epidermoid carcinoma 2 cells. Fatal poliomyelitis cases gave laboratory evidence of previous trivalent vaccination. Neutralizing antibody titers against PV1-RC2010 were significantly lower than those against the vaccine strain Sabin-1, two genetically distinct WPV1s isolated in 1965 and 2010 and two genetically distinct vaccine-derived PV strains. Of German vaccinees tested according to World Health Organization protocols, 15-29% were unprotected according to their neutralization titers (<1: 8 serum dilution), even though all were protected against Sabin-1. Phylogenetic analysis of the WPV1 outbreak strains suggested a recent introduction of virus progenitors from Asia with formation of separate Angolan and Congolese lineages. Only the latter carried both critical AgS2 mutations. Antigenetically variant PVs may become relevant during the final phase of poliomyelitis eradication in populations with predominantly vaccine-derived immunity. Sustained vaccination coverage and clinical and environmental surveillance will be necessary

Evolution of 2B and 2C genomic parts of species B Coxsackie viruses. Phylogenetic study and comparison with other regions

Modern molecular approaches on the genome of enteroviruses' circulating strains have established new data about the mechanism and significance of its evolution. In the present study, 46 enteroviruses isolates, belonging to HEV-B species and exhibiting distinct origin in geographical or chronological terms, were investigated concerning their primary structure and phylogeny. Two regions of the aforementioned strains genome, which have not been thoroughly investigated (2B and 5′ extreme of 2C) were amplified and sequenced for the first time. Phylogenetic and nucleotide analysis of the isolates' fragments, along with representative prototype sequences, demonstrate that the classification scheme of monophyly and accordance with the genotype, which characterizes VP1 region, is seriously disturbed. Moreover, the phylogenetic trees constructed from adjacent regions of the genome appear radically incongruent suggesting that the parameters that affect these portions are different or act in a different extent. Our study results an additional step in the study of enteroviruses evolution and inheritance, by investigating unstudied regions of newly sequenced strains and revealing that the primary structure and phylogeny of them is different not only comparably to the structural genome but also from one to another. © Springer Science+Buisness Media, Inc. 2006

Partial 3D gene sequences of Coxsackie viruses reveal interspecies exchanges

The 3D region of 46 clinical Coxsackievirus strains, primarily belonging to the human enterovirus B species (HEV-B), were analyzed using nucleotide distance matrices and phylogeny software. The conclusions from previously analyzed genomic regions (VP1-2A-2B-2C) of the aforementioned strains revealed that enteroviruses' inheritance is being guided by gene adaptation among viruses of different serotypes. In this report the comparison of partial VP1 and 3D gene phylogenies presented an obvious incongruence. Moreover, the phylogeny of 3D sequences of the strains revealed an unexpected (and for the first time reported) homology among strains of different species. The observations of our study indicate that conversion events such as multiple mutations or recombination among strains and unknown donors may occur during the evolution of circulating strains, leading, probably, to viruses with altered genome and virulence. © 2007 Springer Science+Business Media, LLC