用digoxigenin标记DNA探针检测鸡贫血病病毒感染

用ｄｉｇｏｘｉｇｅｎｉｎ标记鸡贫血病病毒（ＣＡＶ）衣壳蛋白基因的重组质粒克隆作为探针对江苏、上海等不同地区随机采集的６０￣１２０日龄病鸡或死亡鸡的胸腺抽提ＤＮＡ，进行Ｄｏｔ ｂｌｏｔ检测ＣＡＶ感染情况。在被检测的８４只鸡胸腺病料中，有２４只鸡的病料显示阳性（阳性检出率为２８．６％），这一结果表明，ＣＡＶ感染在我国鸡群中已很普遍，且引起严重的二重感染。     

PCR和斑点杂交检测鸡传染性贫血病毒

通过聚合酶链反应（ｐｃＲ）扩增鸡传染性贫血病毒（ｃＡＶ）ＤＮＡ特定片段，将此ｐｃＲ产物用Ｄｉｇｏｘｉｇｅｎｉｎ标记后作为探针进行斑点杂交，以此检测ＣＡＶ并作流行病学调查。对从江苏省不同地市随机采集的２月龄左右不同疾病的病鸡ＤＮＡ样品进行检测，在被检的５２个不同鸡群来源的病料中，有３６个鸡群来源的病料ＤＮＡ显示ＣＡＶ阳性（群阳性率为６９．２％）；备组织中ＣＡＶＤＮＡ含量有所差异，依次为胸腺＞脾、骨髓、肝＞肾、法氏囊、脑。用ＰＣＲ检测得到的阳性鸡的组织病料感染ＳＰＦ鸡，在感染后第２４天检查，出现贫血症状。初步调查表明，在江苏一些地区ＣＡＶ感染已相当普遍，但它与发病的关系还有待于进一步研究。     

鸡传染性支气管炎可疑病料的病毒分离及初步鉴定

１９份鸡传染性支气管炎（ＩＢ）可疑病料通过ＳＰＦ鸡和鸡胚感染试验、血凝（ＨＡ）试验、气管环培养（ＴＯＣ）感染试验、单克隆抗体（Ｍａｂ）ＥＬＩＳＡ和电镜形态学观察，初步证明其中１３份病料含ＩＳ病毒（ＩＢＶ）．在用其中９份接种８～９周龄ＳＰＰ鸡进行的发病试验中，全部呈现临床症状，其中３份引起病死亡率（６０～８０％），接种后５周从存活鸡采血作ＩＢＶ血凝抑制（ＨＩ）试验，结果均为阳性．     

PCR、斑点杂交及间接免疫荧光试验对鸡传染性贫血病临床诊断的应用比较

应用能特异性扩增出鸡传染性贫血病毒（ Ｃ Ａ Ｖ） ０５８ ｋｂ Ｄ Ｎ Ａ 的已知引物，对江苏某地区疑为 Ｃ Ａ Ｖ感染的 １５～３０ 日龄病鸡的肝 Ｄ Ｎ Ａ 样品进行了 Ｐ Ｃ Ｒ 扩增。结果，在被检的 ２０ 份样品中，有 ６ 份为 Ｐ Ｃ Ｒ 阳性，阳性率 ３０％ 。利用地高辛标记的 ０８５ ｋ ｂ 的 Ｃ Ａ Ｖ 核酸探针对相同样品进行斑点杂交，结果与 Ｐ Ｃ Ｒ 扩增相同。对应的病鸡血清经间接免疫荧光试验（ Ｉ Ｉ Ｆ Ａ）发现，有 ７ 份为 Ｃ Ａ Ｖ 抗体阳性，与 Ｐ Ｃ Ｒ 扩增结果的符合率为 ７７％ 。初步结果表明，江苏某地区存在 Ｃ Ａ Ｖ 感染， Ｉ Ｉ Ｆ Ａ 与 Ｐ Ｃ Ｒ 的结果有差异     

伊氏锥虫抗独特型抗体疫苗的研究：Ⅲ.伊氏锥虫变异表面糖蛋白抗独特…

用提纯的Ａｂ２制成免疫制剂，在大白鼠、小白鼠可诱导特异性ＶＳＧ抗体（Ａｂ３）。免疫保护试验结果表明，Ａｂ２制剂免疫动物对攻虫感染具有明显的保护效应。单独用抗独特型抗体免疫的小白鼠、大白鼠、豚鼠对５０条同型锥虫攻击的保护率分别为６０％，６０￣８０％，８０％；抗独特型抗体作为“引子”，可使小白鼠获得８０￣１００％的保护，对大白鼠和豚鼠和保护率为１００％。单独使用抗独特型抗体免疫的小白鼠对５个数量（２５     

减蛋综合征病毒33K蛋白基因克隆及结构分析

纯化的减蛋综合征病毒（ＥＤＳＶ）ＤＮＡ经ＨｉｎｄⅢ水解、０．８％琼脂糖电泳后,回收各ＤＮＡ条带并克隆至ｐＢｌｕｅｓｃｒｉｐｔＫＳ载体,建立了ＥＤＳＶ基因文库,对３３Ｋ蛋白基因进行了分析。本研究证实,ＥＤＳＶ３３Ｋ蛋白基因含有２个外显子,与羊腺病毒（ＯＡＶ）３３Ｋ蛋白比较,Ｎ端编码产物的同源性为３０．８％,Ｃ端的为６０％。用ＲＴ－ＰＣＲ扩增３３ＫｍＲＮＡ和ｃＤＮＡ克隆及序列分析证实,ＥＤＳＶ３３Ｋ蛋白含有８２碱基（ｎｔ）的内含子,去掉内含子３３Ｋ蛋白基因能形成完整的ＯＲＦ,其编码产物由１７７氨基酸（ａａ）组成,推测分子质量为２．０６×１０４,与人５型腺病毒和ＯＡＶ的同源性分别为２８．１％和４４．７％。     

双抗体夹心ELISA检测牛病毒性腹泻病毒的研究

建立了从粪便中检测牛病毒性腹泻（ＢＶＤ）病毒抗原的双抗体夹心ＥＬＩＳＡ。试验方法的最佳工作条件为，抗体包被量为１００μｇ／孔，酶标抗体的浓度为１：４００。对不同地区牛、羊、鹿粪样检测结果，牛的ＢＶＤＶ感染率为１６．５％￣８９．０％，羊为１４．６％￣８３．３％，鹿为１９．６％￣４４．４％，并且从许多地区的牛、羊同时检测到ＢＶＤＶ，表明本病在国内某些地区存在着严重的感染。     

鸡贫血病毒荷兰弱毒株基因序列比较研究

用ＣＡ５、ＣＡ６和ＣＡ７、ＣＡ８两对引物对鸡贫血病毒荷兰弱毒株进行ＰＣＲ扩增。将扩增产物１．５ｋｂ和０．８ｋｂ的ＤＮＡ片段分别克隆到ＰＵＣ１１９、ｐＢｌｕｅｓｃｒｉｐｔ载体质粒中,并进行核苷酸序列分析。通过与２６Ｐ４毒株进行核苷酸序列比较发现二者有３２个核苷酸的差异。荷兰和２６Ｐ４两毒株间ＶＰＩ蛋白质同源率为９７％,没有发生特异性变化;ＶＰ３蛋白质同源率为９５％,在Ｉ￣３０个氨基酸之间发生了特异性     

磷酸钙介导马立克氏病病毒DNA转染鸡胚成纤维细胞

提取马立克氏病病毒（ＭＤＶ）Ｒｉｓｐｅｎｓｅ株感染的鸡胚成纤维细胞（ＣＥＦ）总ＤＮＡ，运用磷酸钙－ＤＮＡ沉淀转染ＣＥＦ，可以成功地得到ＭＤＶ的病变空斑。用每份沉淀含２０μｇ的ＭＤＶ和细胞总ＤＮＡ转染次代ＣＥＦ，其转染形成空斑的数量为４－２２１个，转染频率约为１－０＾－６＝１０＾－５；将磷酸钙－ＤＮＡ沉淀加入到ＣＥＦ中，于３７℃５％ＣＯ２培养箱中培养４ｈ后，室温下用１５％甘油休克２ｍｉｎ，由此可以提     

北京地区腹泻犬细小病毒感染情况调查

在校动物医院用试剂盒对１３６例门诊腹泻犬粪便进行犬细小病毒（ＣＰＶ）检验，其中阳性７２例（阳性率５２．９％）。阳性病例中，公犬占５２．４％，母犬占５１．６％，因此ＣＰＶ感染与犬性别无关。ＣＰＶ阳性率，以２～４月龄大为最高（６０．３％），５～６月龄次之（１７．６％）。７月龄以后较少。未注射或未按程序注射ＣＰＶ疫苗犬，ＣＰＶ检验阳性率高，即使按程序接种ＣＰＶ疫苗的犬，也仍有感染ＣＰＶ的，其原因有待研究．     

Polymerase chain reaction amplification for direct detection of chicken anemia virus DNA in tissues and sera.

Direct detection of chicken anemia virus (CAV) DNA in tissues and sera was investigated by a polymerase chain reaction (PCR) assay. Using a pair of primers constructed to amplify the coding sequence of the CAV DNA genome, the PCR assay was shown to be extremely sensitive, being able to detect 1 fg of CAV replicative form DNA. The oligonucleotide primers used for the PCR yielded 583 base-pair (bp) amplified product, which was sized by ethidium bromide-agarose gel electrophoresis. Tissue samples from seven cases of suspected chicken infectious anemia were obtained for CAV isolation. DNA extracted from the homogenized suspension of pooled tissues of each case was analyzed by the PCR assay. Results showed that five of the seven cases were positive for CAV DNA by PCR, whereas CAV was isolated from four cases only. The PCR assay also detected CAV DNA in two of 37 serum samples from disease-free chickens. The specificity of PCR was confirmed by chemiluminescence dot-blot analysis of the amplified products.     

我国白羽肉用型鸡群中CAV、REV和REOV感染状况的血清学调查

为了解鸡传染性贫血病毒（CAV）、禽网状内皮增生病病毒（REV）和呼肠孤病毒（REOV）在我国白羽肉用型鸡中的感染状态，在2003—2004年，检测了来自5省市8个公司不同年龄鸡群血清样品中3种病毒抗体的存在状况。结果表明，在送检的75个鸡群中，对CAV、REV和REOV呈现抗体阳性的鸡群分别有64个（85．3％）、36个（48％）和74个（96％）。在总共检测的1764份血清样品中，对这3种病毒的平均抗体阳性率分别为51．4％、9．8％和75．1％。在1日龄雏鸡，对CAV和REOV的平均母源抗体阳性率可达100％和81．1％，但对REV只有7．4％。抗体阳性率随年龄变化的动态分析表明，对REV和REOV的母源抗体在出壳后2～3周内消失，而对CAV的母源抗体则可持续3～4周。对CAV和REOV的抗体从5周龄起再次出现，到20周龄时，所有送检鸡群全部阳性，平均阳性率在90％以上。有近一半送检鸡群对REV呈现抗体阳性，抗体阳性率普遍较低，即使在达到开产年龄后，仍还有很高比例鸡为抗体阴性，即对REV仍为易感鸡。研究表明，我国多数鸡群中都同时存在着这3种病毒的感染，但它们在感染的程度和动态等流行病学特点上显著不同，应根据鸡群中抗体的阳性率分别采取不同的措施。     

Serological evidence of chicken infectious anemia virus in the United States at least since 1959

A retrospective, serological survey was performed to determine an approximate time frame for when chickens were first exposed to chicken anemia virus (CAV) in the southeastern United States. A serum collection covering most of the period between 1959 and 2005 was available for the present study. These sera were obtained from adult chicken flocks that were maintained in experimental chicken farms at Auburn University's Department of Poultry Science. Sera were tested for the presence of CAV-specific antibodies using a commercially available competitive enzyme-linked immunosorbent assay (ELISA) kit. Values <0.6 were considered positive. Fresh sera obtained from hens in 2005 showed 45.5% negative and 54.5% positive for CAV antibodies. The assessment of serum samples covering the time period of 1959 through 1979 resulted in most sera being positive for CAV antibodies. The percentage of positive samples between years varied from 43% to 100%. These serological results support assumptions based on circumstantial evidence that CAV must have been present in the United States long before its first isolation in 1989.     

Genetic characterization of chicken anemia viruses newly isolated from diseased chicks in Japan in 2020

In this study, a total of nine chicken samples obtained from two broiler flocks in Oita and Tottori prefectures in 2020 were examined for Chicken anemia virus (CAV) infection. The samples were collected from clinically suspected flocks and diseased chickens. The CAV genome was detected in all nine samples tested by real-time PCR. Phylogenetic analyses and sequence comparisons of the full-length VP1 gene sequences indicated that all the Japanese CAV strains obtained in this study formed a similar cluster of genotype III and shared high nucleotide (99.62–100%) identity. The current Japanese CAV strains were closely related to Chinese CAV strains but not related to vaccine strains. One positive selection site of VP1 was detected among the Japanese CAV strains.     

山东省鸡传染性贫血流行病学调查

本文对山东省12个地市58个鸡群传染性贫血的流行情况进行了调查,共检测了368份血清样品,蛋鸡群、肉鸡群和种鸡群的鸡传染性贫血病毒(CAV)ELISA抗体检出率分别为91.7%、77.6%和84.78%,平均抗体阳性率为83.2%,结果表明近几年山东省鸡群中CAV感染相当普遍,而且蛋鸡和种鸡抗体阳性率明显高于肉鸡群。     

Detection of chicken anemia virus DNA in the thymus of naturally infected chicks in turkey.

In this study, 94 clinically ill 11-28-day-old chicks belonging to eight broiler units from the Marmara region were investigated clinically for changes in hematocrit values and for the presence of chicken anemia virus (CAV) DNA. CAV DNA was detected by polymerase chain reaction in the thymus of 8.5% of the chicks. These chicks showed clinical signs of diarrhea, anorexia, depression, and growth retardation. The hematocrit values of these chicks were between 24% and 38%. At necropsy, hemorrhages were observed in the leg and pectoral muscles. Atrophy was noted in the thymus and in the bursa of Fabricius of positive chicks, and hemorrhages in the proventriculus of one positive chick were observed. This report describes the first detection of CAV DNA in chicks in Turkey.     

Detection of chicken anemia virus in the gonads and in the progeny of broiler breeder hens with high neutralizing antibody titers

Previous evidence for the presence of chicken anemia virus (CAV) in the gonads of immune specific-pathogen-free chickens raised the question whether this occurs also in commercial breeders. The presence of CAV was investigated by nested PCR in the gonads and spleens of hens from two 55- and 59-week-old, CAV-vaccinated (flocks 2 and 3), and two 48- and 31-week-old non-vaccinated broiler breeder flocks (flocks 1 and 4). In addition, lymphoid tissues of 20-day-old embryos from these hens were also investigated for the presence of CAV. CAV was detected in the gonads and of 5/6 and 11/22 of the vaccinated hens and in some hens also in the spleen alone. Embryos from 7/8 and 5/18 of these hens were positive. In the non-vaccinated flocks, CAV was detected in the gonads of 11/34 and 10/10 hens in flocks 1 and 4, respectively. In addition, 11 birds in flock 1 had positive spleens. CAV DNA was detected in 3/11 and 2/10 of their embryos. CAV-positive gonads and embryos were detected in samples from hens with moderate as well as high VN antibody titers. Vaccinated chickens positive for CAV in the gonads and in their embryos had VN titers ranging from >1:512 to <1:2048. In non-vaccinated chickens, the VN titers of CAV positive chickens ranged from 1:128 to 1:4096. These results demonstrate that CAV genome can remain present in the gonads of hens in commercial broiler breeder flocks even in the presence of high neutralizing antibody titers that have been associated with protection against CAV vertical transmission. It also suggests that transmission to the progeny may occur irrespectively of the level of the humoral immune response in the hens.     

Development and comparison of serologic methods for diagnosing chicken anemia virus infection.

This paper describes the development of an indirect immunoperoxidase assay (IIP) and an indirect enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to chicken anemia virus (VAC). The IIP assay developed used CAV-infected MDCC-MSB1 cells for detecting antibody to CAV, whereas the ELISA utilized gradient-purified immunoadsorbed CAV as the target antigen. The IIP and ELISA were compared with the standard indirect immunofluorescent antibody (IFA) assay, which is more conventionally used to screen chicken serum for antibodies against CAV. Comparative test results of 185 field samples of chicken serum by these three methods were in agreement 84% of the time. Both IFA and IIP assays yielded fewer positive tests than did the ELISA. IFA and IIP assays were in agreement 93% of the time, as compared with 91% agreement of IIP and ELISA results, or 84% agreement for comparative IFA and ELISA results.