江西地方品种鸡禽白血病病毒感染状况的研究

为了解江西省地方品种鸡群中禽白血病病毒的感染状况,利用针对禽白血病病毒(ALV)J亚群抗体和群特异性P27抗原的商品化ELISA检测试剂盒,对江西省12个种鸡企业的6个地方品种鸡进行禽白血病感染情况调查。结果显示江西几个地方品种鸡ALV的感染相当严重,迫切需要净化。但不同品种鸡的P27抗原的检出率与ALV-J抗体的检出率有一定差异。P27抗原阳性率最高的为JXDF4品种鸡(36.67%),其次为JXDF5、JXDF1、JXDF3、JXDF6、JXDF2品种鸡。与P27抗原检出情况类似,JXDF4、JXDF5的ALV-J抗体阳性率相对较高,分别为15%、30%,而其他4个地方品种的鸡群ALV-J抗体阳性率相对较低(10%)。调查还显示,同一品种鸡在不同种鸡场之间的ALV-J感染率差异较大。试验结果为各种鸡场开展净化工作提供了科学依据。     

江西地方品种鸡禽白血病病毒及鸡白痢沙门氏菌感染状况的研究

禽白血病毒(ALV)和鸡白痢沙门氏菌(SP)均可以垂直传播。通过禽白血病病毒(ALV)J亚群抗体和群特异性P27抗原的商品化ELISA检测试剂盒和全血平板法等调查了江西省13个种鸡企业的8个地方品种鸡群ALV和SP的感染情况,结果显示:ALV-P27抗原、ALV-J抗体均有检出,江西省地方鸡ALV-J亚型感染相当严重,迫切需要净化。江西地方品种鸡白痢沙门氏菌感染率相差较大,同一品种鸡在不同场之间的SP感染率差异明显。生物安全措施会影响鸡白痢的感染情况,在鸡白痢的净化过程中,采取严格的淘汰制度的同时,必须加强饲养管理措施来控制鸡白痢的发生。     

江西地方品种鸡禽白血病病毒及鸡白痢沙门氏菌感染状况的研究

禽白血病毒(ALV)和鸡白痢沙门氏菌(SP)均可以垂直传播。通过禽白血病病毒(ALV)J亚群抗体和群特异性P27抗原的商品化ELISA检测试剂盒和全血平板法等调查了江西省13个种鸡企业的8个地方品种鸡群ALV和SP的感染情况,结果显示:ALV-P27抗原、ALV-J抗体均有检出,江西省地方鸡ALV-J亚型感染相当严重,迫切需要净化。江西地方品种鸡白痢沙门氏菌感染率相差较大,同一品种鸡在不同场之间的SP感染率差异明显。生物安全措施会影响鸡白痢的感染情况,在鸡白痢的净化过程中,采取严格的淘汰制度的同时,必须加强饲养管理措施来控制鸡白痢的发生。     

河南某鸡场地方品种鸡禽白血病病毒感染状态检测

为了解河南某鸡场地方品种鸡禽白血病病毒(Avian Leukosis Virus,ALV)感染状态,采集该鸡场绿壳蛋鸡、青脚麻鸡和固始鸡的泄殖腔棉拭子、蛋清和血清,利用ELISA方法检测泄殖腔棉拭子、蛋清和血清样品中的ALV-p27抗原及血清样品中ALV-A/B和ALV-J抗体的水平,同时采集其血液接种DF-1细胞进行外源性ALV的分离鉴定。结果表明,绿壳蛋鸡泄殖腔棉拭子、蛋清和血清中的ALV-p27抗原阳性率分别为23.55%、11.96%和26.63%,血清中ALV-A/B和ALV-J抗体的阳性率分别为30.43%和16.85%,外源性ALV的分离阳性率为13.04%;青脚麻鸡泄殖腔棉拭子、蛋清和血清中抗原阳性率分别为10.99%、5.43%和22.83%,血清中ALV-A/B和ALV-J抗体的阳性率分别为18.48%和6.52%,外源性ALV的分离阳性率为8.00%;固始鸡泄殖腔棉拭子、蛋清和血清中抗原阳性率分别为21.07%、12.32%和25.00%,血清中ALVA/B和ALV-J抗体的阳性率分别为28.26%和17.39%,外源性ALV的分离阳性率为12.50%。表明3个地方品种鸡都不同程度地感染外源性ALV,且可能存在ALV-A/B和ALV-J 2种或3种亚群同时感染。     

商品代罗曼蛋鸡发生禽J-亚群白血病

安徽某商品代罗曼蛋鸡场360日龄产蛋鸡出现渐进消瘦、瘫痪、脚底流血和最后死亡现象,发病期内全群死亡率达7%左右。经对6只病鸡解剖发现,大多数肝、脾等内脏器官明显肿大,有的表面可见大小不一的灰白色结节,共同的特征病变是在胸骨内面、肋骨等处出现黄豆至蚕豆大小的白色肿瘤样结节,疑似禽J-亚群白血病。对发病鸡群随机采集血液样本35份,经禽J-亚群白血病ELISA试剂盒检测,阳性感染率达5.71%,从而确诊该商品代罗曼蛋鸡发生的骨性肿瘤病为禽J-亚群白血病。商品代罗曼蛋鸡发生禽J-亚群白血病的报道在国内外尚属首次。     

地方鸡禽白血病病毒感染调查及主要流行亚群分析

为了解湖北省地方鸡禽白血病病毒的感染状态及主要流行亚群,从麻城绿壳蛋鸡、江汉鸡、景阳鸡3个地方品种核心群采集了7 477份样品,进行蛋清p27抗原检测、公鸡病毒分离鉴定及分离株gp85基因序列分析。结果显示:3个地方鸡种蛋清p27抗原阳性率分别为1.32%、6.54%和2.82%,公鸡病毒分离率为6.11%、30.14%和8.64%,表明湖北省地方鸡禽白血病病毒感染比较严重,不同品种的感染率不同,公鸡的排毒率高于母鸡。利用PCR方法将分离的15株禽白血病病毒分为两大亚群,分离株gp85基因遗传进化分析结果显示,3个地方鸡品种主要流行J、K亚群禽白血病病毒,均存在J、K亚群禽白血病病毒的共感染,表明湖北省地方鸡禽白血病病毒感染情况较为复杂。     

江苏省禽J亚型和AB亚型白血病共感染的血清学调查

[目的]进一步了解江苏省鸡群白血病的感染情况。[方法]从2011年3月到2012年5月在江苏省部分地区的鸡场随机采样600份,通过酶联免疫吸附试验(ELISA)检测J亚型白血病(ALV-J)和AB亚型白血病(ALV-AB)的抗体阳性率。[结果]江苏省的大多数鸡场均存在白血病的感染,其中ALV-J和ALV-AB为阳性的鸡场均有10个,ALV-J最高阳性率达35.56%,ALV-AB最高阳性率为15.56%,共感染的阳性率最高达6.90%。ALV-J、ALV-AB感染的年龄段存在一定差异,感染率最高的年龄段是12～24周龄;黄羽肉鸡和麻鸡ALV-J、ALV-AB感染率都较高,蛋鸡也存在ALV-J感染的情况,表明近年来J亚型白血病的宿主范围正在进一步扩大。[结论]该研究为进一步开展鸡白血病的净化工作提供了一定的依据。     

云南省昆明地区种鸡J亚群禽白血病血清学调查

[目的]了解云南省昆明地区种鸡场J亚群禽白血病的感染状况。[方法]从云南省昆明市疑似感染禽白血病的某种鸡场采集644份泄殖腔(公鸡)拭子和460份蛋清(母鸡)样品,采用ELISA法对种鸡J亚群禽白血病进行抗原检测。[结果]在检测的460份蛋清样品中,172份抗原呈阳性,阳性率为37.39%;在检测的644份泄殖腔拭子中,520份抗原呈阳性,阳性率为80.75%。A养殖场共检测644份样品,总阳性率为63.66%,其中蛋清样品的阳性率为39.13%,泄殖腔样品的阳性率为82.07%。B养殖场共检测460份样品,总阳性率为61.30%,其中蛋清样品的阳性率为34.78%,泄殖腔样品的阳性率为78.99%。此次检测结果表明云南省昆明地区种鸡群已严重感染J亚群禽白血病。[结论]该研究可为种鸡J亚群禽白血病的防治提供理论依据。     

福州市周边蛋鸡场禽白血病亚群的血清流行病学检测

应用ELISA方法对分别采集自福州市周边30个蛋鸡场的597羽海兰蛋鸡、512羽罗曼蛋鸡、486羽伊莎蛋鸡和553羽特佳蛋鸡共2148羽的血样进行禽白血病病毒(ALV)亚群ALV-A/B和ALV-J抗体检测.结果表明:样品ALV-A/B抗体阳性率由高至低依次为:特佳蛋鸡群11.39%(63/553)、罗曼蛋鸡群11.32%(58/512)、海兰蛋鸡群8.54%(51/597)和伊莎蛋鸡群7.61%(37/486);样品ALV-J抗体阳性率由高至低依次为:特佳蛋鸡群5.24%(29/553)、罗曼蛋鸡群4.10%(21/512)、伊莎蛋鸡群3.51%(13/486)和海兰蛋鸡群3.18%(19/597);而样品ALV-A/B抗体总阳性率为9.73%(209/2148),高于ALV-J抗体总阳性率3.82%(82/2148),其中有0.70%(15/2148)的ALV-A/B和ALV-J抗体双阳性样品;蛋鸡场ALV-A/B抗体阳性率为70.00%(21/30),高于ALV-J抗体阳性率36.7%(11/30),其中有16.7%(5/30)的ALVA/B和ALV-J抗体双阳性样品.结论:福州市周边蛋鸡场不同品系和不同鸡群间存在不同程度的ALV流行,相比ALV-J,ALV-A/B流行更普遍,且存在ALV-A/B和ALV-J抗体双阳性样品,应予重视.     

湖北部分肉种鸡群J亚群禽白血病血清学调查及PCR检测

采用间接ELISA和ALV-J特异性PCR方法,对湖北省荆州市的两个肉种鸡场共94只淘汰肉种鸡进行J亚群禽白血病血清学调查和ALV-J前病毒核酸检测.两个鸡场共检测出13份ALV-J抗体阳性血清和11份核酸阳性样品,抗体阳性率分别为13.2%和14.6%,核酸阳性率分别为11.3%和12.2%.血清学调查和PCR检测结果表明,湖北鸡群已存在J亚群禽白血病.     

实验感染肉鸡组织中J亚群禽白血病病毒的抗原定位

从实验感染J亚群禽白血病病毒(ALVJ)的髓细胞性白血病肉鸡病例中,选取典型病例,用J亚群禽白血病病毒单克隆抗体通过免疫酶组化试验对不同组织进行了抗原定位观察。结果显示:在实验感染阳性肉鸡体内实质组织细胞及瘤细胞的核膜和细胞浆里可见不同程度的棕黄色阳性反应,可为探讨ALVJ对体内组织细胞的嗜性提供依据。     

Study on the Pathogenicity of Chinese Strains of Subgroup J Avian Leukosis Viruses

The pathogenicity of 4 Chinese strains of subgroup J avian leukosis viruses (ALV-J), SD9901,SD9902, YZ9901 and YZ9902, was studied. The results showed that only SD9902 among the 4 strains induced mortality from myeloid leukosis (ML). In the 12 meat-type chickens inoculated with SD9902 at 1-day-old, 9died between 22 days and 38 days after inoculation. No death or ML was found in chickens inoculated with the other 3 strains during the period of 6 months. These results suggested the SD9902 strain of ALV-J was an acute transforming virus, but SD9901, YZ9901 and YZ9902 were non-transforming viruses. All 4 Chinese strains did not induce any tumors in egg-type SPF chickens during 7 months after hatching when viruses were injected into 11-day-old embryos.     

草鸡J亚群禽白血病病毒的PCR检测

通过对GenBank发表的ALV的基因序列的分析,针对J型ALV保守区设计并合成1对特异性引物。通过对反应条件的优化,确定了检测ALV的PCR检测方法,对来源于江苏地区不同草鸡养殖基地的10份病料组织样本提取DNA进行PCR扩增。结果对疑似J亚群ALV病料和正常鸡肝脏组织的病原核酸检出率分别为90%和0,同时将扩增的目的基因进行克隆测序,并与GenBank中的参考毒株进行比较,结果表明目的基因片段序列长300 bp左右,与参考毒株核苷酸序列同源性为97%以上。试验表明,江苏地区草鸡群中确实存在J亚群鸡白血病病毒感染的情况。     

An Evaluation of the Infection Status and Source of Subgroup J Avian Leukosis Virus in Cloned Free-Range Layers

In recent years, subgroup J avian leukosis virus (ALV-J) has been found to frequently infect layers in China. This virus is responsible for economic losses due to both mortality and decreased performance in chickens. In this study, 45-d-old cloned free-range layers were suspected to be infected with ALV and other immunosuppressive diseases because their feathers were unkempt and their growth rate was impaired. To estimate the infection status and determine the source of ALV-J in the flock, 30 cloacal swabs were randomly collected to measure the p27 antigen level by enzyme-linked immunosorbent assay (ELISA). Among the birds that were tested, 87% (26/30) were positive. In addition, 6 anticoagulant blood samples were aseptically collected at random from the flock when the layers were 60 d old. These samples were centrifuged to obtain the leukocytes, which were then used to inoculate chicken embryo fibroblast (CEF) cells for the identification of ALV-J by indirect immunofluorescence (IFA). Of the samples tested, 100% (6/6) were positive. The flock's production performance was also investigated, and 10 layers were necropsied to evaluate pathological changes at 115 d of age. The flock never laid eggs even though they reached the age of the first laying (110 d). Furthermore, there were pathological changes present, including atrophy of the thymus and bursa of Fabricius, undeveloped ovaries, glandular stomach haemorrhage, and hepatosplenomegaly. Paraffin-embedded sections of intumescent liver and spleen were prepared for antigen localisation using IFA. Positive signals were prevalent in paraffin-embedded sections of the intumescent liver and spleen. Furthermore, provirus DNA was extracted from 4 cloned free-range layers, and 2 paternal parents (HR native cocks), and the gp85 gene of ALV-J was amplified by PCR to analyse the genetic variation. The results of the autogenous variation analysis showed that the 6 strains were 98.5–99.7% homologous. This study indicated that there was persistent infection with ALV-J by dynamic inspection, which seriously reduced the production performance of the flock. In addition, the genetic variation analysis showed that ALV-J in the flock was more likely to have originated from the paternal parent, the HR native cock.