H9N2亚型禽流感病毒血凝素和神经氨酸酶基因的遗传分析

Genetic analysis of the hemagglutinin(HA)and neuraminidase(NA)genes of H9N2 influenza viruses isolated from China's Mainland

H9N2亚型禽流感病毒自1994年在中国首次发现以来,一直在家禽中流行,其导致的产蛋下降和发病死亡给养禽业发展带来严重危害。以前的研究发现中国的H9N2亚型禽流感病毒在进化过程中形成多个基因型,其表面抗原蛋白血凝素基因(HA)可被划分为以A/chicken/Beijing/1/94、A/quail/Hong Kong/G1/97(G1)和A/chicken/Heilongjiang/35/01等为代表的3个亚群,神经氨酸酶基因(NA)可被划分为以A/chicken/Beijing/1/94、A/quail/Hong Kong/G1/97(G1)和A/chicken/Hong Kong/G9/97(G9)等为代表的3个亚群。其中类G1病毒的HA基因只在香港分离株中出现。本研究对我国2003年～2004年从禽类中分离的H9N2亚型禽流感病毒血凝素(HA)和神经氨酸酶(NA)基因进行测定和遗传演化分析,结果表明其中11株病毒的HA基因属于CK/BJ/1/94群系,NA基因属于CK/BJ/1/94或DK/HK/G9/97群系,并首次发现两株病毒含有类G1病毒HA和NA基因,而且这些类G1病毒具有不同的抗原性以及人流感病毒的受体结合位点。本研究结果提示应对H9N2病毒的防治及其公共卫生意义予以高度重视。

The H9N2 subtype of avian influenza viruses have widely circulated in China's Mainland since 1994. Previous studies revealed that the H9N2 viruses in China's Mainland formed multiple genotypes. The surface protein hemagglutinin （HA） gene could be divided into three sub-lineages represented by A/chicken/Beijing/1/94 （B J/94）, A/quail/Hong Kong/G1/97（G1） and A/chicken/ Heilongjiang/35/01, and the neuraminidase （NA） gene could be divided into three sub-lineages represented by A/chicken/ Beijing/1/94 （BJ/94）, A/quail/Hong Kong/G1/97 （G1） and A/chicken/Hong Kong/G9/97 （G9）. In the present study, we analyzed the HA and NA genes of 13 H9N2 viruses that isolated from China's Mainland during 2003-2004. The results showed that 11 of 13 viruses beared the BJ/94-1ike HA genes and B J/94 or G9-1ike NA genes, and the other two viruses isolated from Guangdong province contained Gl-like HA and NA genes. The detection of G1-like virus, which have different antigenic properties and human influenza virus like amino acids at the receptor binding sites of HA gene, highlighted the need to the control of H9N2 viruses in both poultry and humans as well.