鸡传染性贫血病毒感染胸腺集落刺激因子对骨髓粒单系祖细胞增殖功能的影响

本文研究了鸡传染性贫血病毒感染鸡胸腺ＣＳＦ对正常鸡骨髓粒单系祖细胞（ＣＦＵ—ＧＭ）增殖功能的影响．结果表明，雏鸡感染ＣＩＡＶ后１４天胸腺ＣＳＦ对ＣＦＵ—ＧＭ刺激作用与对照鸡比较未见明显异常．感染后２１天，刺激作用较对照鸡明显增强（ｐ＜０．０１）；感染２８天以后，其刺激作用达正常成水平．结果证明，ＣＩＡＶ感染引起的骨髓造血机能障碍与胸腺ＣＳＦ活性无关．     

应用PCR从AA肉种鸡鸡胚和1日龄雏鸡体内检测出CIAV和ALV-J

为了了解鸡传染性贫血病病毒（CIAV）和J亚群禽白血病病毒（ALV-J）对AA肉种鸡鸡胚和1日龄雏鸡的感染情况,试验直接从山东省3个不同AA肉种鸡场的鸡胚和1日龄雏鸡的肝、脾、肾、胸腺、骨髓、法氏囊等组织（器官）提取DNA,进行了PCR扩增及PCR产物的克隆和序列测定。结果显示,被检的3个肉种鸡场的鸡胚和1日龄雏鸡体内均有这2种病毒核酸的检出,其中CIAV的阳性率是20.42%,ALV-J的阳性率是15.83%,二者共感染的阳性率是6.25%;在阳性检出率中弱雏〉死胚〉健康雏〉正常胚。病毒核酸在各感染组织（器官）的含量也有所差异,CIAV以脾的含量最多,ALV-J以肾的含量最多。对肝进行细菌分离鉴定时发现,3个鸡场还存在大肠杆菌、沙门氏菌和霉形体的混合感染。结果提示,在AA肉种鸡鸡胚和雏鸡体内存在CIAV、ALV-J的感染和二者的共感染以及继发性大肠杆菌、沙门氏菌和霉形体的混合感染。     

感染鸡传染性贫血病毒（CIAV）雏鸡免疫器官抗体生成细胞的动态变化

对１日龄雏鸡感染鸡传染性贫血病毒（ＣＩＡＶ）后免疫器官法氏囊、脾脏和胸腺的ＩｇＧ、ＩｇＭ、ＩｇＡ抗体生成细胞数量的动态变化进行了检测。结果发现,感染雏鸡法氏囊、脾脏和胸腺的３种抗体生成细胞数量均程度不同地低于未感染对照雏鸡,其中法氏囊的ＩｇＧ、ＩｇＭ抗体生成细胞和ＩｇＡ抗体生成细胞分别在感染后７～３５ｄ和１４～３５ｄ明显减少;脾脏红髓、白髓和淋巴小结的ＩｇＧ抗体生成细胞分别于７～３５ｄ、１４～３５ｄ和１４～２１ｄ明显减少,ＩｇＭ抗体生成细胞分别在７～４２ｄ、２８～３５ｄ和１４ｄ时明显减少,ＩｇＡ抗体生成细胞仅在红髓中（７～２８ｄ）明显减少;胸腺髓质的ＩｇＧ、ＩｇＭ、ＩｇＡ抗体生成细胞分别在１４～２８ｄ、７～２１ｄ和２１ｄ时明显减少。结果表明,ＣＩＡＶ感染雏鸡免疫器官的体液免疫功能明显降低。     

鸡贫血病毒实验感染雏鸡胸腺与骨髓的超微结构观察

用鸡贫血病毒 Ｃｕｘ １ 毒株接种于 １ 日龄 Ｓ Ｐ Ｆ 雏鸡，在确认感染成功的基础上，对感染雏鸡胸腺和骨髓的超微结构进行了观察。电镜观察表明，感染鸡骨髓和胸腺细胞的形态变化具有较典型的凋亡特征，如细胞膜出泡、核染色质凝结边集、细胞核裂解、出现凋亡小体等，此外还见有可能由病毒粒子形成的环状物。本试验为证明鸡贫血病毒能引起细胞凋亡提供了依据。     

鸭源鸡杆菌对SPF雏鸡的感染特性研究

为研究鸭源鸡杆菌的流行病学特性,本研究采用从自然病例分离得到的鸭源鸡杆菌人工感染4日龄SPF雏鸡,通过形态学、PCR、荧光定量PCR和组织学等方法分别对感染后SPF雏鸡的组织脏器进行了细菌分离、检测和鉴定,用ELISA对其血清抗体水平进行检测.结果表明,人工感染鸡无临床症状,组织学检查感染鸡的肝脏、气管和肺脏组织均有损伤.人工感染后第3d和同居感染第2d鸡体内可分离出鸭源鸡杆菌,人工感染后第96d仍能够分离到鸡杆菌.ELISA方法证实人工感染后47 d和同居后32 d出现抗体高峰,持续2～3周,人工感染组和同居组抗体水平均高于对照组(p＜0.05);荧光定量PCR检测病料结果显示人工感染组和同居组的气管组织中细菌含量最高.本研究表明雏鸡在4日龄即可感染鸭源鸡杆菌,并能通过同居传播,长期带菌、排菌;感染后抗体产生缓慢、持续期短.本研究为鸭源鸡杆菌的流行病学、致病机理研究及防治措施的制定等提供了参考依据.     

鸡传染性法氏囊病超强毒感染后SPF鸡免疫器官病理学观察

IBDV超强毒株LX株接种2周龄SPF雏鸡后，其致病性不同于经典强毒株CJ801株，它主要引起接种鸡全身性炎症反应，法氏囊、脾脏、盲肠扁桃体等免疫器官中大量异嗜性白细胞、巨噬细胞浸润，淋巴细胞严重坏死崩解，胸腺皮质严重萎缩、坏死，骨髓中造血细胞减少、巨噬细胞和脂肪细胞增生。在接种后14d法氏囊淋巴滤泡严重萎缩、淋巴细胞排空形成囊腺样结构，未见恢复正常，其它免疫器官形态基本恢复正常。电镜观察，接种后2和4d可见胸腺淋巴细胞胞浆浓集、染色质周边化形成新月形，表现细胞凋亡特征；在法氏囊坏死淋巴细胞胞浆中可见60nm大小呈晶格排列或散在的病毒粒子。研究初步探明了鸡传染性法氏囊病病毒超强毒的致病机理。     

感染CIAV雏鸡免疫器官对ND疫苗的细胞免疫应答

对１日龄感染ＣＩＡＶ雏鸡接种ＮＤ疫苗后，其免疫器官组织Ｔ细胞数量的动态变化进行研究．结果，感染ＣＩＡＶ雏鸡ＮＤ疫苗免疫局，其胸腺和脾脏以及盲肠扁桃体和哈德尔腺的Ｔ细胞数量，于接种ＮＤ疫苗后较未感染ＣＩＡＶ免疫对照雏鸡明显减少，表明感染雏鸡的中枢和外周免疫器官及局部免疫组织对ＮＤ疫苗的细胞免疫应答功能明显降低．ＮＤ强毒攻击后，感染免疫鸡的免疫保护率明显低于未感染免疫对照鸡．     

一株鸡传染性贫血病毒对不同日龄SPF鸡的致病性研究

为评价鸡传染性贫血病毒AV1550株的致病性,取1日龄、7日龄和14日龄SPF鸡分别经胸部肌肉注射不同病毒含量的病毒液,同时设置正常对照,隔离饲养观察21日。感染后14日采血测定红细胞压积,21日统计死亡率、体重变化以及胸腺、骨髓、法氏囊病变情况并测定1日龄SPF鸡感染后不同组织中的病毒载量。结果表明,1日龄SPF鸡感染AV1550株后,表现出精神沉郁、增重减缓、贫血等明显的临床症状,死亡率为53.9%;死亡鸡或观察期结束时存活鸡剖检,可见胸腺萎缩,骨髓变成淡黄色;不同剂量感染后14日,均能引起红细胞压积显著下降;21日时,胸腺病毒载量最高,可达106.7copies/mg 。7日龄SPF鸡感染后,出现增重减缓,高感染剂量（100000EID50）出现贫血,部分鸡出现胸腺萎缩和骨髓病变,但病变率低于30%。14日龄SPF鸡感染后,不引起明显临床症状。研究证实,CAV对SPF鸡的致病性具有明显的日龄依赖性,红细胞压积降低、骨髓病变、胸腺萎缩以及胸腺病毒载量测定可作为评价CAV致病的指标。     

鸡传染性贫血病毒感染对雏鸡免疫系统的影响Ⅱ．几种细胞因子体外诱生活性动态变化

１日龄雏鸡人工感染鸡传染性贫血病毒（ＣＩＡＶ）后７、１４ｄ，脾脏Ｔ淋巴细胞ＩＬ－２活性明显降低（Ｐ＜０．０１，Ｐ＜０．０５），２１ｄ明显回升，２８ｄ显著升高（Ｐ＜０．０５），３５ｄ后降至对照水平；感染后７、１４和２１ｄ，胸腺Ｔ淋巴细胞ＩＬ－２诱生活性明显降低（Ｐ＜０．０５），２８ｄ后恢复至对照水平。感染后７、１４ｄ，脾脏淋巴细胞ＩＦＮ诱生活性明显低于对照鸡（Ｐ＜０．０５），２１ｄ后恢复至对照水平。感染后１４ｄ，胸腺淋巴细胞集落刺激因子（ＣＳＦ）诱生活性未见明显变化，２１ｄ显著升高（Ｐ＜０．０５），２８ｄ降至正常水平。     

Isolation and identification of chicken infectious anemia virus in Brazil.

Seven chicken infectious anemia virus (CIAV) isolates were obtained from seven broiler flocks with poor performance in two states of Brazil. All isolates induced thymus atrophy, bone-marrow aplasia, and low hematocrit values when inoculated into 1-day-old susceptible chicks. The CIAV isolates were resistant to treatment with chloroform and were able to pass through 50-nm-pore-size filters. CIAV-specific antigens could be demonstrated in tissues of experimentally infected chicks using a monoclonal antibody specific for CIAV. These characteristics of the virus and the virus-induced lesions demonstrate that CIAV is present in Brazil and that the virus is associated with production problems.     

A clinical case of chicken infectious anemia disease and virus DNA detection in naturally infected broilers in Greece

In this study, chicken infectious anemia virus (CIAV) DNA was detected from 12-day-old broilers. Clinical history showed that the clinical features were diarrhea, blue wing disease, depression, and death. Necropsy findings were pale liver, severe atrophy of bursa of Fabricius and thymus, and discoloration of the bone marrow as well as hemorrhages subcutaneously and a few in skeletal muscles. The majority of the necropsied broilers had developed gangrenous dermatitis. Histopathology showed hypoplasia of bone marrow and depletion of lymphocytes in spleen, bursa, and subcapsular thymic cortex. Karyorrhexis of lymphocytes was scattered in the thymic cortex and most pronounced in the bursal follicles. Eosinophilic intranuclear inclusion bodies were mainly located in lymphocytes of thymus, with a few in hemopoietic cells of bone marrow. CIAV DNA was detected by polymerase chain reaction from bursa, thymus, and bone marrow. A virus strain was detected and genetically characterized in 639 base pairs of VP1 gene. Phylogenetic analysis revealed that the Greek isolate was clustered together with isolates from Alabama, China, Slovenia, and Bangladesh.     

Experimental bovine coronavirus in turkey poults and young chickens

The DB2 calf strain of bovine coronavirus (BCV) was used to inoculate 1-day-old specific-pathogen-free (SPF) turkey poults in three trials. In all trials, the birds developed clinical signs of enteritis at 48-72 hr postinoculation. Birds euthanatized at 3, 5, and 7 days postinoculation (DPI) had flaccid, pale intestines with watery contents, and the ceca were markedly enlarged with frothy contents. Coronavirus particles were detected by immune electron microscopy with BCV antibodies from the intestinal contents of birds killed at 3, 5, 7, and 12 DPI. Body weights of inoculated poults killed at 3, 5, and 7 DPI were significantly reduced as compared with controls. Hemagglutinating antibodies were detected in sera of convalescent birds at 12 DPI. However, experimental inoculation of 1-day-old SPF chicks in two trials with the same virus resulted in no clinical signs or macroscopic or microscopic lesions. No coronaviruses were detected from intestinal contents, and there were no significant differences in body weights of inoculated and noninoculated control chicks.     

Immunopathologic investigations with an attenuated chicken anemia virus in day-old chickens

The immunopathologic effects induced by two attenuated chicken anemia virus (CAV) isolates, known as cloned isolate 34 (CI 34) and cloned revertant isolate 18 (CRI 18), that were derived from highly passaged pools of Cux-1 CAV isolate, were compared with those induced by a pathogenic, molecularly cloned, low-passage Cux-1 isolate (CI Cux). This comparison involved the intramuscular inoculation of 1-day-old specific-pathogen-free chicks with each of the viruses and investigation of birds at selected days postinoculation for gross pathology and depletions in the thymic T-cell populations as determined by flow cytometry. Whereas infection with the pathogenic CI Cux produced severe anemia and pronounced bone marrow and thymus lesions, infections with the attenuated CRI 18 and CI 34 isolates produced no anemia, no or mild lesions, respectively, and moderate T-cell depletion. The results suggest that, with CAV, reduced pathogenicity for 1-day-old chicks correlates with reduced depletion of T-cell populations in the thymus and with reduced severity of lesions in the thymus and bone marrow.     

鸡贫血病—法氏囊病联合免疫母鸡后子代雏鸡免疫器官T细胞和抗体生成细胞数量的动态变化

对鸡传染性贫血病（CIA）－传染性法氏囊病（IBD）联合免疫母鸡后的子代雏鸡免疫器官的免疫学化变化进行了研究。结果发现,混合感染CIAV、IBDV雏鸡免疫器官T细胞和IgG,IgM,IgA抗体生成细胞数量在27日龄内明显未免疫对照组、联合免疫组和联合免疫攻毒组,表明感染CIAV、IBDV的雏鸡全身免疫功能显著下降,CAI－IBD联合免疫母鸡后,子代雏鸡T细胞胞和IgG,IgM,IgA抗体生成细胞数量在27日龄内,较未免疫对照组明显增加,表明CIA－IBD联合免疫母鸡可使子代雏鸡免疫器官的免疫功能增强,能抵御强毒攻击。     

鸡传染性贫血病疫苗免疫母鸡后子代雏鸡外周血液T细胞数量及免疫球蛋白含量变化

应用免疫SPA菌体不法和间接ELISE法对鸡传染性贫血病（CIA）疫苗免疫母鸡后，其子代雏鸡外周血液T细胞数量和血清IgG,IgM,IgA含量进行了动态研究。结果发现：CIA疫苗免疫母鸡后，其子代雏鸡外周血液T细胞数量和IgG,IgM,IgA含量均不同和蔼地高于未免疫的相对照雏鸡，表明CIA疫苗免疫母后，其子代雏鸡全身的体液上述各项指标均明显低于疫苗免疫的子代雏鸡，这与CIAV强毒攻击子代雏鸡后，未免疫的子代雏鸡外周血液上述各项指标均明显低于疫苗免疫的子代雏鸡，这与CIAV强毒感染雏鸡后，其免疫器官组织，尤其是胸腺严重损害，淋巴细胞变性坏死子等密切相关，是导致感染鸡免疫功能低下的基础。     

Crop immune response post-Salmonella enteritidis challenge in eight commercial egg-layer strains and specific-pathogen-free White Leghorn chickens

The crop immune response against Salmonella Enteritidis (SE) challenge in eight commercial egg-layer strains (five white-egg layer and three brown-egg layer) and specific-pathogen-free (SPF) White Leghorn (WL) hens was investigated. Pre- and post-SE challenge mucosal immune responses within the crops were evaluated. Commercial layers and SPF WL hens were orally challenged with 10(8) CFU/ml SE PT13a and SE nalR PT13, respectively. Crop lavage samples were collected at weekly intervals from day 0 (pre-challenge) to day 25-27 postinfection (PI), and bacteriological examination was performed to monitor progression of SE infection. Crop lavage samples were analyzed for SE-lipopolysaccharide (LPS)-specific IgA using enzyme-linked immunosorbent assay (ELISA). H&E-stained slides of crop sections from day 34 PI and uninfected controls were assessed for lymphoid tissue via light microscopy. Lymphoid areas were graded based on morphology, size, and cellularity using a score 0 to 5 scale. The 0 to 5 (low to high) numerical values represented progressive increases in size and cellular density of lymphoid tissue. Bacterial culture results showed the highest percentage of SE-positive crop lavage samples from all hen groups at day 5-6 PI and day 11-12 PI. A progressive decline in percentage of SE-positive crop lavage samples did occur as time PI lengthened; however, at day 25-27 PI SE persisted in crop lavage samples from SPF WL hens and three commercial white-egg layer strains. A marked increase in SE-LPS-specific IgA was measured in crop lavage samples between day 0 and day 11-12 PI for all hen groups. Crop SE-LPS-specific IgA response remained elevated above day 0 baseline for the duration of the experiment. Well-defined score 3 to 5 lymphoid tissue aggregates were observed in crop tissue sections harvested at day 34 PI. Comparison of crop sections determined a 1.2-4.0 times increase in ratio of lymphoid tissue in day 34 PI SE-challenged hens vs. uninfected control hens.     

LTR对J亚群禽白血病病毒感染的影响

为探讨LTR基因在骨髓瘤病变型J亚群禽白血病病毒(ALV-J) NX0101致病中的作用,利用反向遗传将血管瘤病变型ALV-J HN06株中两端LTR元件替换至NX0101株的相应位置,拯救出重组病毒NX-HNLTR株.人工接种7日龄SPF雏鸡,分别检测NX0101株和NX-HNLTR株对鸡体的影响.感染鸡生长都较慢.感染NX0101株的鸡,胸腺指数和腔上囊指数明显比对照组低,脾脏指数与对照组相比波动较大,骨髓和脾脏在攻毒后3周可检测到病毒整合到基因组中,胸腺和腔上囊在攻毒后6周才检测到.感染NX-HNLTR株的鸡脾脏指数明显比对照组低,攻毒后2周可检测到病毒整合到脾脏基因组中,骨髓和胸腺分别在攻毒后3周和6周检测到.结果提示,LTR对NX0101株感染鸡的免疫器官有一定的影响.     

鸡实验性成髓细胞性白血病的细胞化学及超微结构

用鸡成髓细胞性白血病病毒（ＡＭＶ）ＢＡＪ－Ａ株鸡传代血浆毒感染１日龄伊莎鸡雏２０只，在接毒后１９￣２５ｄ于濒死期扑杀、采样，进行细胞化学和电镜检查。结果表明，肝、肾、法氏囊、胸腺及血液的成髓细胞来源于骨髓；其成髓细胞胞浆、胞膜及细胞间隙存在带有囊膜的含核心的病毒粒子。     

Detection of chicken anemia virus DNA in embryonal tissues and eggshell membranes

Chicken infectious anemia virus (CIAV) is a ubiquitous and highly resistant virus of chickens that causes anemia and death in chicks less than 3 wk of age and immunosuppression in chickens older than 3 wk of age. The production of specific-pathogen-free eggs free of CIAV is essential for research and vaccine production. Currently, flocks are screened for CIAV by antibody tests to ensure freedom from CIAV infection. Recent evidence, however, indicates that chickens may carry and vertically transmit CIAV DNA independently of their antibody status. In this study, we tested embryos and eggshell membrane residues by nested polymerase chain reaction (PCR) as a sensitive method of detecting CIAV DNA. CIAV DNA could be detected in the blastodisks and semen obtained from antibody-positive and -negative chickens. Examination of different tissues between 18 and 20 days of incubation indicated that many but not all organs of individual embryos were positive. The lymphoid organs and gonads had the highest incidence of CIAV DNA, which was significantly different (P < 0.05) from the incidence in the liver. Eggshell membrane samples from embryos or newly hatched chicks were an excellent noninvasive source for the detection of CIAV DNA, identifying significantly more positive embryos than did pooled lymphoid organs. The use of dexamethasone injections as a method to improve the detection of carrier birds did not result in an increase of vertical transmission or cause seroconversion in the treated hens. A combination of testing eggshell membrane residues at hatch and periodic testing of blood DNA by nested PCR can be used to identify chickens carrying CIAV DNA and may be used to eradicate carrier birds.