Analysis of the characteristics of hemagglutinin and neuraminidase genes of influenza A/H1N1(09pdm) viruses isolated in Yancheng area in 2014-2017
10.3760/cma.j.issn.1003-9279.2018.05.013
- VernacularTitle: 2014—2017年盐城地区甲型H1N1流感病毒HA、NA基因变异分析
- Author:
Guoqing CHEN
1
;
Chunxiang LI
2
;
Yao WANG
1
;
Feng LI
1
;
Shilin XU
1
;
Changcheng LI
1
;
Rongbiao SHAO
1
Author Information
1. Yancheng Center for Disease Control and Prevention, Yancheng 224001, China
2. Yancheng Maternity and Child Health Care Hospital, Yancheng 224002, China
- Publication Type:Journal Article
- Keywords:
Influenza A/H1N1(09pdm) virus;
RT-PCR;
Hemagglutinin gene;
Neuraminidase gene;
Sequencing
- From:
Chinese Journal of Experimental and Clinical Virology
2018;32(5):510-516
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the genetic characteristics of the hemagglutinin(HA) and neuraminidase(NA) genes of the influenza A/H1N1(09pdm) viruses isolated in the city of Yancheng in 2014-2017.
Methods:The throat swab specimens of patients with influenza-like illness (ILI) from sentinel surveillance hospitals and outbreak sites were detected using the method of real time RT-PCR. The influenza A/H1N1(09pdm) viruses were isolated using MDCK cell culture method in 2014-2017. The strains in 2014-2017 were selected randomly and their sequences of the HA1 and NA genes were amplified through one step RT -PCR method and the PCR products were sequenced. The mutations of genes and acid locus were analyzed and the evolutional trees were generated using bioinformatics software.
Results:The clustering relationships of the respective branches of HA1 and NA genes of seventeen A/H1N1(09pdm) strains isolated in Yancheng area were basically the same and the phylogenetic trees of HA1 and NA genes were respectively clustered into four evolutionary branches. Compared with the vaccine strain A/California/07/2009(H1N1pdm)in the Northern Hemisphere, a total of three antigen epitopes (Ca, Sa, Sb) in HA1 genes of strains in Yancheng area were involved in six antigenic sites (K154R, S162N, K163Q, S185T, L191I, S203T); there were three mutations (D222G/N, G223R, E224K) in the 220 ring and one locus (L191I) in the 190 helix of the receptor binding sites; the two strains (A/Jiangsu-YC/SWL1540/2017, A/Jiangsu-YC/SWL1545/2017) isolated in 2017 increased the 162NQS glycosylation site. Because the strains of the antigen epitopes, receptor binding sites and glycosylation sites in the HA1 genes had a certain degree of variations in Yancheng area in 2014-2017, the protective effects of vaccine strain A/California/07/2009 (H1N1pdm) was limited at the gene level. The two strains (A/Jiangsu-YC/SWL1540/2017 and A/Jiangsu-YC/SWL1545/2017) isolated in 2017 were clustered with vaccine strain A/Michigan/45/2015(H1N1pdm) and had better protective effects. Seventeen A/H1N1(09pdm) strains had no mutations in catalytic residues and drug resistant sites of NA genes, but a part of strains had a certain degree of variations in glycosylation sites of NA genes.
Conclusions:These results indicated the HA1 and NA genes of influenza A/H1N1(09pdm) viruses circulated in Yancheng area in 2014-2017 changed gradually. The accumulation of these mutations would result in antigenic drift of influenza A/H1N1(09pdm) viruses.
