Fylogenetická a molekulární analýza virů chřipky A/H1N1pdm izolovaných v epidemické sezoně 2012/2013 od pacientů hospitalizovaných s příznaky ILI
[Phylogenetic and molecular analysis of A/H1N1pdm influenza viruses isolated in the epidemic season 2012/2013 from hospitalised patients with -symptoms of influenza-like illness]
Language Czech Country Czech Republic Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
25025668
PII: 49174
- MeSH
- Time Factors MeSH
- Influenza, Human epidemiology virology MeSH
- Epidemics MeSH
- Phylogeny * MeSH
- Hospitalization MeSH
- Humans MeSH
- Oseltamivir pharmacology MeSH
- Drug Resistance, Viral MeSH
- Influenza A Virus, H1N1 Subtype classification drug effects genetics MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic epidemiology MeSH
- Names of Substances
- Oseltamivir MeSH
AIM: To perform phylogenetic and molecular analysis of A/H1N1pdm influenza viruses isolated in the epidemic season 2012/2013 from hospitalised patients with symptoms of influenza-like illness (ILI). MATERIAL AND METHODS: The study set included 34 strains of the A/H1N1pdm influenza virus isolated in the Czech Republic in the epidemic season 2012/2013. The strains were analysed by partial or whole-genome sequencing. The genome segments were compared at the nucleotide and amino acid levels, absolute and percentage sequence identity were determined, and phylogenetic relations were identified. The last steps were the comparison of the H1 molecule with that of the most recent vaccine strain and identification of the genotypic structure and molecular markers linked to the pathogenicity and antiviral resistance. RESULTS: Phylogenetic analysis of the H1 molecule suggested that all 34 A/H1N1pdm isolates from the 2012/2013 season in the Czech Republic should be assigned to H1 group 6 divided into sublineages 6A and 6B. The comparison of the known antigenic regions of the H1 molecule with those in the most recent vaccine strain revealed two stable changes in antigenic regions Sb and Ca1. Furthermore, sporadic mutations were identified in antigenic regions Ca2, Cb, and Sb. Genotyping revealed co-circulation of two related but clearly distiguishable genotypes of A/H1N1pdm. All isolates showed sensitivity to oseltamivir. One strain consisted of two N1 sub-populations, one oseltamivir sensitive and the other oseltamivir resistant, in nearly equimolar proportions. CONCLUSION: All A/H1N1pdm isolates from the epidemic season 2012/2013 in the Czech Republic formed a phenotypically uniform group. At the nucleotide level, the divergence was relatively more pronounced and H1 sublineages and discrete genotypes were possible to identify. H1 molecules were highly identical to those of the vaccine strain A/California/7/2009 (H1N1) which showed that the current vaccine was protective enough. All strains were sensitive to oseltamivir; however, the selection of oseltamivir resistant N1 subpopulations was observed.
