山东省肉种鸡群三种家禽肿瘤性疾病流行病学调查

为调查山东省家禽肿瘤性疾病的流行情况,本研究以血清学、病理组织学、免疫组织化学、病原学等检测手段,在山东省境内17家AA种鸡场进行检测.血清学试验结果显示:马立克氏病病毒(MDV)平均抗原阳性率为1.87%;禽白血病病毒J亚群(ALV-J)和网状内皮组织增生症病毒(REV)平均抗体阳性率分别为9.52%和39.78%;双重及三重感染,MDV+ALV-J、MDV+REV、ALV-J+REV及MDV+ALV-J+REV感染率分别为1.12%、1.21%、3.92%和0.65%.对57羽疑似肿瘤病的病鸡检测显示:MDV、ALV-J和REV的抗体阳性率分别为19.3%、47.37%和57.89%;MDV+ALV-J、MDV+REV和ALV-J+REV的双阳性率分别为1.75%、3.5%和19.3%;无三重感染.病理组织学观察显示:病鸡体内既有各病毒引起的单纯肿瘤,也有双重肿瘤共存的现象.免疫组织化学检测显示,MDV、ALV-J和REV抗原阳性信号在病鸡中的比例分别为38.6%、54.39%和28.07%.PCR检测结果表明:MDV、ALV-J和REV的阳性率分别为43.86%、64.91%和33.33%;MDV+ALV-J、MDV+REV、ALV-J+REV和MDV+ALV-J+REV阳性率分别为15.79%、10.53%、12.28%和7.02%.本研究结果表明,山东省境内AA肉鸡群中仍存在较高的肿瘤性病毒感染率.     

散养淮南王土鸡J亚群禽白血病的诊断

对湖北省某农户散养的12周龄淮南王土鸡病鸡进行剖检,发现病鸡肝脏有白色肿瘤;心肌增厚,有疑似肿瘤赘生物;脾脏萎缩,切面呈暗色。用J亚群禽白血病病毒（ALV-J）特异性引物进行PCR检测,扩增出了约545 bp的条带,病鸡组织内含有ALV-J病毒核酸序列,表明该病例为ALV-J感染。     

散养土鸡J亚群禽白血病病毒和网状内皮组织增生症病毒混合感染的诊断

湖北某农户散养的土鸡,鸡群精神委靡、整体消瘦,对病鸡进行剖检,发现部分鸡体表和脏器可见大小不等的肿瘤结节。取病变典型的组织制作病理切片,镜检可看到髓样细胞瘤和网状细胞。提取病鸡组织DNA,用两组Multi-PCR分别检测A、B、J亚群禽白血病病毒(ALV-A、ALV-B、ALV-J)和马立克病病毒(MDV)、禽网状内皮增生症病毒(REV)。结果仅扩增出与ALV-J和REV相应的条带,表明该鸡群为ALV-J和REV混合感染。     

J亚群白血病的病理学观察及PCR诊断

从某肉种鸡场取疑似J亚群白血病的自然发病鸡，剖检，观察病理学特征(光镜、电镜)。随后对该场进行ALV-J抗体ELISA检测，发现感染率达28％，从中选取部分抗体阳性鸡及阴性鸡剖检，取肝进行ALV-J特异性PCR检测。结果：自然发病鸡病变明显，在肝、脾、肾、睾丸(卵巢)肺等多种组织肿大，并有大小不等的灰白色结节。镜检：病灶内及肿瘤主要由密集的髓细胞组成，在大脑、小脑坐骨神经中未见。电镜，肿块中的髓细胞样瘤细胞呈圆形、核圆形或椭圆形，体积大小不一、染色质边集，胞浆中溶酶体增多，有些电子密度较高，有些趋于溶解，肝细胞体积增大，核浓缩或淡染，胞浆中线粒体增多，肿胀，嵴减少或消失，在胞浆膜下有病毒粒子存在。PCR结果：6例抗体阳性鸡和部分自然病例PCR阳性而2只对照鸡PCR阴性。通过以上证据可知，病变明显的和抗体阳性的鸡PCR结果全部为阳性，证明鸡体内病毒与抗体共存，而抗体阴性，病毒阳性的结果未出现，说明此肉种鸡场感染的ALV-J大部分是由于水平传播造成的。     

J亚型禽白血病病毒水平传播的试验

为探讨J亚型禽白血病病毒(ALV-J)的水平传播情况,选取0日龄60只抗原阴性鸡和20只抗原阳性鸡混合饲养,接触7 d、15 d、25 d、35 d、45 d、55 d、65 d、75 d、90 d后检测阴性鸡的泄殖腔ALV-p27和血清ALV-J抗体,并于65 d采集阴性鸡血浆接种DF-1细胞进行外源性ALV和J亚群分离鉴定。结果显示,阴性鸡与阳性鸡混合饲养15 d,泄殖腔中开始检测到ALV-p27抗原,65 d阳性率最高达50.00%;ELISA和RT-PCR方法检测到细胞培养液中外源性ALV阳性率分别为60.00%和56.67%;RT-PCR和IFA方法检测到细胞培养液中ALV-J抗原阳性率分别为56.67%和63.33%;65 d阴性鸡血清中ALV-J抗体阳性率达63.33%。表明阴性鸡与阳性鸡直接接触混合饲养,通过水平传播被感染外源性ALV-J的几率相当高。     

安徽省五华鸡J亚群禽白血病的鉴定及其病理学观察

为调查安徽省五华鸡J亚群禽白血病(Avian leukosis virus subgroup J,ALV-J)的感染情况,采用ELISA对五华鸡进行P27抗原和ALV-J抗体检测.挑选5只抗原抗体阳性鸡进行PCR检测,同时将5只抗原抗体阳性鸡和5只抗原抗体阴性鸡进行剖检,制作病理切片.其中1只鸡PCR检测为阳性,能扩增出545 bp条带,PCR检测阳性的鸡其心脏有肿瘤、脾脏肿大等病理学变化;组织切片发现心脏、肝脏、脾、肾、肺等组织内有弥漫性髓细胞样瘤细胞或髓细胞瘤病灶,髓细胞样瘤细胞的细胞质内可见嗜酸性颗粒.结果表明五华鸡已经感染了ALV-J,且部分鸡个体已经发病.     

黄羽父母代种鸡混合感染禽白血病病毒与马立克病病毒的鉴定

广西某养殖场130日龄父母代种鸡发生临床肿瘤样病变和死亡,对病鸡采用病理解剖、组织病理学观察、PCR检测、病毒分离以及分离株重要基因的序列测定和病原鉴定。结果显示:病鸡的心脏、肝脏、脾脏等部位表现有肿瘤样病变; PCR检测及病毒分离培养有J亚群禽白血病病毒(avian leukosis virus subgroup J,ALV-J)和马立克病病毒(Marek's disease virus,MDV)的感染; ALV-J分离株env基因的序列与10株ALV-J参考株的核苷酸相似性为87. 2%～97. 7%,与ALV A-E亚型参考株的相似性为53. 5%～54. 7%;与ALV-J英国原型株HPRS-103的env基因糖基化位点进行分析比较,部分糖基化位点发生了改变; MDV分离株meq基因序列与8株MDV参考株的核苷酸相似性为98. 7%～99. 4%,分离株在第71～80位氨基酸发生突变,符合国内强毒分离株的特征。结果说明:该鸡群为ALV-J和MDV的混合感染。     

百日鸡J-亚群禽白血病组织病理学与超微病理学研究

利用ELISA试剂盒,对百日鸡的禽白血病抗体和抗原进行了检测。在5个百日鸡父母代鸡群中,1个鸡群的ALV-J抗体阳性率为57.14%,其余鸡群皆为阴性;所有鸡群的ALV-A、B抗体均为阴性;ALV p27抗原除1个鸡群为阴性外,其余鸡群阳性率都较高。在百日鸡的J亚群禽白血病病例中,肝脏、脾脏和肾脏显著肿大,且有弥漫性分布的肿瘤结节;在其他脏器也呈现肿瘤结节。组织病理学观察,发现其脏器等组织中,有一定比例的胞质含红色嗜酸性颗粒的髓细胞样瘤细胞与成淋巴细胞,排列致密呈局灶性生长,正常的组织细胞被挤压或破坏。超微病理观察,在脾脏和法氏囊等组织中均看到病毒颗粒,有囊膜,直径约100nm。部分淋巴细胞核膜、细胞膜水肿或溶解破裂,线粒体和内质网也水肿或池变大、细胞质中出现很多空泡状结构。肿瘤细胞的增多以及细胞内和细胞间的水肿,可能是各脏器严重肿大的主要原因。     

麻黄鸡ALV-J、FAdV-4、FWPV混合感染的诊断

为了确定贵州省某规模养殖场病鸡发病的原因,本试验对发病鸡进行了临床剖检,取其鸡冠、肝脏、心脏、脾脏和肾脏等病料组织进行了细菌分离培养,并进行了鸡痘病毒(FWPV)、J亚型禽白血病病毒(ALV-J)和血清4型禽腺病毒(FAdV-4)的PCR检测。结果显示：实验室剖检可见病鸡存在鸡冠痘状结痂、肝脏肿瘤结节、心包积液、脾脏肿大等症状;细菌分离培养无菌落形成;基于ALV-J gp85、FAdV-4 penton、FWPV TK基因片段的PCR检测均呈阳性;随后的ALV-J gp85、FAdV-4 penton、FWPV TK基因克隆及序列分析进一步揭示了3种病毒的遗传进化状况。因此,送检病鸡确诊为ALV-J、FAdV-4、FWPV混合感染,依据确诊结果向有关养殖场提出了合理的防治措施建议。     

地方品种JS鸡多发肿瘤病的病原学分析

为探究江苏地方品种JS鸡种易发肿瘤病的原因,本研究从病原学方面进行相关分析。通过剖检发现JS鸡疑似发生肿瘤病;观察组织切片发现禽白血病病毒(ALV)、马立克病毒(MDV)引起其的特征性病变;分别应用2对可区分MDV野毒和疫苗毒的鉴别引物、1对ALV群特异性引物、5对可区分不同亚型ALV的鉴别引物,以及3对网状内皮组织增生症病毒(REV)特异性引物对病料样品和细胞培养物进行PCR检测;同时,采用间接免疫荧光试验(IFA)检测培养细胞中的禽REV,ELISA检测细胞上清中ALV-p27抗原。检测结果显示,鉴定出的MDV为血清1型MDV野毒,ALV为J亚型(ALV-J),REV为阴性。采集同群发病鸡血液分离MDV、ALV-J,将获得的病毒株人工接种1日龄SPF鸡,感染后5 d自实验鸡血液中分离到MDV、ALV-J,表明该分离株可感染SPF鸡,具有良好的生物学活性。本研究从JS品种鸡中检测到了致瘤性病毒MDV和ALV-J,这可能是该品种鸡肿瘤病多发的主要原因之一,这一研究结果对JS鸡肿瘤病的防制提供了科学依据。     

In vivo events of retroviral long terminal repeat integration into Marek's disease virus in commercial poultry: detection of chimeric molecules as a marker

The present study demonstrated, for the first time, that not only in vitro, but also in vivo, coinfections with Marek's disease virus (MDV) and each of the three avian retroviruses (reticuloendotheliosis virus [REV], avian lymphoid leukosis virus [ALV], and ALV-J) lead to retroviral long terminal repeat (LTR) integration into MDV. A total of 306 chicken and 59 turkey commercial flocks, submitted for differential avian oncogenic virus diagnosis, served to evaluate the flock mixed virus infection rate, the rate of birds with a multiple virus infection, and the issue of retroviral LTR integration into MDV in vivo. About a quarter of the tumor-bearing commercial flocks carried a mixed MDV and retrovirus infection. A total of 2926 DNA samples were analyzed, including 2428 chicken and 498 turkey DNA samples. Of these, 991 DNAs originated from flocks with a multiple virus infection. In 103 DNA preparations from that group (103/991, 10.4%), including 38 and 56 from chicken blood and tumor tissues, respectively, and nine samples from turkey blood, multiple virus sequences were detected by polymerase chain reaction (PCR). Fifty-six of the 103 samples were further analyzed by the previously developed hot spot-combined (HS-cPCR assay, of which 48% (27/56) contained chimeric MDV and retroviral LTR molecules. When extrapolated to the total samples derived from the flocks with multiple virus infection, that rate implies that about 5% of the DNA samples would carry MDV-retrovirus integration events. Several birds held a variety of chimeric molecules, indicating that several recombination events occurred simultaneously. The validation of the MDV and retroviral LTR chimeric constitution of these molecules was derived by the MDV and retroviral heterologous primers used for their creation by the HS-cPCR assay, Southern blotting and their detection by retroviral LTR probes, and LTR amplification from the gel-purified chimeric molecules. From several molecules, the LTR was sequenced, and a 161-bp retroviral LTR sequence was demonstrated. Our biochemical data imply that a recent integration occurred in the birds. The viability of recombinant viruses represented by the chimeric molecules will be further approached.     

The effect of the time interval between exposures on the susceptibility of chickens to superinfection with Marek's disease virus

Marek's disease virus (MDV) is ubiquitous within commercial poultry flocks because current vaccines do not prevent MDV infection or transmission. In order for newly-evolved MDV strains to become established within a flock, it seems inevitable that any new strain would need to infect and replicate in chickens previously infected with resident MDV strains. This phenomenon is difficult to detect and there is no clear evidence that it is even possible. Four experiments were performed to demonstrate superinfection and evaluate the effect of time between challenges on the effect of superinfection with the use of two pairs of fully virulent MDV strains that could be discriminated by novel technology: 1) JM/102W and rMd5//38CVI, and 2) rMd5 and rMd5//38CVI. Feather follicle epithelium (FFE), spleen, and tumor samples were collected at single or multiple time points from the same bird to determine the frequency and distribution of each virus present following superinfection, with the use of pyrosequencing and immunohistochemistry. Superinfection was observed in 82 of 149 (55%) FFE samples following short-interval challenge (24 hr) compared to only 6 of 121 (5%) samples following long-interval challenge (13 days), indicating a strong influence of challenge interval. In cases where the first inoculated virus was weak or delayed, the second inoculated virus was detected in 42 of 95 (44%) birds. In tumors from dually challenged birds, the second virus was again present much more often following short-interval challenge (68%) compared to long-interval challenge (11%). Virus mixtures in tumors were less common compared to those in FFE samples. Vaccination with turkey herpesvirus had no significant effect on the virus frequency for either virus pair or challenge time interval, suggesting these conclusions may be applicable to vaccinated chickens in the field. These studies demonstrated superinfection for the first time with two fully virulent MDV strains and suggest that short-interval challenge exposure and/or weak initial exposures may be important factors leading to superinfection--a prerequisite for the establishment of a second virus strain in the population. This model system should be useful to elucidate this important phenomenon further.     

广西猪繁殖与呼吸综合征病毒感染状况调查

采用RT-PCR技术,对2004年1月至2005年4月期间,广西13个市104个疑似猪繁殖与呼吸综合征病毒(PRRSV)感染猪场,无菌采取231头病、死猪的组织病料(肺脏、淋巴结、脾脏)进行了病毒检测。同时,对鉴定为PRRSV阳性的组织病料和猪场进行了猪圆环病毒2型(PCV2)、猪瘟病毒(CSFV)和猪伪狂犬病毒(PRV)的检测,以确定猪群中PRRSV与PCV2、CSFV和PRV混合感染情况。结果从12个市的115份组织病料中检出PRRSV,病料的平均阳性率为49.78%(115/231),猪场的平均阳性率为61.54%(64/104),不同地市有一定的差异。PRRSV与PCV2、CSFV和/或PRV二重或多重混和感染的组织病料总数为53份,猪场总数为39个,混合感染的组织病料和猪场的总阳性率分别为22.94%(53/231)和37.50%(39/104)。混合感染的组织病料占PRRSV阳性组织病料的46.09%(53/115),混合感染的猪场占PRRSV阳性猪场的60.94%(39/64)。其中以PCV2和PRRSV混合感染的组织病料和猪场数最多。由此可见,PRRSV感染在广西猪场已普遍存在,与其他病毒混合感染现象逐渐趋向复杂化。     

Use of nested polymerase chain reaction (PCR) for detection of retroviruses from formalin-fixed, paraffin-embedded uveal melanomas in cats

Thirty-six formalin-fixed, paraffin-embedded enucleated globes from cats with a diagnosis of diffuse anterior uveal melanoma were obtained. Sections of tumor were excised, deparaffinized, and subjected to nested polymerase chain reaction (PCR) to identify proviral DNA sequences from the feline leukemia virus (FeLV)–feline sarcoma virus (FeSV; 36 eyes), and the feline immunodeficiency virus (FIV; 18 eyes). All samples tested were negative for FIV DNA. Three samples were positive for FeLV–FeSV DNA. This is the first reported evidence of a possible link between naturally occurring feline anterior uveal melanoma and the presence of FeLV–FeSV DNA.     

牛病毒性腹泻病毒、牛呼吸道合胞体病毒和牛副流感病毒3型三重RT-PCR检测方法的建立及应用

根椐GenBank中牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)、牛呼吸道合胞体病毒(bovine respiratory syncytial virus,BRSV)和牛副流感病毒3型(bovine parainfluenza virus type 3,BPIV-3)3种病毒基因序列,设计合成引物,建立3种病毒的三重RT-PCR方法。用这3对引物对同一样品中的BVDV、BRSV和BPIV-3核酸模板进行三重RT-PCR扩增,结果显示:可同时扩增BVDV的466 bp,BRSV的735 bp和BPIV-3的258 bp的特异性片段,而对其他4种病原的PCR扩增结果均为阴性;敏感性测定结果表明,该三重RT-PCR技术能检出10 pg的BVDV、1 pg的BPIV-3和10 pg的BRSV模板。用37份临床病料对本研究多重RT-PCR技术和单项RT-PCR技术进行对比验证,结果显示:两者的总符合率为100%。结果表明:建立的多重RT-PCR检测方法,具有特异、快速、准确的特点,可用于对这3种病毒的同时检测和鉴别诊断。     

Serological detection of multiple retroviral infections in cattle: bovine leukemia virus, bovine syncytial virus and bovine visna virus

Individual experimental animals used in our studies on bovine leukemia virus (BLV) are routinely screened for the presence of antibodies to the three bovine lymphotropic retroviruses. We utilized these screening methods to examine frozen sera from eight herds for antibodies to BLV, bovine visna virus (BVV) and bovine syncytial virus (BSV). Serum samples from 235 animals in four dairy and four beef herds were analyzed. Detection methods used included indirect fluorescent antibody tests of virus-infected cell cultures (BLV, BSV, BVV) and agar gel immunodiffusion (BLV). Sera from the BLV-infected animals in the dairy herds showed the highest single (50%, 49/97) and multiple (30%, 29/97) infections compared with 5% (7/138) and less than 1% (1/138), respectively in the beef herds. Single BVV infections were not detected in the dairy herds, but 11% (11/97) of the sera contained antibodies to BVV plus BLV or BSV. Five sera from beef cattle had antibodies only to BVV and four were obtained from one herd. Only one beef serum of the 138 tested demonstrated multiple antibodies (BLV, BVV).     

猪细小病毒、伪狂犬病病毒和猪圆环病毒2型多重PCR检测方法的建立及应用

根据猪细小病毒(PPV)、伪狂犬病病毒(PRV)和猪圆环病毒2型(PCV-2)的基因序列,分别选取各自的保守区段设计引物,通过反应条件的优化,建立了检测PPV、PRV和PCV-2的多重PCR方法.用建立的方法对采自陕西省部分猪场的286份病料及血样进行检测,从对临床健康猪全血样品中PPV、PRV和PCV-2的检测结果看...