禽流感病毒核蛋白基因的原核表达及其生物学活性分析

禽流感病毒(A v ian in fluenza v irus,A IV)是由A型流感病毒引起的一种禽类的感染或/和疾病综合征[1,2],是被世界动物卫生组织(O IE)确定的I类烈性传染病。该病自1878年在意大利鸡群首次暴发以来,已对养殖业造成了严重的经济损失。近年来,我国各地及世界上许多国家都有禽流感     

抗H9亚型禽流感病毒单克隆抗体的制备及初步鉴定

禽流感(A vian Influenza,AI)是由禽流感病毒(A vian Influenza Virus,A IV)引起的禽的烈性传染病,我国于1992年首次报道有A I存在。2003年12月以来,亚洲10余个国家和地区接连发生禽流感,上千万只鸡病死或被杀,越南和泰国犤2犦还出现了人感染禽流感而死亡的病例。关于禽流感病毒的诊断方法已有大量报道。虽然病毒的分离鉴定是诊断禽流感的一种可靠方法,但由于试验周期长,难以满足对高致病性禽流感快速诊断的需要。因此,建立禽流感快速诊断技术,预防和控制高致病性禽流感的扩散和侵入已成为当务之急。单克隆抗体具有对各个抗原决定簇的…     

禽流感免疫预防的研究进展

禽流感(Avian Influenza,AI)是由正粘病毒科中的A型流感病毒引起的禽类疾病,其中高致病性禽流感(highly pathogenic avian influenza,HPAI)已被世界动物卫生组织(OIE)列为I类烈性传染病.     

禽流感研究进展

最早的禽流感记录是1878年意大利发生鸡群大量死亡的现象,当时被称为鸡瘟;到1955年,科学家证实其病原为甲型流感病毒;此后,这种流行性疾病被更名为禽流感。禽流感是禽流行性感冒(AI的简称,是A型禽流感病毒(AIV)所引起的一种禽类急性传染病。作为被世界动物卫生组织(OIE)定为A类的传染病,AI不仅给世界养禽业造成了巨大的经济损失,而且对人类健康和生命安全构成了严重威胁。从1878年禽流感首发于意大利至今,全球性的禽流感大流行已出现多次。特别是自     

禽流感的诊断与防治

禽流感(AI)是由A型流感病毒引起的发生于各种家禽和野鸟的高度接触性传染病,此病毒有多种血清亚型,其中大部分是没有致病性的,有些是属于低致病性的。根据禽流感病毒致病性和毒力的不同,可以将禽流感分为高致病性禽流感、低致病性禽流感和非致病性禽流感。其中,高致病性禽流感已被世界动物卫生组织列为A类传染病。1病原禽流感的病原为禽流感病毒(AIV),该病毒属正粘病毒科,正粘病毒属,A型流感病毒。AIV除A型外,还有B型、C型。其中B、C两型仅见于人类,而A型对人类和动物都能感染。在AIV表面有两种重要的表面抗原,即血细胞凝集素(HA)…     

商品肉雏鸡H5亚型禽流感母源抗体动态变化规律探讨

禽流感（AI）是由A型流感病毒引起的一种禽类传染病,被世界动物卫生组织（OIE）规定为A类传染病,我国也将其列为一类动物疫病。该病不仅对养禽业造成了严重打击,也对人类的健康和生命安全构成严重威胁。禽流感疫苗研究的使用,对禽流感防控工作起到了重要作用。     

禽流感的免疫与预防

禽流感(Avian Influenza,AI)是由正黏病毒科中的A型流感病毒引起的禽类疾病,其中高致病性禽流感(highly pathogenic avian influenza,HPAI)已被世界动物卫生组织(OIE)列为I类烈性传染病,给全球的养禽生产造成了巨大的经济损失,是养禽     

鸭免疫重组禽流感病毒H5亚型二价灭活疫苗(H5N1,Re-5+ Re-4)后抗体水平分析

禽流感(AI)是由A型流感病毒引起的一种禽类传染病。根据致病性的不同将禽流感分为高致病性禽流感(HPAI)和低致病性禽流感(IPAI),HPAI被世界动物卫生组织(OIE)列为A类传染病,我国     

红细胞浓度对禽流感血凝和血凝抑制试验(HA/HI)结果的影响

高致病性禽流感是由A型禽流行性感冒病毒引起的一种禽类(家禽和野禽)的急性、高度接触性的传染病。高致病性禽流感因其在禽类中传播快、危害大、病死率高,可以直接感染人类,被世界动物卫生组织列为A类动物疫病,我国将其列为一类动物疫病。由于高致病性禽流感对畜牧业和人     

禽流感的消毒预防

禽流感是由A型流感病毒中的任何一种引起的感染综合征。禽流感以其感染过程复杂、传染来源广泛、传播速度快、致病力强、禽类死亡率高(部分毒株)以及感染人类和低等哺乳动物而被世界各国所重视，该病已被列为一类畜禽传染病。近些年来，禽流感对人类的感染力逐渐增强，导致人发病死亡的     

禽流感病毒分子生物学检测技术研究进展

禽流感(avian influenza,AI)是A型流感病毒引起的一种禽类传染病,同时也是一种人和动物之间的高度传染性疾病。近年来,禽流感病毒的分子生物学检测技术发展迅速,文章就此进行了综述。     

H5亚型鸭源流感病毒HA基因序列生物信息学分析

A型流感病毒（AIV）引起的禽类禽流行性感冒（avian influenza,AI）或相关疾病,被国际兽疫局定为甲类传染病。AIV中最容易突变的基因是血凝素（HA）基因,具有亚型和株的特异性,是区分病毒亚型的依据之一。本研究从GenBank中下载了所有209条鸭源H5禽流感病毒HA基因的全序列,利用生物信息学软件构建进化树研究序列的聚类特点;比较不同年份毒株的HA基因的受体结合位点氨基酸,找出受体结合位点氨基酸的变异规律;比较不同年份分离的鸭源H5N1序列的HA1和HA2蛋白的剪切位点,找出各年份毒株的剪切位点的特点;比较不同年份分离序列的潜在糖基化位点,统计各年份潜在糖基化位点的数量以及序列变化。期望找到H5亚型鸭源流感病毒的变异规律和变异方向,为鸭源流感的防控起到积极的作用。     

禽流感诊断技术研究进展

禽流感是严重危害畜牧业和人类健康的一种传染性疾病,多年来在世界上许多国家和地区都发生过此病,危害巨大.世界各国对其进行了大量研究.文章就目前国内外对禽流感病毒血清学和分子生物学诊断技术的研究进展做一综述.     

禽流感疫苗研究进展

近几年禽流感的大范围流行,不仅给养禽业造成了巨大的经济损失,而且由于禽流感可直接感染人并导致死亡,故对人类健康也带来严重的威胁。疫苗免疫仍然是防止禽流感暴发的主要措施,但禽流感病毒变异性强,血清型众多,给疫苗的研究带来极大困难。就目前而言,能在实践上应用的禽流感疫苗主要还是灭活疫苗,这种疫苗具有亚型特异性,但也正是这种特性限制了这种疫苗的发展。随着生物技术的快速发展,其他新型疫苗尤其是基因工程疫苗的研究也取得了一定的进展。使我国应用禽流感疫苗,预防高致病力禽流感的防制策略成为可能。文章就目前禽流感疫苗的研究方面介绍了国内外的一些研究进展。     

禽流感病毒神经氨酸酶的结构及其生物学功能

高致病性禽流感是由禽流感病毒(AIV)引起的一种急性传染病。AIV呈球形,有囊膜。其表面主要有2种糖蛋白,即血凝素和神经氨酸酶。其中神经氨酸酶具有重要功能,其对病毒的释放及病毒在感染细胞周围的扩散能力有很大影响。此外,神经氨酸酶对其周围的血凝素切割能力也有很大影响,从而在一定程度上可以导致病毒致病性的不同。神经氨酸酶是AIV中另一种重要抗原,抗神经氨酸酶的抗体可为机体遭受流感病毒攻击提供一定的保护力。因此,神经氨酸酶对AIV的生物学特性具有重要意义。     

Development and evaluation of a DAS-ELISA for rapid detection of avian influenza viruses

Rapid detection of avian influenza virus (AIV) infection is critical for control of avian influenza (AI) and for reducing the risk of pandemic human influenza. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was developed for this purpose. The method employed a monoclonal antibody (MAb) as the capture antibody and rabbit polyclonal IgG labeled with horseradish peroxidase as the detector antibody, and both antibodies were against type-specific influenza A nucleoprotein (NP). The DAS-ELISA could detect minimally 2.5 ng of influenza viral protein in virus preparations treated with Triton X-100, which is equvilent to 2.5 x 10(2) EID50 virus particles. This DAS-ELISA could detect all 15n AIV subtypes (H1-H15) and did not cross react with other avian pathogens tested. The DAS-ELISA were directly compared with virus isolation (VI) in embryonated chicken eggs, the current standard of influenza virus detection, for 805 chicken samples. The DAS-ELISA results correlated with VI results for 98.6% of these samples, indicating a sensitivity of 97.4% and specificity of 100%. The method was further tested with H5N1 and H9N2 AIV experimentally infected chickens, ducks, and pigeons, as well as field samples obtained from central China in 2005. The DAS-ELISA method has demonstrated application potential as an AIV screening tool and as a supplement for virus isolation in Asia.     

禽流感病毒跨种传播机制的研究进展

禽流感病毒(AIV)是一种重要的人畜共患病病原,严重威胁着畜禽养殖业及人类的公共卫生安全。通常情况下,AIV由于对人唾液酸受体的亲和性较低而不能直接感染人。但自1997年香港报道了首例人感染高致病性H5N1 AIV的事件后,AIV感染人的事件便时有发生。本文从禽流感的危害、AIV的基因组结构及功能、AIV跨种传播的影响因素等方面重点阐述了AIV的跨种传播机制,为AIV的综合防控提供了参考,同时也为抗流感药物的研发提供了理论依据。     

Development of Indirect Enzyme-linked Immunosorbent Assay with Nucleoprotein as Antigen for Detection and Quantification of Antibodies against Avian Influenza Virus

Avian influenza (AI) is a serious infectious disease caused by avian influenza virus (AIV) belonging to type A Orthomyxovirus. In the present study, we developed an indirect enzyme-linked immunosorbent assay (ELISA) employing E. coli-expressed full-length nucleoprotein (NP) of H9N2 avian influenza virus for the detection and quantification of antibodies against AIV nucleoprotein. The NP-ELISA was compared with the AI agar gel propagation (AGP) test, haemagglutination inhibition (HI) test, and IDEXX-FlockChek ELISA using 263 sera. The NP-ELISA was significantly more sensitive than the AGP and HI tests, and showed 96.2% agreement ratio with IDEXX-FlockChek ELISA. With results obtained using the NP-ELISA, an ELISA titre (ET) prediction equation, with which the ELISA titres of a flock or individual chickens can be determined, was derived from a positive/negative (P/N) ratio standard curve. The NP-ELISA enables an alternative rapid serological diagnosis and is suitable for influenza A antibody screening, especially in species that harbour several influenza subtypes.     

Investigation of H7N2 avian influenza outbreaks in two broiler breeder flocks in Pennsylvania, 2001-02

An avian influenza (AI) outbreak occurred in meat-type chickens in central Pennsylvania from December 2001 to January 2002. Two broiler breeder flocks were initially infected almost simultaneously in early December. Avian influenza virus (AIV), H7N2 subtype, was isolated from the two premises in our laboratory. The H7N2 isolates were characterized as a low pathogenic strain at the National Veterinary Services Laboratories based on molecular sequencing of the virus hemagglutinin cleavage site and virus challenge studies in specific-pathogen-free leghorn chickens. However, clinical observations and pathologic findings indicated that this H7N2 virus appeared to be significantly pathogenic in meat-type chickens under field conditions. Follow-up investigation indicated that this H7N2 virus spread rapidly within each flock. Within 7 days of the recognized start of the outbreak, over 90% seroconversion was observed in the birds by the hemagglutination inhibition test. A diagnosis of AI was made within 24 hr of bird submission during this outbreak using a combination of virus detection by a same-day dot-enzyme-linked immunosorbent assay and virus isolation in embryonating chicken eggs. Follow-up investigation revealed that heavy virus shedding (90%-100% of birds shedding AIV) occurred between 4 and 7 days after disease onset, and a few birds (15%) continued to shed virus at 13 days post-disease onset, as detected by virus isolation on tracheal and cloacal swabs. AIV was not detected in or on eggs laid by the breeders during the testing phase of the outbreak. The two flocks were depopulated at 14 days after disease onset, and AIV was not detected on the two premises 23 days after depopulation.     

H10N8亚型禽流感病毒的研究进展

中国于2013年底首次发现H10N8亚型禽流感病毒（AIV）能感染人并致死的病例,而在此之前从未有过关于H10N8亚型病毒能感染人的报道,目前也未在其他国家监测到H10N8亚型AIV感染人的病例。与H7N9亚型AIV相似,H10N8亚型AIV在家禽中致病性很弱,可一旦感染人能表现出很强的致病性。感染了H10N8亚型AIV的患者病情恶化快、死亡率高、对人的健康危害很大,但至今尚无有效的防制手段。目前还不太清楚H10N8亚型AIV是通过何种途径传播给人的,今后H10N8亚型AIV是否会在人群中引发新的疫情暴发是人们普遍关心的问题。文章简要介绍了H10N8亚型AIV的特点及研究现状。