Evolutionary analysis of neuraminidase gene of novel influenza virus A/H1N1 in 2009 pandemic in Guangdong Province / 中华传染病杂志

ABSTRACT

Objective To analyze the genetic characterization(evolution, antigenicity, enzyme activity sites and glycosylation sites)of the neuraminidase(NA)gene of the novel influenza virus A/H1N1 in 2009 pandemic in Guangdong Province. Methods The viral RNA was extracted from 69 isolates of influenza virus A/H1N1 from patients in 2009 pandemic in Guangdong Province. NA gene fragments were amplified by reverse transcription polymerase chain reaction (RT-PCR) and sequenced. The other 52 NA gene sequences of influenza virus A in different years and different regions were retrieved from GenBank. The analysis of evolution and amino acid sequences were analyzed by MEGA 4.0 software. Results The homology of 2009 novel H1N1 influenza viruses in Guangdong and avian H5N1 influenza virus strains was high(＞85 % ). The amino acid distributions of potential antigenic sites were identical. The enzyme activity sites of NA genes of all virus strains were strictly conserved, which had eight glycosylation sites. But there were amino acid substitutions in 5 glycosylation sites, while it was identical with the 2001 avian H5N1 influenza virus. Conclusion The NA genes of 2009 novel H1N1 influenza viruses in Guangdong are high homologous with avian H5N1 influenza virus and the viral specific binding sites of neuraminidase inhibitor are not changed.