广西H9亚型禽流感病毒全基因组序列分析及疫苗候选株的筛选

发布时间：2018-03-13 18:31

本文选题：H9亚型禽流感病毒　切入点：分离鉴定　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：H9亚型禽流感是危害养禽业的重要疾病,在全世界均有分布,在我国主要为H9N2亚型。该病毒能够引起鸡群呼吸道、生殖系统疾病,造成生长缓慢、产蛋下降等,严重制约我国养禽业的发展。并且,H9N2亚型禽流感病毒具有直接感染人的特性,其公共卫生意义重大。为了掌握广西地区H9亚型禽流感病毒的流行以及遗传变异情况,本研究对广西地区2011-2014年不同家禽和野禽进行H9亚型禽流感病毒的病原学监测,建立了H9和N2亚型禽流感二重RT-PCR的检测方法,广西株进行了分离、纯化、鉴定、全基因测序和遗传进化分析。本研究共分离并纯化了17株H9亚型禽流感病毒,其生物学特性、核苷酸和氨基酸序列都符合低致病禽流感病毒特点。其中有16个毒株具有禽型和人型两种受体亲和特性。所有分离株的HA基因与疫苗株均处于不同的遗传进化分支。17个分离株的8个基因片段大多来源不同,存在不同程度的基因重组,经分析共有4种重组模式。为了评价商品化疫苗对变异毒株的免疫保护效力并筛选出免疫效力较好的H9亚型禽流感灭活疫苗候选毒株,从本研究从本实验室分离得到的39个2000-2014年H9亚型禽流感毒株中,依据进化分支的不同选择了10个代表毒株与商品化疫苗SS株进行抗原差异性分析,并依据抗原相关值从中挑选出4个分离株制成灭活油乳疫苗与商品化疫苗SS株进行交叉保护试验,证实了商品化疫苗SS株对广西变异株保护效果不理想,而A/Chicken/Guangxi/CX/2013 (H9N2)株灭活疫苗能够使鸡群产生较高的抗体水平,可以抵御广西地区大部分H9亚型禽流感流行株的攻击,可以选择作为H9亚型禽流感灭活疫苗候选株。
[Abstract]:H9 subtype avian influenza is an important disease that harms poultry industry and is distributed all over the world. It is mainly H9N2 subtype in China. This virus can cause respiratory tract disease, reproductive system disease, slow growth and egg production decline, etc. In order to understand the prevalence and genetic variation of H9 subtype avian influenza virus in Guangxi, it is of great public health significance. In this study, the pathogens of H9 subtype avian influenza virus in different poultry and wild birds in Guangxi region from 2011 to 2014 were monitored, and the detection method of double RT-PCR of H9 and N2 subtype avian influenza was established. Guangxi strain was isolated, purified and identified. In this study, 17 strains of H9 subtype avian influenza virus were isolated and purified. The nucleotide and amino acid sequences were in accordance with the characteristics of low pathogenic avian influenza virus. Sixteen of them had avian and human receptor affinity. HA gene of all isolates and vaccine strains were in different genetic evolution. Most of the 8 gene fragments from 17 isolates were from different sources. In order to evaluate the immune protection of commercial vaccines against variant strains and to screen out candidate strains of inactivated H9 subtype avian influenza vaccine with better immune efficacy, there are four recombinant models for different degree of gene recombination. From 39 strains of H9 subtype avian influenza virus isolated from our laboratory from 2000 to 2014, 10 representative strains and SS strain of commercial vaccine were selected according to the evolution branch to analyze the antigenic difference between H9 subtype avian influenza virus strains and commercial vaccine SS strain. According to the correlation value of antigen, four strains of inactivated oil milk vaccine and commercial vaccine SS strain were selected for cross protection test, which proved that the protective effect of commercial vaccine SS strain on Guangxi variant strain was not ideal. The inactivated vaccine of A- Chickenr / Guangxi / CX / 2013 H9N2 strain can make chickens produce higher antibody level, and can resist the attack of most H9 subtype avian influenza epidemic strains in Guangxi, and can be selected as a candidate for inactivated vaccine of H9 subtype avian influenza.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S852.65

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