Laboratory diagnosis and genetic characterization analysis of the subtype A3 influenza viruses in Quanzhou
10.3760/cma.j.issn.1009-9158.2011.01.015
- VernacularTitle:泉州市流感疫情实验室检测及H3N2亚型基因特性分析
- Author:
Youxian ZHENG
;
Mingchun CHEN
;
Geng WANG
;
Caiting GONG
;
Jieyi CHEN
;
Jinzhong LIN
- Publication Type:Journal Article
- Keywords:
Influenza,human;
Influenza A virus,H3N2 subtype;
Hemagglutinin glycoproteins,influenza virus;
Base sequence
- From:
Chinese Journal of Laboratory Medicine
2011;34(1):55-57
- CountryChina
- Language:Chinese
-
Abstract:
Objective To obtain the information of the 2009 influenza outbreak and the variations of influenza virus strains in quanzhou, and explore the relationship between the genetic variation of influenza virus and influenza epidemic. Methods During the influenza outbreak in quanzhou,one hundred and ninetyeight throat swabs specimens from the patients with influenza were collected. Viruses were isolated with MDCK cells and identified with serological test, followed by real-time RT-PCR. RNA of four influenza virus strains were extracted, then HA1 gene was amplified by RT-PCR. The purified PCR products were sequenced. The data were analyzed with the software DNAstar megalign. Results Total 98 pieces of H3N2 subtype influenza virus nucleic acid were detected in 198 throat swabs specimens,among which 62 influenza virus strains were identified as subtype influenza A( H3N2 ). The sequencing results of HA1 gene in these positive strains showed that their genetic characterization were more closed to strains A/Ningbo/333/2008 with a nucleotide homology of 98.7%, which was 96.8% as compared with A/Xiamen/70/2004. The amino acids sequences deduced from the nucleotide sequences in HA1 region of the isolated strain had 7 mutant sites compared with A/Brisbane/10/2007 vaccine strain. One variant amino acids were found located in the antigenic determinant sites A( 144 ), two were in the sites B( 158,189 ). Phylogenetic analysis also confirmed the difference in HAl domain. Conclusion The influenza virus strains causing the flu outbreak among some communities of quanzhou in 2009 are subtype influenza A ( H3N2 ), whose genetic characterization and antigenicity were different from the vaccine strain.
