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1.
鸡传染性支气管炎病理形态学及发病机理的研究   总被引:5,自引:1,他引:4  
150只18日龄雏鸡随机分为两组,试验组90只接种传染性支气管炎病毒(IBV-M41)后35天内分30批依次于不同时间扑杀,作组织病理学、超微结构及病毒抗原位检查,对照组60只作相同的检查。结果表明,IBV攻击的靶器官是气管,气管的病变表现为粘膜上皮细胞的损伤和脱、残留的在皮细胞增殖形成复层上皮、粘膜固有层及粘膜下层大量淋巴细胞浸润及粘膜逐渐恢复的相互连续的病理过程。肺脏初级、次级支气管也有类似的  相似文献   

2.
A recombinant DNA probe with specificity for the 3' end of genomic RNA from the Ark 99 strain of infectious bronchitis virus (IBV) was found to hybridize with extracted RNA of three strains with the Ark serotype, as well as the Mass41, Holl52, Gray, JMK, Conn, Fla and SE17 strains of IBV. Viral infection was detected in the cytoplasm of chicken embryo kidney cells inoculated with Mass41, Ark99, SE17 or two recent field isolates of IBV using in situ cytohybridization and a biotinylated probe. In vivo infections were detected in individual cells of tracheas and lungs 2,4, and 6 days after inoculation of chicks with Mass41 and Ark99. In situ hybridization of Ark99 infected tissue sections using 32P-dATP labelled probe indicated that more viral replication was present in the trachea on day 4 than either days 2 or 6; whereas more viral RNA was found in the lungs on day 6 than days 2 or 4 after inoculation.  相似文献   

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Infectious bronchitis (IB) is an economically important viral disease with worldwide distribution. Every country with an intensive poultry industry has infectious bronchitis virus (IBV). The virus rapidly spreads from bird to bird through horizontal transmission by aerosol or ingestion. Sentinel bird studies were carried out in southern Ontario and IBV has been isolated from layer flocks. Genetic analysis of the S1 region of the strains showed that they were not vaccine related. The pathogenicity of selected Ontario variants of IBV isolates was studied and the subsequent work was to determine the degree of protection against field isolates provided by a commonly used vaccine MILDVAC-Ma5 in Ontario. The protection was evaluated by challenging immunized chickens with the respiratory (IBV-ON1) and nephropathogenic (IBV-ON4) viruses. The mean vaccine efficacy for IBV-ON1 was 66.7% indicating that a Massachusetts serotype vaccine would provide some protection against IBV field isolates.  相似文献   

5.
2008年1月,河北沧州某产蛋鸡场鸡群出现呼吸道症状,少数鸡只出现死亡,剖检发现鸡只肾脏肿大,呈“花斑肾”样,收集患病鸡只肾脏、气管等组织,进行病毒分离培养.经新城疫病毒干扰试验、血凝试验、动物回归试验、鸡胚交叉中和试验及分子生物学鉴定,证实分离到一株鸡传染性支气管炎病毒,并命名为0801;鸡胚交叉中和试验结果表明,0...  相似文献   

6.
鸡IBV、NDV和AIV多重RT-PCR检测方法的初步建立   总被引:1,自引:0,他引:1  
根据鸡传染性支气管炎病毒M基因、禽流感病毒NP基因和新城疫病毒F基因各设计1对引物,初步建立了针对鸡传染性支气管炎(IB)、新城疫(ND)和禽流感(AI)的多重RT-PCR鉴别诊断方法,并对其特异性和敏感性进行了检测。结果表明,所设计的3对引物可对同一样品中的IBV、NDV和AIV进行特异性扩增,所扩增的目的片断的长度分别为333bp(IBV)、438bp(NDV)和196bp(AIV);建立的多重RT-PCR检测方法能够检测出1ng/μLAIV、1ng/μLNDV和10ng/μLIBV的cDNA,说明该检测方法特异性强,敏感性较高。本研究所建立的多重RT-PCR方法可用于上述3种鸡病毒性呼吸道疾病的快速鉴别诊断,在临床诊断和流行病学调查方面具有较好的应用前景。  相似文献   

7.
Chicken embryos were inoculated with 8 different strains of infectious bronchitis virus (IBV) representing 7 different serotypes at 17 days of embryonation. At 2 and 5 days postinfection (dpi), tissues were collected for in situ hybridization using an antisense digoxigenin-labeled riboprobe corresponding to the sequence of the mRNA coding for the membrane protein. Extensive antigen staining in the cytoplasm of epithelial cells in the trachea, lung, bursa, and intestine was detected at 2 dpi with all 8 strains of IBV. At 5 dpi, little or no positive staining was observed in these tissues. However, tubular cells of the kidney showed multifocal positive staining with the Wolgemuth strain-, Gray strain-, JMK strain-, and Mass41 strain-infected chickens. No viral RNA was detected in the spleen at any time point. The results demonstrated strict epitheliotropic nature and wide tissue tropism of strains of IBV in the chicken embryo and the universality of our riboprobe. In situ hybridization with this probe will be useful for understanding the tissue tropism and the pathogenesis of IBV in vivo.  相似文献   

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Two experiments were conducted using commercial broiler chickens to determine if Marek's disease (MD) vaccines HVT/SB-1 and HVT plus CVI-988 given either in ovo or at hatch adversely affected the efficacy of infectious bronchitis (IB) vaccines (Ark and Mass serotypes) given by eyedrop on the day of hatch. Nonvaccinated negative controls and controls that received only IB vaccines were included in each study. Birds were challenged with either infectious bronchitis virus (IBV) Mass-41 or IBV Ark-99 on either day 26 or 27 of age. Protection was assessed 5 days post-IBV challenged by virus isolation from the trachea. The day of hatch mean antibody titer to IBV was 12,668 +/- 4704 and 2503 +/- 3243 by enzyme-linked immunosorbent assay in experiments 1 and 2, respectively. In each study, nonvaccinated controls had a significantly higher (P < or = 0.05) incidence (88%-100%) of IBV challenge virus isolation than did controls vaccinated for IB but not for MD. Analysis of data from both studies showed that protection to IB in groups that received only IB vaccines at hatch ranged from 55.0% to 77.3%, whereas protection to IB in groups receiving both MD and IB vaccines ranged from 50.0% to 95.5%. In both experiments and within IBV challenge serotype, broilers given MD vaccines (in ovo or at hatch) and IB vaccines at hatch had protection rates to IBV challenges that were not significantly less (P < or = 0.05) than IB protection rates of groups that received only IB vaccines at hatch. Analysis of these data shows that administration of high-titered MD vaccines either in ovo or at hatch did not affect the efficacy of an IB vaccination (serotypes Ark and Mass) given by eyedrop at hatch.  相似文献   

10.
Four-day-old specific-pathogen-free chickens were inoculated by eyedrop with four different strains (Gray, JMK, CV56b, and Wolgemuth) of infectious bronchitis virus (IBV). Birds were monitored clinically and euthanatized at 1, 4, 7, and 14 days postinfection and tissues were collected for virus isolation, histopathologic examination, in situ hybridization (ISH), and immunohistochemistry (IHC). Clinical disease was severe in chickens infected with Wolgemuth, but no overt disease was observed with the other strains. Virus was isolated from the kidneys of chickens infected with the Gray-, CV56b-, and Wolgemuth-strains of IBV. Histologically, interstitial nephritis was evident in chickens infected with these same 3 strains. However, viral nucleic acid and antigen were detected only with Wolgemuth-infected kidneys by ISH and IHC. These results indicate that the pathological changes in kidneys from chickens infected with Gray and CV56b may not have resulted from the cytolytic action of the virus.  相似文献   

11.
Infectious bronchitis (IB) is a highly contagious viral disease and is responsible for considerable economic losses in the poultry industry, worldwide. To mitigate the IB-associated losses, multiple vaccines are being applied in the sector with variable successes and thus necessitating the development of a potent vaccine to protect against the IB in the poultry. In the present study, we investigated a bivalent live attenuated vaccine consisting of IB virus (IBV) strain H120 (GI-1 lineage) and D274 (GI-12 lineage) to evaluate its protection against heterologous variant of IBV (GI-23 lineage) in chicken. Protection efficacy was evaluated based on the serology, clinical signs, survival rates, tracheal and kidney histopathology and the viral shedding. Results demonstrated that administering live H120 and D274 (named here Classivar®) vaccine in one day-old and 14 days-old provided 100 % protection. We observed a significant increase in the mean antibody titers, reduced virus shedding, and ameliorated histopathology lesions compared to routinely used vaccination regimes. These results revealed that usage of different IBV vaccines combination can successfully ameliorate the clinical outcome and pathology in vaccinated chicks especially after booster vaccination regime using Classivar®. In conclusions, our data indicate that Classivar® vaccine is safe in chicks and may serve as an effective vaccine against the threat posed by commonly circulating IBV strains in the poultry industry.  相似文献   

12.
Three virus isolates (ECV-1, -2, and -3) recovered from cloacae of chickens in flocks that experienced drops in egg production were identified as infectious bronchitis virus (IBV), based on characteristic embryo lesions, chloroform sensitivity, coronavirus morphology, and serology. Because these isolates were recovered from the cloacae of the hens, their tissue tropism was compared with the prototype strain of IBV, Massachusetts-41 (M-41), in experimentally inoculated chickens. During the 39-day period postinoculation (PI), virus isolation was attempted from digestive and respiratory tracts, kidney, and cloacal swabs. ECV-1, ECV-2, and M-41 were more frequently recovered from the cecal tonsils than from other tissues. ECV-1, ECV-3, and M-41 were also recovered from kidney for up to 39 days PI. ECV-2 and ECV-3 had a limited distribution in respiratory tissues, being isolated only sporadically from trachea, bronchus, and lung. Surprisingly, ECV-2 was isolated from esophagus at 2, 16, 30, and 39 days PI; otherwise, its distribution in other tissues was sporadic. Results confirmed that IBV, including M-41, can infect a variety of tissues and that some isolates may be recovered frequently from digestive tract tissues, particularly from the cecal tonsils.  相似文献   

13.
【目的】探究呼吸型传染性支气管炎病毒(Infectious bronchitis virus,IBV)对蛋鸡免疫反应的影响及重组禽β-防御素(avian β-defensins,AvBDs)的抗病毒作用。【方法】试验将70只7日龄SPF白来航鸡随机分为2组,每组35只。攻毒组通过滴鼻点眼途径接种呼吸型IBV强毒(CK/CH/LSD/05I),对照组以相同途径接种等剂量灭菌PBS。定时观察临床症状14 d并记录,在攻毒后12 h、36 h、3 d、7 d和14 d 2组各随机选取5只鸡心脏采血处死,检测血清抗体水平并收集部分气管和肾脏进行组织病理学检测。采集法氏囊、脾脏、肾脏和气管,提取RNA,运用实时荧光定量PCR方法检测组织中IBV的病毒载量、Toll样受体(Toll-like receptors,TLRs)及信号转导分子、AvBDs基因表达量变化。将重组AvBD11和AvBD12转染鸡胚肾细胞(chicken embryo kidney,CEK)并在病毒感染细胞后6、12、24、36和48 h收取细胞上清和细胞用于提取RNA,通过实时荧光定量PCR方法检测病毒载量。【结果】感染呼吸型IBV强毒后,鸡出现轻微呼吸道症状,剖检无明显病理变化。在感染14 d后,鸡血清抗体水平转阳且阳性率为100%。实时荧光定量PCR结果显示,对照组均未检测到病毒,攻毒组仅在感染14 d后的气管中检测到病毒且病毒载量低。与对照组相比,攻毒组脾脏中TLR1、TLR5、AvBD9和AvBD12基因表达量在感染后7 d均显著升高(P<0.05),攻毒组法氏囊中TLR1、TLR2、TLR3、AvBD5和AvBD9基因表达量及气管中核转录因子-κB p65(NF-κB p65)、NF-κB c-Rel、AvBD5、AvBD9、AvBD11和AvBD13基因表达量在感染14 d后均显著升高(P<0.05)。体外抗病毒结果显示,与转染空载体组相比,转染AvBD11的CEK细胞在感染24和48 h后病毒载量显著下调(P<0.05),细胞上清的病毒载量在感染48 h后显著下调(P<0.05);转染AvBD12的CEK细胞在感染12和24 h后病毒载量显著下调(P<0.05),细胞上清的病毒载量在感染12和48 h后显著下调(P<0.05),说明重组AvBD11和AvBD12在CEK细胞中具有抗IBV活性。【结论】呼吸型IBV强毒感染机体后增强了相关受体的基因表达和信号转导,上调了AvBDs基因表达,加强了机体免疫反应。重组AvBD11和AvBD12具有抗病毒作用,为无抗饲料的配制及研究提供了新思路。  相似文献   

14.
禽副粘病毒2型(PMV-2)致病性的研究   总被引:1,自引:0,他引:1  
7日龄SPF鸡经滴鼻、点眼感染PMV-2,可引起轻微的呼吸道症状,病理组织学观察可见气管粘液分泌亢进和少量的淋巴细胞浸润。PMV-2与传染性支气管炎(IBV)或鸡毒支原体(MG)协同感染比单纯感染这三种病原的任何一种均呈现更严重的呼吸道症状,病理组织变化呈气管纤毛部分或全部脱落,气管粘膜上皮细胞不同程度的变性、脱落。固有层和粘膜下层严重水肿,有大量淋巴细胞、巨噬细胞和异嗜细胞浸润。SPF雏鸡感染PMV-2后的不同时间检查病毒在鸡体内的分布规律,结果表明,PMV-2在法氏囊中大量分布;气管、肺、胸腺中有较多病毒;大脑、脾和肾脏只有少量病毒存在。上述实验结果揭示PMV-2感染SPF雏鸡致病性较弱,PMV-2在鸡呼吸道综合征中起一定作用。  相似文献   

15.
参考 Gen Bank上的传染性支气管炎病毒 (IBV)序列 ,自行设计合成了 3条引物 ,对 IBV青岛腺胃分离株 (SD/97/ 0 2 ) RNA进行 RT- PCR扩增 ,扩增含基质蛋白 (M)及 5 a、5 b蛋白基因的约 1.6 5 kb的片段 ,对 PCR产物进行克隆后测序。序列分析显示 ,M蛋白基因与其他 IBV相应的基因同源性在 90 .33%~ 92 .75 %之间 ,氨基酸序列比较 ,同源性在 89.82 %~ 94.2 5 %之间 ;5 a基因与其他 IBV的基因同源性在 84.34 %~ 87.37%之间 ,氨基酸同源性在 81%~82 %;5 b基因与其他 IBV的基因同源性在 91%~ 92 %之间 ,氨基酸同源性在 93%左右。  相似文献   

16.
鸡传染性支气管炎病毒免疫机制和免疫预防研究进展   总被引:1,自引:0,他引:1  
由鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV)引起的鸡传染性支气管炎(Infectious bronchitis,IB)是高度传染的全球性鸡病之一,严重危害养鸡业。IBV众多的血清型及其基因组的不断变异,给IB的免疫防控带来很大的困难。IBV主要侵害鸡的呼吸系统、泌尿生殖系统和消化系统,病鸡出现呼吸困难、产蛋下降、肾炎和腺胃炎等症状和病变。IBV的特点是变异频繁,血清型复杂,所致疾病的临床表现差异很大。因此,IB已成为养禽业最难控制的疫病之一。鸡对IBV的免疫机制是国内外研究的热点之一。传统疫苗已不能完全保护免疫鸡群,开发IBV基因工程疫苗,从主要免疫原性蛋白的良好表达到免疫策略的不断完善,已成为未来预防IB的趋势。  相似文献   

17.
鸡传染性贫血疫苗免疫母鸡后子代雏鸡的免疫学变化   总被引:1,自引:0,他引:1  
应用免疫学新技术对鸡传染性贫血(CIA)疫苗免疫母鸡后,其子代雏鸡外周血液和免疫器官组织及局部体液的免疫学变化进行了动态研究。结果表明:CIA疫苗免疫母鸡后,其子代雏鸡外周血液T、B细胞数量和IgG、IgM、IgA含量及免疫器官组织的T细胞和IgG、IgM、IgA抗体生成细胞以及泪液、气管液、胆汁、肠液的IgA、IgM、IgG含量均不同程度地高于未免疫的相应对照雏鸡,表明CIA疫苗免疫母鸡后,其子代雏鸡全身的体液免疫和细胞免疫功能明显增强。而CIAV强毒攻击后,未免疫的子代雏鸡,其外周血液和免疫器官组织及局部体液的上述各项指标均明显低于疫苗免疫的子代雏鸡。  相似文献   

18.
Tissues were obtained at necropsy from the nasal vestibule, turbinates, nasopharynx, trachea, tracheobronchial bifurcation, and lung from each of 10 clinically healthy calves persistently infected (PI) with bovine viral diarrhea virus (BVDV) serotype 2a. Tissues from the nasal vestibule were obtained by biopsy from five additional PI calves. Formalin-fixed tissues were processed for immunohistochemistry to localize the distribution of BVDV throughout the respiratory tract. Antigen distribution and intensity were subjectively evaluated. Throughout the respiratory tract, mononuclear leukocytes, vascular smooth muscle, and endoneural and perineural cells had BVDV immunoreactivity (BVDV-IR). Multifocally, squamous and ciliated columnar epithelium throughout the respiratory tract contained weak to moderate BVDV antigen. Viral antigen was not seen in goblet cells. BVDV-IR in mixed tubuloalveolar glands of the nasal cavity was weak to strong in serous secretory cells and ductular epithelium. Chondrocytes of the concha often contained BVDV antigen diffusely. Nasal mucus-secreting and tracheobronchial glands multifocally contained weak viral signal. In all cases, alveolar macrophages had moderate to strong BVDV-IR, whereas BVDV-IR in alveolar epithelial cells was weak to moderate. BVDV was present in interalveolar leukocytes and mesenchymal cells. Results indicate that serous secretions of the nasal cavity, productive viral infection of epithelium, and infected leukocytes in respiratory secretions are likely major sources of infectious BVDV from PI calves. The presence of BVDV antigen in respiratory epithelium is, at least, indirect support for the notion that this virus predisposes PI cattle to secondary microbial infections.  相似文献   

19.
Enzootic bronchopneumonia (EBP) is an infectious, multifactorial respiratory disease of cattle. Different viruses may be involved in its pathogenesis. In this study an adapted method of endoscopic bronchoalveolar lavage (BAL) of caudal parts of the right cranial lung lobe was established and evaluated. The obtained bronchoalveolar lavage fluid (BALF) served as template for the detection of BRSV, BPIV-3 and BCoV specific nucleic acids by RT-PCR. BALF samples of 44 cattle affected with respiratory disease were compared to nasal swabs in their reliability to detect the causative agent(s). In 6/7 animals tested positive for BRSV, RNA of this virus was detected in the BALF, in 4 animals it could be found in the nasal swabs. In two of the three BPIV-3 positive animals, the BALF was the only material that tested positive. The most reliable samples for detection of 15 BCoV positive animals were the nasal swabs. BAL was easy to perform, it led to severe coughing in one case and moderate worsening of dyspnoe in three cases. In conclusion this study shows that BAL of the right cranial lung lobe is in many cases the only tool to detect BRSV and BPIV-3, major viral triggers of EBP.  相似文献   

20.
鸡感染传染性支气管炎病毒后脏器内病毒动态分布研究   总被引:1,自引:1,他引:0  
对IBV在鸡器官内动态分布进行了初步研究。分别用IBV T株、M41、H52、H120、上海野毒(Sh1、Sh2、Sh3)对7个试验组的鸡攻毒,分别用AIV、NDV以及IBDV对3个对照组鸡攻毒,然后定期剖杀采样,并用套式RT-PCR方法进行检测。结果为攻毒后第3天和第7天,7个IBV攻毒组的肾脏、气管、肝脏、肺脏和扁桃体中均检测到IBV;第14天,H52组、H120组肝脏、扁桃体IBV检测阴性,其余脏器均为阳性,其他组5个脏器均为阳性;第21天,M41组、H52组、H120组肾脏、肝脏、扁桃体检测阴性,其余为阳性,其他组5个脏器全为阳性;第28天,M41组、T组、H52组、H120组、Sh1组肾脏、肝脏、扁桃体以及T组的肝脏和扁桃体为阴性,其余脏器为阳性,其他组5个脏器仍为阳性;35 d后,各实验组各脏器均为阴性。整个试验阶段,对照组的IBV检测均为阴性。由此可见,IBV不同毒株组织嗜性存在明显差异,导致IBV各毒株在感染鸡体内的分布和消长规律存在着差异。这为阐明IBV致病机理提供了必要的试验依据。  相似文献   

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