[Genetic characterization of haemagglutinin of novel H1N1 influenza viruses in Suzhou City].

OBJECTIVE

To investigate the genetic variation and molecular characteristics of HA gene of influenza A (H1N1) virus isolated in Suzhou during from2009 to 2011.

METHODS

Viral RNA of 5 Suzhou isolates was isolated and their HA gene were amplified and sequenced by the primers and protocol recommended by WHO, and the sequences together with other sequences downloaded from GenBank were analyzed by several bioinformatics software.

RESULTS

Compared with vaccine strain, the average homogeneity of nucleotide and amino acids of 5 Suzhou isolates were between 98.8-99.4% and 98.8-99.4% respectively. All of the 5 strains have 1 amino acids replacement in Sb region and 2 strains have 2 amino acids replacement in Ca region. Strains from and outside Suzhou both showed a trend of clustering by collection year.

CONCLUSION

The Suzhou strains are still in stable condition although 1-2 amino acids replacement had happened in antigenic sites.