H9N2亚型禽流感病毒血凝素基因的遗传变异

GENETIC MUTATIONS OF THE HEMAGGLUTININ GENES OF H9N2 SUBTYPE AVIAN INFLUENZA VIRUSES

连续3年对某鸡场禽流感感染鸡群进行跟踪监测,对使用疫苗前与使用疫苗后不同时段分离的H9N2亚型禽流感病毒的血凝素(HA)基因进行全序列分析,研究其H9N2亚型禽流感病毒在同亚型灭活疫苗的选择压力下的遗传变异。结果表明:在使用第1次分离的病毒株制备的疫苗后8个月分离该病毒株,其HA基因仅有1个氨基酸发生变异;继续使用该疫苗第2年分离的该病毒株,其HA基因有20个氨基酸发生变异。

In order to explore genetic mutations of hemagglutinin (HA) genes of H9N2 subtype avian influenza viruses (AIVs) under selective pressure of vaccination, infection in chicken flocks on a farm was monitored in three years and H9N2 subtype viruses were isolated either before or after vaccination procedure was introduced. Complete sequence analysis of HA genes of these isolates showed that HA gene of the isolate, which was isolated 8 months after vaccination by vaccine from the first isolate, had only one amino acid different from that of the vaccine strain. But greater changes were seen in the HA genes of the virus of the following second year after vaccination, with 20 amino acids different from that of the vaccine strain.