Genetic variation of the hemagglutinin and neuraminidase of influenza B viruses isolated in Ningbo during 2010-2012.

Feng-jiao HU; Yong-dong LI; Su-li JIAO; Shu ZHANG

Return

Genetic variation of the hemagglutinin and neuraminidase of influenza B viruses isolated in Ningbo during 2010-2012.

Author: Feng-jiao HU ¹ ; Yong-dong LI ² ; Su-li JIAO ¹ ; Shu ZHANG ¹
Author Information

1. Municipal Key Laboratory of Virology, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China.
2. Municipal Key Laboratory of Virology, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China. Email: liyd@nbcdc.org.cn.
Publication Type:Journal Article
MeSH: China; epidemiology; Genetic Variation; Hemagglutinin Glycoproteins, Influenza Virus; genetics; Humans; Influenza B virus; classification; genetics; isolation & purification; Influenza, Human; epidemiology; virology; Neuraminidase; genetics; Phylogeny; RNA, Viral
From: Chinese Journal of Preventive Medicine 2013;47(12):1100-1104
CountryChina
Language:Chinese
Abstract:
OBJECTIVETo investigate the epidemiological characteristics of influenza B viruses and explore the genetic evolution characteristics of the hemagglutinin(HA) and neuraminidase(NA) genes of local isolated strains in Ningbo, Southeast China, during 2010 to 2012.
METHODSRespiratory specimens from 3440 cases of patients with influenza-like illness(ILI) during 2010 to 2012 were collected in for virus isolation. And the 628 sera samples were collected in 2010 from the healthy community population to detect the HI antibody level against the local isolated virus.For phylogenetic analysis, the fragments of HA and NA genes were amplified and sequenced from strains isolated in different years. The association between evolution of HA and epidemiological characteristics were analyzed.
RESULTSA total of 109 strains of influenza B virus were isolated, including 102 (93.6%) Victoria-lineage strains and 7 (6.4%) Yamagata-lineage strains. Positive rates of HI antibody against Victoria-lineage strains and Yamagata-lineage strains were 51.1% (321) and 47.8% (300), respectively (χ(2) = 1.405, P > 0.05) among the 628 sera samples. The phylogenetic analysis showed that all HA fragments of isolated strains clustered the same branch with Malaysia/2506/2004 while the NA genes formed different branches. Compared with Brisbane/60/2008 strain, there were 1 to 5 Amino acid mutations in HA domain, and more mutations were detected in NA domain, ranged from 6 to 16 sites. The genetic evolution of NA in Victoria-lineage strains were faster compared with HA.
CONCLUSIONThe genetic evolution rates of NA genes were faster than that of HA genes in the local circulated Victoria-lineage viruses during 2010 to 2012;The comprehensive analysis of HA and NA fragments were more reliable and sensitive on surveillance of genetic evolution of influenza B viruses.