基于pegB基因的鸡白痢沙门氏菌、鸡伤寒沙门氏菌分子鉴别方法的建立

为建立一种能快速、准确、简便区分鸡白痢沙门氏菌和鸡伤寒沙门氏菌的方法，研究通过对鸡白痢沙门氏菌和鸡伤寒沙门氏菌pegB序列进行分析，发现存在3个单核苷酸多态性位点，基于此建立了一种特异性PCR方法用于鉴别鸡白痢沙门氏菌和鸡伤寒沙门氏菌。结果显示，该方法特异性强、耗时短，检测限为10.14 pg/反应。临床样品检测表明，该方法不仅具有良好的特异性，且操作比传统方法更为简便。该方法的建立为准确区分鸡白痢沙门氏菌和鸡伤寒沙门氏菌提供了实用技术，将在分子检测中发挥重要作用。     

不同病毒在SPF鸡胚与普通鸡胚繁殖性能的比较

利用HI和AGP方法检测普通种蛋中ND和IBD的卵黄抗体水平，利用HA和EID50检测方法比较多种病毒(如NDV、IBV、IBDV及AEV)在SPF鸡胚与普通鸡胚上繁殖性能的差异。研究结果表明：普通种蛋中ND及IBD的卵黄抗体水平普遍较高，在SPF鸡胚上新城疫La Sota病毒繁殖量是普通鸡胚的5～20倍，尿囊液血凝效价平均高2.0～2.5滴度。MA5毒株在SPF胚病毒液EID50为普通鸡胚的10倍以上，且每次检测的结果比较接近。IBDV、AEV等病毒在普通鸡胚上几乎不能增殖。     

笼养蛋用鸡血清降钙素水平的检测

对北京某大型蛋用鸡场产蛋高峰期及高峰期后（27、39和51周龄）的临床正常海兰褐色蛋鸡和瘫痪鸡血清的降钙素（CT）水平进行检测，并对瘫痪鸡进行病理剖检和X光检测。结果，产蛋高峰期时，笼养蛋用鸡血清CT水平先上升，然后逐渐下降，瘫痪鸡血清CT水平最低，瘫痪鸡胫骨和跖骨骨密度明显疏松，髓腔变宽，骨髓减少。     

卵黄平板凝集试验检测鸡白痢抗体的研究

卵黄平板凝集试验检测鸡白痢抗体的研究臧为民，王川庆（河南农业大学，郑州４５０００２）鸡白痢以往检疫和监测主要依靠全血平板凝集反应和血清平板凝集反应，这两种方法虽然简便、快速，但由于需要抓鸡采血，为了克服上述缺点，作者用卵黄代替全血和血清进行平板凝集反...     

鸡星状病毒、禽肾炎病毒和鸡传染性支气管炎病毒多重PCR检测方法的建立

为有效确定引起鸡痛风的病原，本试验建立了同时检测鸡星状病毒(CAstV)、禽肾炎病毒(ANV)和鸡传染性支气管炎病毒(IBV)的多重PCR方法。针对IBV的N基因、CAstV和ANV的ORF-1b基因分别设计了3对特异性引物，通过优化退火温度等反应条件建立了多重PCR检测方法，并评估了该方法的特异性和敏感性，而后对临床痛风样本进行了检测。结果显示，多重PCR方法对3种病毒扩增产物的大小分别为1 600 bp(IBV)、794 bp(ANV)和350 bp(CAstV);该多重PCR检测禽马立克氏病毒、血清4型禽腺病毒、减蛋综合征病毒和J亚型禽白血病病毒均为阴性；病毒最低检测限IBV为1.96×10~2 copies/μL,ANV为2.10×10~2 copies/μL,CAstV为1.33×10~5copies/μL;多重PCR对临床病料的检测结果与单项PCR的检测结果一致。结果表明，本试验建立的多重PCR检测方法具有较好的特异性、敏感性和可靠性，为临床鸡痛风的诊断提供了准确、有效的技术手段。     

酶标单抗阻断ELISA检测鸡白痢和鸡伤寒抗体

以辣根过氧化物酶标记的沙门氏菌O9单抗3-47-0与包被的鸡白痢沙门氏菌脂多糖抗原建立了一种抗体阻断EL ISA以检测鸡白痢和鸡伤寒沙门氏菌感染。该方法基于待检血清样品抑制酶标单抗与脂多糖的结合,以检测鸡白痢和鸡伤寒特异性抗体。对72份已知鸡白痢阳性血清(抑制率为(98.5±4.0)%)、54份已知鸡白痢阴性血清(抑制率为(15.3±8.0)%)、42份SPF鸡血清(抑制率为(0.8±7.2)%)检测的结果表明,该方法具有很强的区分能力。在人工感染试验中,从第2周开始,该方法能从全部鸡只中检测到特异性抗体,比全血玻板凝集试验(PAT)早1周时间。对344份种鸡血清的检测结果表明,单抗阻断EL ISA比PAT特异性好、敏感性高。另外,该方法也能检测出与鸡白痢和鸡伤寒沙门氏菌有共同抗原的沙门氏菌感染产生的抗体。     

DIG核酸探针检测病鸡羽髓MDV的研究

拔取病鸡含羽髓的羽毛，用免疫琼扩试验检测，检出率为８０％；将病鸡髓经超声波处理、ＳＤＳ和蛋白酶Ｋ裂解、经酚和氯仿抽提后，用乙醇沉淀病毒核酸，用我们研制的以Ｄｉｇｏｘｉｇｅｎｉｎ标记的ＭＤＶ核酸探针检测，检出率为１００％，结果表明，核酸探针是检测ＭＤＶ灵敏特异的方法。     

脾脏转移因子对粤黄鸡免疫机能的影响

１２０只１日龄雌性粤黄鸡随机分为四组，每周三个实验组胸肌注射０．５ｍｌ不同浓度的鸡脾脏转移因子（ＳＴＦ）提取液，对照组注射０．５ｍｌ灭菌ＰＢＳ。第４、８周龄时分别采集血样，用酯酶染色法检测外周血Ｔ淋巴细胞百分率，用ＥＬＩＳＡ方法检测血清中鸡新城疫（ＮＤ）抗体滴度，同时取出胸腺、脾脏、法氏囊称重。结果表明：注射ＳＴＦ能提高粤黄鸡外周虫Ｔ淋巴细胞百分率，并提高鸡血清中ＮＤ的抗体滴度，但脾脏与胸腺的相对     

3种不同方法检测雏鸡白痢病血清抗体的比较

３种不同方法检测雏鸡白痢病血清抗体的比较沈国顺，何昭阳，刘丽霞（沈阳农业大学，１１０１６１）（吉林农业大学）（沈阳农业大学）通过检疫方法清除带菌鸡是防制鸡白痢一种必不可少的手段，目前国内外对鸡白痢病的检疫仍较多地采用平板凝集反应试验，该方法易于现场操...     

鸡白痢沙门菌等位基因特异性PCR检测方法的建立

根据鸡白痢沙门菌与鸡伤寒沙门菌的rfbS基因在第237和第598位碱基的不同，设计和合成了等位基因特异性PCR引物，建立了快速检测鸡白痢沙门菌的PCR方法，并应用该方法对鸡白痢沙门菌临床分离样品进行了PCR鉴定。结果显示，该PCR方法能够特异性地鉴定鸡白痢沙门菌，检测灵敏度达100PgDNA。对35个经常规方法鉴定的鸡白痢沙门菌分离株应用等位基因特异性PCR方法进行鉴定，鉴定出33株鸡白痢沙门菌，符合率为94．3％。表明，建立的等位基因特异性PCR方法能够准确而快速地鉴定鸡白痢沙门菌。     

Cell-culture virus-neutralization test and enzyme-linked immunosorbent assay for evaluation of immunity in chickens against fowlpox

Two serological tests--the virus-neutralization (VN) test in chicken embryo fibroblasts (CEF) using a cell-culture-adapted virus, and the enzyme-linked immunosorbent assay (ELISA)--were used for evaluating the immune response in chickens against fowlpox virus. The VN test was conducted in 96-well tissue-culture plates using a fowlpox virus that was adapted to induce cytopathic effects (CPE) in CEF in 48 hr. The ELISA was carried out with an antigen prepared by precipitation of a cell-culture-propagated virus suspension with ammonium sulfate and concentration by centrifugation. A 0.1 M acetate buffer, pH 5, was used as the sensitizing solution for maximum specific binding of the antigen to the microplate plastic well. No antibodies were detected by the VN test in 228 serum samples taken from chickens at irregular intervals between 1 and 39 weeks of age, even though the birds were vaccinated against fowlpox at 13 weeks of age. However, in sera collected 4 weeks after a sample of laying hens was challenged with fowlpox virus, VN titers of 1/10 to 1/40 were detectable. On the other hand, significant antibody reactions were detected by the ELISA on sera from chickens during the growing period, following vaccination and challenge. Although no maternal antibodies were found at 1 week of age, a continuous increase in the mean ELISA titers to fowlpox was demonstrated during the entire experimental period. This study showed that the ELISA was considerably more sensitive and practical than the VN test.     

鸡痘母源抗体对重组鸡痘疫苗免疫效果的影响

为了检测抗鸡痘病毒母源抗体对喉气管炎重组鸡痘疫苗的影响,孵化一批来自禽痘病毒高免母鸡的雏鸡,采用ELISA方法检测鸡痘疫苗免疫鸡后代的血清抗体。检测结果表明,雏鸡自孵出2d开始,血清鸡痘病毒抗体水平就开始缓慢下降,到15日龄时下降至临界值,已有部分鸡开始出现抗体阴性反应;到21日龄时,全部被检血清抗体水平均转为阴性。分别于不同日龄对试验雏鸡免疫接种重组鸡痘疫苗,结果只有当鸡体内的鸡痘病毒母源抗体全部为阴性(21日龄)后免疫时才能产生可靠的保护作用,保护率达到80％以上。这说明鸡痘病毒母源抗体对重组鸡痘疫苗的效果有一定的影响,因此重组疫苗合理的首免时间应选择在3周龄以后。     

Antibody detection-based differential ELISA for NDV-infected or vaccinated chickens versus NDV HN-subunit vaccinated chickens

With the advent of subunit vaccines for microbial diseases it is becoming increasingly important to be able to differentiate naturally infected animals from those vaccinated with the corresponding subunit vaccine. For avian viruses such as Newcastle disease virus (NDV), a whole virus-based ELISA cannot make such a differential diagnosis since in both cases the antisera would react with the whole virus. The nucleocapsid protein (NP) gene of the NDV Hitchner B1 strain was cloned, sequenced and expressed to develop a differential ELISA. The B1 NP had 95.7 and 96.1% amino acid identities with the NP of the d26 and Ulster 2C strains, respectively. The B1 NP expressed in a baculovirus expression vector (recNP) was the expected size and reacted with NDV-specific antibodies (Ab) in Western blots and by radioimmunoprecipitation. The ELISA using recNP-coated wells, tested on serum samples from flocks pretested with a commercial NDV kit gave results corresponding to those of the kit. Furthermore, use of both the renNP-based ELISA and a whole virus ELISA allowed the differentiation of birds vaccinated and a NDV haemagglutinin-neuraminidase (HN) expressing fowlpox virus from birds infected with NDV. This provides the basis for establishing an ELISA that discriminates between the antibody response to a recombinant fowlpox vaccine (expressing NDV HN protein) and that to live and inactivated NDV.     

Immune responses of swine inoculated with a recombinant fowlpox virus co-expressing P12A and 3C of FMDV and swine IL-18

Two recombinant fowlpox viruses (rFPV-P1 and rFPV-IL18-2AP12A) containing foot-and-mouth disease virus (FMDV) capsid polypeptide, 3C coding regions of O/NY00 were evaluated to determine their abilities to induce humoral and cellular responses in the presence or absence of swine IL-18 as genetic adjuvant. The ability to protect swine against homologous virus challenge was examined. All swine were given booster vaccinations at 21 days after the initial inoculation and were challenged 10 days after the booster vaccination. Control groups were inoculated with wild-type fowlpox virus (wtFPV). All animals vaccinated with rFPV-P12A and rFPV-IL18-P12A developed specific anti-FMDV ELISA antibody and neutralizing antibody and T-lymphocyte proliferation was observed. Cellular immune function was evaluated via examination of IFN-gamma production in swine peripheral blood serum. The results demonstrate the potential viability of a fowlpox virus-based recombinant vaccine in the control and prevention of FMDV infections.     

禽痘病毒感染对禽流感重组禽痘病毒疫苗免疫效力的影响

表达禽流感病毒 (AIV)HA和NA基因的重组禽痘病毒rFPV_HA_NA能够诱导鸡体产生 10 0 %抵抗高致病性禽流感病毒 (HPAIV)H5N1的攻击。而当鸡群已进行禽痘疫苗免疫或者感染了禽痘病毒的情况下 ,此重组疫苗的免疫效力如何 ?首先用禽痘病毒S_FPV_0 17人工感染SPF试验鸡 ,既而在感染后的不同间隔时间接种重组疫苗 ,免疫后检测鸡群的HI抗体水平 ,同时用 10 0LD50 的HPAIVH5N1进行攻击。结果重组疫苗免疫与禽痘病毒人工感染时间间隔在 4周 (或以上 )时 ,预先感染禽痘病毒对重组疫苗的免疫效力不构成影响 ,对禽流感的保护力为 10 0 % ,而间隔时间在 1、2、3周时 ,重组疫苗的免疫保护效力则受到不同程度的影响。     

表达传染性支气管炎病毒S1基因重组鸡痘病毒的构建

将鸡传染性支气管炎病毒S1基因插入到鸡痘病毒转移载体pSY681中，获得重组转移载体pSY681。将pSY681-IBVS1转染已感染亲本鸡痘病毒S-FPV-017株的鸡胚成纤维细胞，使其在鸡胚成纤维细胞内与鸡痘病毒基因组发生同源重组，产生表达鸡IBVS1蛋白的重组鸡痘病毒rFPV-IBVS1。在含有X-gal的营养琼脂培养基上进行蓝斑筛选且进一步纯化14代。S1基因的PCR检测表明，获得的含传染性支气管炎病毒S1基因的重组鸡痘病毒能够稳定遗传，间接免疫荧光和Western blot等试验证实该重组病毒在CEF内真实地表达了分子量约为90Ku的具有免疫学活性的IBV S1糖蛋白。     

表达猪繁殖与呼吸综合征病毒ORF5/ORF6基因重组鸡痘病毒的构建与小鼠免疫试验

本试验构建了1株表达猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)RF5/ORF6基因的重组鸡痘病毒,并进行了小鼠免疫实验,对其诱导BALB/c小鼠产生体液免疫和细胞免疫反应的能力进行了评价。结果表明,重组鸡痘病毒能够刺激免疫鼠产生特异性PRRSV ELISA抗体,促进特异性T淋巴细胞增殖。对免疫小鼠血清中细胞因子检测结果表明,IFN-γ的分泌显著提高。结果表明,所构建重组鸡痘病毒可以对小鼠起到良好的免疫效果,具有成为抗PRRSV感染新型疫苗的潜力。     

共表达Asia1口蹄疫病毒P1-2A-3C基因和猪IL-18基因重组鸡痘病毒构建及表达

为构建Asia1型口蹄疫重组鸡痘病毒疫苗,采集口蹄疫发病牛的水泡液及水泡皮,用RT-PCR法扩增出Asia 1型口蹄疫病毒的前体蛋白基因P1-2A片段和蛋白酶基因3C片段,分别克隆至pMD18-T载体上,通过酶切连接获得质粒pMD18-T-P1-2A-3C。再将P1-2A-3C片段与pUTAL-IL18片段连接起来,构建鸡痘病毒中间转移质粒pUTAL-P1-2A-3C-IL18。通过脂质体转染法,将pUTAL-P1-2A-3C-IL18与鸡痘病毒282E4株共感染染鸡胚成纤维细胞（chicken embryo fibroblasts,CEF）,通过BrdU三次加压筛选,筛选出重组鸡病毒株vUTAL-P1-2A-3C-IL18。经RT-PCR和间接免疫荧光法鉴定,证明所筛选的1株重组鸡痘病毒在CEF中能正确表达P1-2A-3C基因。本研究为研制安全、高效的亚洲Ⅰ型FMD重组鸡痘病毒疫苗奠定了基础。     

H9亚型禽流感病毒HA基因的重组禽痘病毒构建

本试验构建了H9亚型禽流感病毒HA基因禽痘病毒转移载体,经转染、蓝斑克隆、筛选和纯化,获得了遗传性状稳定的HA基因重组禽痘病毒。提取感染重组病毒的鸡胚成纤维细胞(CEF)的DNA进行PCR扩增,获得1.7kb的携带有外源目的基因片段。收集纯化的重组病毒CEF细胞,用H9亚型禽流感病毒多克隆血清作一抗,碱性磷酸酶标记的鸡IgG为二抗进行Western blot检测,结果表明重组痘病毒能在体外的CEF细胞表达HA糖蛋白。     

Fowlpox virus: Pathogenicity and vaccination of day-old chickens via the aerosol route

Day-old chickens were given a single fowlpox virus vaccination (strain HP201) either via the aerosol or wing-web route. Both methods induced protective immunity against a wing-web or intravenous challenge with virulent fowlpox virus at 47 days old, although high titred virus preparations were required for successful aerosol vaccination. However, no clinical signs of infection were observed as a result of aerosol vaccination even if invasive strains of Escherichia coli were administered simultaneously. The use of aerosol fowlpox virus vaccination of day-old chicks has been shown to be a possible means of mass vaccination and could be applied to the use of fowlpox virus in recombinant vaccines.