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 w...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 wa.s investigated by the likelihood mapping analysis.The Bayesian phylogenetic tree was built using BEAST.Results:The phylogenetic trees showed two main clades.The clade Ⅰincluding 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 wa.s0.407 × 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.展开更多
Objective:To explore the genetic diversity and the modification of antibody response in the recent outbreak of Ebola Virus.Methods:Sequences retrieved from public databases,the selective pressure analysis and the homo...Objective:To explore the genetic diversity and the modification of antibody response in the recent outbreak of Ebola Virus.Methods:Sequences retrieved from public databases,the selective pressure analysis and the homology modelling based on the all protein(nucleoprotein.VP35,VP40.soluble glycoprotein,small soluble glycoprotein.VP30,VP24 and polymerase) were used.Results:Structural proteins VP24.VP30.VP35 and VP40 showed relative conserved sequences making them suitable target candidates for antiviral treatment.On the contrary,nucleoprotein.polymerase and soluble glycoprotein have high mutation frequency.Conclusions:Data from this study point out important aspects of Ebola virus sequence variability that for epitope and vaccine design should be considered for appropriate targeting of conserved protein regions.展开更多
Objective: To investigate the genetic diversity of Zika virus(ZIKV) and the relationships existing among these circulating viruses worldwide. To evaluate the genetic polymorphisms harboured from ZIKV that can have an ...Objective: To investigate the genetic diversity of Zika virus(ZIKV) and the relationships existing among these circulating viruses worldwide. To evaluate the genetic polymorphisms harboured from ZIKV that can have an influence on the virus circulation. Methods: Three different ZIKV dataset were built. The first dataset included 63 E gene sequences, the second one 22 NS3 sequences and the third dataset was composed of 108 NS5 gene sequences. Phylogenetic and selective pressure analysis was performed. The edited nucleic acid alignment from the Envelope dataset was used to generate a conceptual translation to the corresponding peptide sequences through UGene software. Results: The phylogeographic reconstruction was able to discriminate unambiguously that the Brazilian strains are belonged to the Asian lineage. The structural analysis reveals instead the presence of the Ser residue in the Brazilian sequences(however already observed in other previously reported ZIKV infections) that could suggest the presence of a neutralization-resistant population of viruses. Conclusions: Phylogenetic, evolutionary and selective pressure analysis contributed to improve the knowledge on the circulation of ZIKV.展开更多
文摘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 wa.s investigated by the likelihood mapping analysis.The Bayesian phylogenetic tree was built using BEAST.Results:The phylogenetic trees showed two main clades.The clade Ⅰincluding 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 wa.s0.407 × 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.
基金supported by National Institute of Health andProxagent Ltd in collaboration with University of Rome "Tor Vergata
文摘Objective:To explore the genetic diversity and the modification of antibody response in the recent outbreak of Ebola Virus.Methods:Sequences retrieved from public databases,the selective pressure analysis and the homology modelling based on the all protein(nucleoprotein.VP35,VP40.soluble glycoprotein,small soluble glycoprotein.VP30,VP24 and polymerase) were used.Results:Structural proteins VP24.VP30.VP35 and VP40 showed relative conserved sequences making them suitable target candidates for antiviral treatment.On the contrary,nucleoprotein.polymerase and soluble glycoprotein have high mutation frequency.Conclusions:Data from this study point out important aspects of Ebola virus sequence variability that for epitope and vaccine design should be considered for appropriate targeting of conserved protein regions.
文摘Objective: To investigate the genetic diversity of Zika virus(ZIKV) and the relationships existing among these circulating viruses worldwide. To evaluate the genetic polymorphisms harboured from ZIKV that can have an influence on the virus circulation. Methods: Three different ZIKV dataset were built. The first dataset included 63 E gene sequences, the second one 22 NS3 sequences and the third dataset was composed of 108 NS5 gene sequences. Phylogenetic and selective pressure analysis was performed. The edited nucleic acid alignment from the Envelope dataset was used to generate a conceptual translation to the corresponding peptide sequences through UGene software. Results: The phylogeographic reconstruction was able to discriminate unambiguously that the Brazilian strains are belonged to the Asian lineage. The structural analysis reveals instead the presence of the Ser residue in the Brazilian sequences(however already observed in other previously reported ZIKV infections) that could suggest the presence of a neutralization-resistant population of viruses. Conclusions: Phylogenetic, evolutionary and selective pressure analysis contributed to improve the knowledge on the circulation of ZIKV.