Full text loading...
Prior to the introduction of the 2009 pandemic H1N1 virus from humans into pigs, four phylogenetic clusters (α-, β-, γ- and δ) of the haemagglutinin (HA) gene from H1 influenza viruses could be found in US swine. Information regarding the antigenic relatedness of the H1 viruses was lacking due to the dynamic and variable nature of swine lineage H1. We characterized 12 H1 isolates from 2008 by using 454 genome-sequencing technology and phylogenetic analysis of all eight gene segments and by serological cross-reactivity in the haemagglutination inhibition (HI) assay. Genetic diversity was demonstrated in all gene segments, but most notably in the HA gene. The gene segments from the 2009 pandemic H1N1 formed clusters separate from North American swine lineage viruses, suggesting progenitors of the pandemic virus were not present in US pigs immediately prior to 2009. Serological cross-reactivity paired with antigenic cartography demonstrated that the viruses in the different phylogenetic clusters are also antigenically divergent.
Article metrics loading...
Full text loading...
References
Data & Media loading...
Supplements
Journal of General Virology vol. 92 , part 4, pp. 919 - 930
Supplementary Table S1a. Reciprocal HI titres for individual serum samples are reported for 24 different US swine influenza viruses.
Supplementary Table S1b. HI titres for individual serum samples.
Supplementary Table S2a. The ratio between homologous and heterologous reciprocal HI titres for individual serum samples are reported for 24 different US H1 swine influenza viruses.
Supplementary Table S2a. Fold-reduction compared to homologous HI titre.
Supplementary Table S3. Reciprocal HI titres for individual serum samples are reported for three 2009 pandemic H1N1 isolates. [Single PDF file](118 KB)