兔出血症病毒胶体金免疫层析试纸条诊断方法的建立及初步应用

为了建立一种快速、简便的兔出血症病毒(RHDV)的检测方法,用胶体金标记纯化的RHDV多克隆抗体,以杆状病毒表达系统表达的重组RHDV VP60蛋白为免疫原制备RHDV的单克隆抗体(McAh,简称单抗)A3C,将RHDV McAb和羊抗兔IgG抗体包被在硝酸纤维素膜上,分别作为检测线和质控线,经条件优化研制成RHDV免疫胶体金试纸条.该试纸条可以检出红细胞凝集试验(HA)效价为1:10的RHDV悬液,即HA检测为阴性的样品,该试纸条检测为阳性,其敏感性高于HA;特异性试验结果显示,该试纸条不与家兔其他常见病菌发生交叉反应.应用该试纸条对127份疑似兔出血症家兔肝脏样品进行初步检测,同时用HA做平行试验,阳性符合率为100％.因此,该试纸条是一种快速、灵敏、特异的兔出血症病毒检测方法,为兔出血症的现场诊断提供了有效的方法,显示出很好的临床应用前景.     

Dot-ELISA与IHA方法诊断肝片形吸虫病的比较

用斑点酶联免疫吸附试验(Dot-ELISA)对200份经粪检和间接血凝试验(IHA)血检的血清样品进行肝片形吸虫感染的检测,同时在屠宰场现场对50份样品进行检测,并与剖检相比较。结果显示Dot-ELISA与IHA法相比,阳性符合率较低(84.21%),阴性符合率高(95.58%),总符合率94.50%;Dot-ELISA与粪检结果相比,阳性符合率(94.74%)明显高于IHA法;与剖检法比较,Dot-ELISA对屠宰场现场样品的检出率和阳性符合率均为100%。结论:Dot-ELISA较IHA法敏感性高、特异性强,适宜用作牛、羊肝片形吸虫感染的现场检测。     

兔病毒性出血症检测方法的研究进展

兔病毒性出血症(RHD)又称出血性败血症,俗称兔瘟,是由兔病毒性出血症病毒(RHDV)引起的一种发病急、死亡率高的传染病。为了更好地加强病毒的检测与防控,需要更精确、方便的检测方法以满足科研和基层的不同需要,文章对近年来RHDV检测方法的研究进展进行了综述,主要包括酶联免疫吸附试验(ELISA)、荧光定量PCR、环介导等温扩增技术(LAMP)和胶体金免疫层析(GICA)等,以期为RHDV的防控及诊断提供参考。     

兔病毒性出血症病毒重组蛋白VP60间接ELISA抗体检测方法的建立与应用

为建立一种快速的兔病毒性出血症病毒抗体检测方法,本研究以原核表达的重组VP60蛋白作为诊断抗原,建立了检测兔病毒性出血症病毒抗体的VP60-ELISA诊断方法。该方法检测3种常见兔病(兔轮状病毒、仙台病毒和魏氏梭菌)的阳性血清均为阴性;检测灵敏度为1:12800;批内、批间重复性试验的变异系数分别小于4.9%和6.9%。本研究建立的RHDV VP60-ELISA检测方法具有良好的特异性、敏感性和重复性,为RHDV的抗体检测及流行病学调查等快速诊断提供了一种技术手段。     

鉴别RHDV与RHDV2荧光定量RT-PCR检测方法的建立与应用

为建立一种敏感、特异、快速、操作简便、易于判定的鉴别检测兔出血症病毒(RHDV)与兔出血症病毒2型(RHDV2)荧光定量RT-PCR检测方法,本研究选择RHDV与RHDV2 VP60基因序列高度同源的保守区域设计了 3对引物,经荧光定量PCR扩增比较,筛选出1对引物,对各反应条件进行优化,建立了 RHDV与RHDV2荧...     

兔出血症病毒和巴氏杆菌双重PCR检测方法的建立及应用

参照GenBank公布的兔出血症病毒(RHDV)VP60、巴氏杆菌kmt基因序列,设计两对引物,分别用于扩增RHDV的VP60和巴氏杆菌kmt基因的目的片段。通过正交试验,对反应各组分浓度与组合、反应退火温度及反应参数进行优化,最后建立了RHDV、巴氏杆菌双重PCR检测方法并进行临床应用。结果显示:本试验建立的双重PCR检测方法能够特异性地检测RHDV及巴氏杆菌,最低核酸检出限分别达到70 pg和62pg。检测兔源大肠杆菌、葡萄球菌和链球菌,结果均为阴性。用本方法对临床送检的104份病料进行检测,结果检出RHDV与巴氏杆菌混合感染1份,巴氏杆菌单独感染10份,双重PCR检测结果与临床病原分离结果完全一致。表明本试验建立的兔出血症病毒和巴氏杆菌双重PCR检测方法具有良好的临床应用价值。     

Dot-ELISA法检测致病性嗜水气单胞菌

在鱼类致病性气单胞菌诊断试剂盒的基础上,用斑点酶联免疫吸附试验(Dot-ELISA)检测致病性嗜水气单胞菌(Aeromonas hydrophila,Ah)胞外蛋白酶ECPase54,同时用脱脂奶平板、PCR特异性扩增气溶素基因aer和16S rRNA基因检测72株气单胞菌分离株.结果显示致病性嗜水气单胞菌检测阳性率分别如下:Dot-ELISA法90.3％(65/72)、脱脂奶平板法75％(54/72)、aer基因PCR法94.4％(68/72)、16S rRNA PCR法81.9％(59/72),Dot-ELISA与其他3种方法的符合率分别为79.2％(57/72)、91.6％(66/72)、81.9％(59/72).在ECPase54兔抗血清制备后的2、4、6、12、18个月,用Dot-ELISA检测72株分离株,检测结果重复性好.结果表明Dot-ELISA法敏感、特异、实用,可用于鱼类致病性Ah的临床诊断.     

TaqMan MGB探针实时检测兔病毒性出血症病毒

应用荧光定量PCR技术,根据兔病毒性出血症病毒的保守基因VP60设计了1对引物和1段Taqman MGB探针,建立了用于检测兔病毒性出血症病毒的实时荧光定量RT-PCR方法。试验中能够检出的RHDV VP60基因质粒拷贝数达103数量级,能够检测到RHDV病毒核酸最低量可以达到5 pg,未检出其他病原的RNA。试验结果表明,建立的TaqMan MGB探针实时荧光定量RT-PCR方法的特异性、敏感性、重复性均达到试验设计要求,能快速检测临床样品中的兔病毒性出血症病毒,适合于兔各脏器及肌肉组织中兔病毒性出血症病毒的快速诊断和检测。     

三峡库区兔病毒性出血症流行情况调查

为了调查三峡库区兔病毒性出血症(RHD)的流行情况,在三峡库区的开县、石柱县、渝北区等养兔示范县调查20个兔场,采集疑似RHD病料32份。采用血凝试验(HA)、血凝抑制试验(HI)对病料进行检测。结果表明HA试验检测到4株兔病毒性出血症病毒(RHDV),阳性率为12.5%,HA效价为8~12 lb;这4株RHDV血凝性都能被RHDV疫苗毒株(AV33)的抗血清抑制。在RHD疫苗普免的情况下,目前库区虽然没有RHD的大流行,但仍然存在RHD的散发,应引起兽医防疫部门和养兔场的高度重视。     

基因重组抗原酶联免疫法检测兔出血症病毒抗体及其标准化

以重组兔出血症病毒(RHDV)VP60蛋白为抗原，建立了RHDV抗体间接ELISA检测方法。优化的试验反应务件为：重组VP60的包被质量浓度为1．0mg／L，用10％牛血清封闭，以大肠杆菌提取物稀释被检血清以消除非特异性反应。将所建立的ELISA与现行血凝抑制(HI)试验比较发现，不同免疫状态的兔血清的RHDV ELISA抗体与HI抗体均呈正相关。对11个RHD免疫兔场1130份血清样品的抗体检测表明，各免疫兔群血清RHDV抗体水平不完全一致，D值在1．09～1．76之间，显著高于非免疫兔(0．05)及SPF兔(0．02)，低于高免兔(2．34)。在此基础上，研制了RHDV抗体酶联免疫检测试剂盒，测定了其主要指标，制定了各成分的质量控制标准，为兔群进行免疫学监测及评价疫苗的免疫效果提供了便利。     

兔出血症-巴氏杆菌病铝胶二联灭活苗的研制

筛选了具有良好免疫原性的兔瘟强毒株GMH881和兔巴氏杆菌C51-17株,研制出了兔出血症-巴氏杆菌二联铝胶灭活苗,对疫苗进行了免疫剂量、免疫产生期、兔出血症抗体测定、免疫保护期、保存期等试验;确定出二联铝胶苗免疫剂量1.0 mL;二联铝胶苗在免疫后7 d对兔病毒性出血症强毒的保护率达到100%,二联苗免疫后10～14 d对兔巴氏杆菌的保护率均达到75%以上;二联铝胶苗的兔病毒出血症抗体测定结果表明：二联铝胶苗免疫家兔后7 d,HI抗体均可达25.0,15 d明显上升,二联苗HI效价60～90 d达到最高峰,最高可达210,二联苗在120～180 d仍可维持在27.0～29.5水平。二联铝胶苗分别在免疫后4个月、6个月用兔出血症强毒攻击均产生100%保护,在6个月用2个MLD的兔巴氏杆菌攻击保护率可达70%以上,二联铝胶苗4～8℃条件下保护期暂定为1年,25℃条件下暂定为半年。     

家兔病毒性出血症病毒(RHDV)的研究进展

兔病毒性出血症(RHD)是一种导致家兔急性、烈性、高度致死性的传染病,发病率和死亡率较高,是严重威胁家兔产业发展的传染病之一。本文综述RHDV的病原学、检测方法、遗传变异等方面的研究进展,同时对RHDV未来研究方面做一展望,旨在为深入研究RHDV提供一定参考和信息。     

散发性兔病毒性出血症的观察

通过对云南发病较多的12个兔场进行流行病学调查、临床症状及剖检变化观察、细菌培养、HA和HI试验,结果发现：兔病毒性出血症（RHD）可以在免疫过的兔场呈散发性流行;RHD散发性流行时,还会有其他疾病的存在：观察到散发性RHD的主要特点是最急性病例少见,病变出现率低,病变轻微,病程比文献报道的长。结果显示．散发性RHD发生的主要原因是兔群中存在免疫空白和免疫力低下的个体。建议开展RHD免疫程序与抗体水平,仔兔、幼兔母源抗体的消长规律,不同母源抗体水平的免疫效果观察等研究,建立更科学的免疫程序．并根据母源抗体监测结果确定首免日龄。     

The new French 2010 Rabbit Hemorrhagic Disease Virus causes an RHD-like disease in the Sardinian Cape hare (Lepus capensis mediterraneus)

Lagovirus is an emerging genus of Caliciviridae, which includes the Rabbit Hemorrhagic Disease Virus (RHDV) of rabbits and the European brown hare syndrome virus (EBHSV) of hares that cause lethal hepatitis. In 2010, a new RHDV related virus (RHDV2) with a unique genetic and antigenic profile and lower virulence was identified in France in rabbits. Here we report the identification of RHDV2 as the cause in Sardinia of several outbreaks of acute hepatitis in rabbits and Cape hare (Lepus capensis mediterraneus). This is the first account of a lagovirus that causes fatal hepatitis in both rabbits and hares.     

兔病毒性出血症基因工程苗研究概况

由于兔病毒性出血症 (RHD)组织灭活苗涉及的成本、生物安全及动物福利等问题 ,国内外学者正致力于 RHD新型疫苗的研制和开发。以 VP60表达为基础的亚单位疫苗经历了最初的原核、真核表达 ,目前正寻求在转基因植物中进行表达 ,以期获得大量、低成本的口服疫苗 ;而以牛痘、金丝雀痘病毒、黏液瘤病毒等作载体的重组活载体苗 ,无疑使 RHD疫苗正在向更安全、实用及对家兔、野兔均有保护作用方向发展 ,具有很大的发展潜力和前景。国外学者在RHD基因工程苗方面研究较为广泛和深入 ,而国内尚未有此方面报道     

A simple and rapid method for isolation of caliciviruses from liver of infected rabbits

Rabbit Haemorrhagic Disease Virus (RHDV), a member of the Caliciviridae family, is the etiologic agent of Rabbit Haemorrhagic Disease (RHD); this viral disease is highly contagious and kills more than 90% of infected adult rabbits. Research on experimental calicivirus infection uses inocula obtained from livers of rabbits dying from calicivirus infection. This implies that caliciviruses have to be purified from liver homogenates. Current methods to isolate caliciviruses from rabbit livers are time consuming. We propose here a new procedure for fast purification of rabbit caliciviruses from liver homogenates that uses centrifugation through an iodixanol gradient. This method offers in approximately 2 h a sample with a high degree of calicivirus purity, as shown by its biochemical and immunocytochemistry analysis, which is also able to kill adult rabbits from RHD within 48 h of inoculation.     

兔瘟强毒株的筛选和血清型鉴定——兔瘟H9组织灭活疫苗的研制

从安哥拉兔病死兔的肝脏中分离到一株病毒,经血凝试验、血凝抑制试验和动物交叉免疫保护试验,确定为兔瘟病毒(称RHDV-H)。     

An isolated epizootic of hemorrhagic-like fever in cats caused by a novel and highly virulent strain of feline calicivirus

An isolated epizootic of a highly fatal feline calicivirus (FCV) infection, manifested in its severest form by a systemic hemorrhagic-like fever, occurred over a 1-month period among six cats owned by two different employees and a client of a private veterinary practice. The infection may have started with an unowned shelter kitten that was hospitalized during this same period for a severe atypical upper respiratory infection. The causative agent was isolated from blood and nasal swabs from two cats; the electron microscopic appearance was typical for FCV and capsid gene sequencing showed it to be genetically similar to other less pathogenic field strains. An identical disease syndrome was recreated in laboratory cats through oral inoculation with tissue culture grown virus. During the course of transmission studies in experimental cats, the agent was inadvertently spread by caretakers to an adjoining room containing a group of four normal adult cats. One of the four older cats was found dead and a second was moribund within 48-72h in spite of symptomatic treatment; lesions in these animals were similar to those of the field cats but with the added feature of severe pancreatitis. The mortality in field cats, deliberately infected laboratory cats, and inadvertently infected laboratory cats ranged from 33-50%. This new isolate of calicivirus, named FCV-Ari, was neutralized at negligible to low titer by antiserum against the universal FCV-F9 vaccine strain. Cats orally immunized with FCV-F9, and then challenge-exposed shortly thereafter with FCV-Ari, developed a milder self-limiting form of disease, indicating partial protection. However, all of the field cats, including the three that died, had been previously immunized with parenteral FCV-F9 vaccine. FCV-Ari caused a disease that was reminiscent of Rabbit Hemorrhagic Disease, a highly fatal calicivirus infection of older rabbits.     

Multi-event capture–recapture modeling of host–pathogen dynamics among European rabbit populations exposed to myxoma and Rabbit Hemorrhagic Disease Viruses: common and heterogeneous patterns

Host–pathogen epidemiological processes are often unclear due both to their complexity and over-simplistic approaches used to quantify them. We applied a multi-event capture–recapture procedure on two years of data from three rabbit populations to test hypotheses about the effects on survival of, and the dynamics of host immunity to, both myxoma virus and Rabbit Hemorrhagic Disease Virus (MV and RHDV). Although the populations shared the same climatic and management conditions, MV and RHDV dynamics varied greatly among them; MV and RHDV seroprevalences were positively related to density in one population, but RHDV seroprevalence was negatively related to density in another. In addition, (i) juvenile survival was most often negatively related to seropositivity, (ii) RHDV seropositives never had considerably higher survival, and (iii) seroconversion to seropositivity was more likely than the reverse. We suggest seropositivity affects survival depending on trade-offs among antibody protection, immunosuppression and virus lethality. Negative effects of seropositivity might be greater on juveniles due to their immature immune system. Also, while RHDV directly affects survival through the hemorrhagic syndrome, MV lack of direct lethal effects means that interactions influencing survival are likely to be more complex. Multi-event modeling allowed us to quantify patterns of host–pathogen dynamics otherwise difficult to discern. Such an approach offers a promising tool to shed light on causative mechanisms.