鸡4种病毒抗原液的浓缩及其四联油佐剂灭活苗的研制

本研究通过超滤浓缩技术对鸡新城疫病毒、传染性支气管炎病毒、产蛋下降综合征病毒和传染性法氏囊病病毒的尿囊液进行了10倍或10倍以上的浓缩处理，并按一定的比例配比研制成四联油乳剂灭活疫苗，对鸡的最小免疫剂量是0.25ml，免疫接种二周后，鸡新城疫和产蛋下降综合征病毒的HI抗体效价分别达到8log     

Survey of the health and husbandry of small poultry flocks in Great Britain

An investigation into the health and husbandry of 15 small poultry flocks was undertaken. Each flock was visited in July and a questionnaire on management practices and disease history was completed. The flocks were clinically examined and serological tests for Salmonella pullorum, Mycoplasma gallisepticum, M synoviae, M meleagridis, Newcastle disease, infectious bursal disease, infectious bronchitis, eggdrop syndrome 76, adenoviruses and reoviruses were carried out. Oesophageal and cloacal swabs were cultured for mycoplasma and pullorum reactors were cultured. M gallisepticum, M synoviae, M meleagridis and M gallinarum infections were detected and serological reactions for all the viral diseases, except egg drop syndrome 76, were found. Evidence of Newcastle disease and pullorum disease was encountered. Lice were present in five flocks and mites in four flocks. Welfare standards varied.     

鸡传染性喉气管炎病毒PCR诊断方法的建立与应用

根据GenBank登录的传染性喉气管炎病毒(ILTV)的TK基因序列设计并合成1对特异性引物,以ILTV疫苗株DNA为模板,建立了检测ILTV TK基因的PCR方法。应用该方法能从临床分离毒株和疫苗株中扩增到长为427 bp的目的片段;但不能从新城疫病毒(NDV)、传染性法氏囊病毒(IBDV)、禽呼肠孤病毒(ARV)、减蛋综合征病毒(EDSV)、H9亚型禽流感病毒(H9-AIV)、传染性支气管炎病毒(IBV)、大肠杆菌以及金黄色葡萄球菌等病原中扩增出阳性条带;敏感性试验表明其DNA最小检出量为4.9 ng;应用该方法和病毒分离法对2份临床病例和人工感染鸡的检测,两者符合率为100%。上述结果表明该PCR方法具有良好的特异性和敏感性,可用于传染性喉气管炎病毒鉴定和临床诊断。     

鸡传染性支气管炎病毒分型与诊断防治的研究进展

鸡传染性支气管炎是由鸡传染性支气管炎病毒引起的一种急性、高度接触性传染性疾病。以张口呼吸、气管啰音、咳嗽、肾脏病变为主要临床症状,可引起鸡的饲料报酬率降低,蛋鸡产蛋数量和蛋的品质下降。IBV的特点是高频变异,血清型众多,导致疾病的临床和病理变化复杂多样,由于其变异株出现比较快,毒株之间交叉保护力差,给IB的诊断和防治带来了较大困难。从IBV的分型、检测技术、综合防治方面对该病的研究进展进行了综述。     

Emergence of novel strains of avian infectious bronchitis virus in Sweden

Infectious bronchitis virus (IBV) causes avian infectious bronchitis, an important disease that produces severe economic losses in the poultry industry worldwide. Recent IBV infections in Sweden have been associated with poor growth in broilers, drop in egg production and thin egg shells in layers. The complete spike gene of selected isolates from IBV cases was amplified and sequenced using conventional RT-PCR. Nucleotide and amino acid sequence comparisons have shown that the recent isolates bear 98.97% genetic similarity with strains of the QX-like genotype. The phylogenetic analysis revealed that strains predominant in the nineties, which were of the Massachusetts type, have been replaced by D388/QX-like strains, however the evolutionary link could not be established. The homology between the two genotypes was 79 and 81%. Remarkably, a strong positive selection pressure was determined, mostly involving the S1 subunit of the S gene. This strong selective pressure resulted in recombination events, insertions and deletions in the S gene. Two new isolates generated from recombination were found with nucleotide sequence diverging 1.7-2.4% from the D388/QX-like branch, indicating the emergence of a new lineage. The study demonstrates a constant evolution of IBV that might be in relation to increased poultry farming, trade and vaccine pressure. The findings underscore the importance of continuous monitoring to control spread of infections, as well as to timely adjust diagnostic methods, molecular epidemiological studies, development and use of vaccines that are adapted to the changing disease scenario.     

Dot-ELISA检测H9亚型禽流感病毒的研究

本研究采用兔抗H9亚型禽流感病毒（AIV）IgG包被于硝酸纤维素膜,酶标羊抗兔IgG作二抗,建立检测H9亚型AIV的Dot-ELISA法。经方阵试验确定兔抗AIV IgG工作浓度为1∶400,酶标羊抗兔IgG的工作浓度为1∶400。作者建立的Dot-ELISA对AIV的最小检测量为3.35×10-9g。Dot-ELISA与HA和HI、AGP及病毒分离法相比,检测63份临床疑似H9亚型AIV病料,Dot-ELISA检出32份(57.14%),HA和HI检出15份(23.81%),AGP检出11份(17.46%),病毒分离检出38份(60.30%)。用抗H9亚型AIV阳性血清可以阻断Dot-ELISA阳性反应,诊断膜片与鸡新城疫病毒、鸡传染性法氏囊病病毒、鸡传染性支气管炎病毒、产蛋下降综合征病毒不出现阳性反应,证明Dot-ELISA特异性好。分别置室温(25 ℃左右)、4 ℃和-20 ℃下保存1个月后,膜片诊断效果不变,对照反应均成立,该方法重复性好（重复符合率为93.9%）,操作简便（3 h内可完成）,不需要特殊检测仪器,结果客观,肉眼易于判断,是微生物和传染病及寄生虫病诊断标准化的新技术之一。     

鸡传染性支气管炎病毒免疫机制和免疫预防研究进展

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。     

鸡新城疫、减蛋综合征、传染性支气管炎三联油佐剂灭活苗的研究Ⅰ、三联灭活苗对鸡免疫试验

用新城疫病毒克隆７９株，减蛋综合征病毒ＮＥ＿４株和传染性支气管炎病毒Ｍ＿（４１）株分别接种于鸡胚和鸭胚，并收取其鸡、鸭胚尿囊液毒，经甲醛灭活，按一定比例配比，以矿物油为佐剂制成三联油佐剂灭活苗。本苗接种于产蛋后备鸡，免疫后７天产生免疫应答，免疫后３０天保护率达９０％～１００％，免疫后六个月攻毒，ＮＤ和ＩＢ保护宰为１００％，ＥＤＳ＿（７６）为９５％。１９９２～１９９４上半年，本苗在江苏、安徽、山东等省的一些鸡场免疫十万余只鸡，均获得满意效果。     

禽副黏病毒4型荧光RT-PCR检测方法的建立

本研究根据GenBank发表的禽副黏病毒4型（APMV-4）基因组序列,在保守区域分别设计了特异性RT-PCR引物和荧光探针,初步建立了可用于检测APMV-4的荧光RT-PCR方法。特异性试验表明本方法特异性强,与新城疫病毒（NDV）、禽流感病毒（AIV）、传染性支气管炎病毒（IBV）、减蛋综合征病毒（EDSV）等没有交叉反应。灵敏度试验表明本方法的检测下限为1EID50,比常规RT-PCR的敏感度高100倍左右。本研究所建立的荧光RT-PCR方法具有快速、准确、灵敏等优点,可用于APMV-4样品的检测。     

An egg drop associated with splenomegaly in broiler breeders

A new disease in broiler breeders known in Australia as Big Liver and Spleen Disease (BLS) is described from field observations, retrospective record analysis, and detailed study of a selected flock. BLS has a predilection for adult birds. It is characterized clinically by a sudden drop in egg production, splenomegaly, hepatomegaly, and increased mortality and histologically by a period of lymphoproliferation followed by a period of lymphoid destruction that coincides with the clinical signs. Epidemiology suggests an infectious cause, though initial attempts at isolation of a causative agent have been unsuccessful, and it is serologically distinct from the common avian viral and mycoplasma diseases.     

鸡新城疫、减蛋综合症、传染性支气管炎三联油佐剂灭活苗的研究Ⅱ、不同单位病毒配比的三联苗对鸡免疫抗体产生的影响

分别用三个滴度的ＮＤＶ、ＥＤＳ_７６Ｖ、ＩＢＶ作正交配比，制成八组不同配比的三联油佐剂灭活苗，鸡免疫后每月采血分离血清，应用ＨＩ监测其抗体，结果表明，三种病毒适当配比，不产生干扰，疫苗的免疫效果与抗原量有关。本疫苗与Ｉｎｔeｒｖｃｔ公司生产的ＮＤ－ＩＢ－ＩＢＤ三联油佐剂灭活苗作比较试验，免疫鸡所产生的ＮＤ、ＩＢ抗体无显著性差异。应用含抗原量最低口比的疫苗，对不明原因的有产蛋率下降疫病感染史的鸡群作免疫接种，冬季该场蛋鸡群普遍发生产蛋率明显下降的疫病，用本苗免疫的鸡群产蛋享未受影响。     

Protection of laying hens against infectious bronchitis with inactivated emulsion vaccines

Commercially-reared laying chickens were challenged at 31 weeks of age with a virulent infectious bronchitis (IB) virus. They showed a sharp drop in egg production, despite having been vaccinated at four and eight weeks old with live attenuated IB vaccines to a recommended schedule. In contrast, similar birds that had been further immunised at point-of-lay with inactivated oil emulsion IB vaccine, or with a combined IB/Newcastle disease (ND) emulsion vaccine, showed no detectable fall in egg production after the same challenge. Unvaccinated susceptible specific pathogen-free birds challenged at the same time stopped laying almost completely. In the birds revaccinated with emulsion vaccine, measurement of haemagglutination inhibition antibody levels to IB showed their geometric mean titres to be raised from less than 5 log2 at the time of vaccination to over 10 log2 four weeks later. Their antibody levels did not rise further followining the IB challenge whereas in the birds that had not been revaccinated antibody rises to nearly 10 log2 were detected after the same challenge. For pullets vaccinated earlier with live IB vaccine, revaccination with inactivated IB or IB/ND oil emulsion vaccine at point-of-lay provides a safe and effective way of protecting their egg production against IB infection.     

Prevalence of avian influenza,Newcastle disease,and infectious bronchitis viruses in broiler flocks infected with multifactorial respiratory diseases in Iran, 2015–2016

In this study, the prevalence and spatial distribution of Newcastle disease, infectious bronchitis, and avian influenza have been evaluated in commercial broiler farms in 31 provinces in Iran. In this survey, a total of 233 affected broiler chicken farms were sampled. The infectious bronchitis virus (alone) was detected with highest frequency in 60 farms, and separately or combined with other agents, in 110 farms; Newcastle disease virus, separately, was detected in 28 farms, and in 63 farms separately or combined with other infectious agents; and avian influenza H9N2 was detected in 22 farms separately and in 51 farms separately or concomitant with other infectious agents. The sample tested negative for all H5 serotypes. The results of the present study show that the most prevalent avian viral infectious disease contributing to respiratory syndromes in broiler farms in Iran was infectious bronchitis due to infectious bronchitis virus serotypes variant 2 and 793/B. On the other hand, combined with the alternation of dominant viruses and circulating strains, flocks are exposed to unremitting anamorphic viral infections. Thus, the permanent monitoring of cases that have occurred and the review of vaccination plans of affected flocks every year are some of the necessary measures needed for strategic control of respiratory syndrome in broilers. It is noteworthy that execution of epidemiologic examinations on the cogent factors of prevalence of this syndrome and defeat of vaccination strategy in the flocks is urgent and has to be fulfilled on the definite causes of time.

     

中兽药新制剂清瘟败毒颗粒对鸡人工感染支气管炎的防治试验

鸡传染性支气管炎是一种急性高度接触性呼吸道传染病,影响鸡的产蛋量和蛋品质。本研究以鸡传染性支气管炎病毒标准株M41人工感染21日龄700只海兰褐雏鸡,使其发病。接种病毒前后在饮水中分别添加不同剂量的清瘟败毒颗粒,以清瘟败毒散为对照治疗组,观察不同处理鸡的临床症状、发病率、病理变化和死亡率等。结果表明：饮水中添加0．z5％o清瘟败毒颗粒,对IBV标准株M41的攻毒保护作用与阳性对照组相比较差异显著（P〈0．05）;清瘟败毒颗粒低剂量治疗组与高、中剂量治疗组及清瘟败毒散治疗组之间差异显著,因水中添加0．5‰清瘟败毒颗粒,对人工感染鸡传染性支气管炎治疗作用明显,治愈率达88．00％,显著高于清瘟败毒散治疗组（P〈0．05）。     

Isolation of infectious bronchitis virus from intestine and reproductive organs of laying hens with dropped egg production

A total of 52 samples (22 cloacal swabs and 30 pooled ovaries and oviducts) from hens with a history of a 25 to 40% drop in egg production from 30 flocks were examined for the isolation of infectious bronchitis virus in embryonated chicken eggs. Five isolates were obtained: three from cloacal swabs and two from reproductive organs. These isolates were identified and characterized on the basis of agar-gel-precipitation, hemagglutination, and neutralization tests and other physicochemical characteristics.     

ISOLATION OF A HAEMAGGLUTINATING ADENO-LIKE VIRUS RELATED TO VIRUS 127 FROM AN AUSTRALIAN POULTRY FLOCK WITH AN EGG DROP SYNDROME

An egg drop syndrome within Australian broiler poultry is described. The syndrome was characterised by delayed onset of laying, a lower peak in egg production and a drop in egg production shortly after reaching peak production. Antibody to virus 127 was detected in 102 of 106 fowl serums tested. Two haemagglutinating viruses were isolated from one affected flock and one was subjected to further study. It was adenovirus-like on electron-microscopic examination and haemagglutination was not inhibited by a specific antiserum to Newcastle disease virus. An antiserum was raised in White Leghorn fowl against the isolate and this antiserum was found to cross-react with virus 127, a prototype virus of Egg Drop Syndrome 76.     

鸡传染性支气管炎LDT3-A株冻干苗对蛋种鸡的免疫效果观察

本试验旨在对中国自主研发的LDT3-A株鸡传染性支气管炎冻干苗(简称LDT3-A株传支冻干苗)在蛋种鸡中的应用效果进行观察比较。试验组和对照组初免分别使用LDT3-A株传支冻干苗和Ma5+clone30二联冻干苗免疫,在初免后均按照鸡场原定的免疫程序实施其他传支活毒疫苗(如H120、H52)和灭活疫苗免疫,初免后2组所用疫苗完全一致。试验结果显示,LDT3-A株传支冻干苗在父母代蛋种鸡3日龄时1.2倍量滴鼻免疫,免疫后应激反应较小;2组在随后实施相同的其他传支活毒疫苗和灭活疫苗加强免疫的基础上,试验组鸡群得到了有效保护,而对照组鸡群发生了传染性支气管炎疫情。试验期内试验组鸡群总死亡率较对照组降低10.11%;151~210日龄段的平均产蛋率提高了7.0%,种蛋合格率、受精率、出雏率和健雏率分别提高3.0%、2.3%、0.7%和3.2%,料蛋比降低了0.1。研究结果为蛋种鸡场优化筛选鸡传染性支气管炎免疫用疫苗和免疫程序,以及提高其免疫预防效果提供了临床依据。     

Characterization of infectious bronchitis viruses isolated from outbreaks of disease in commercial flocks in Brazil

Fifteen isolations of infectious bronchitis (IB) virus were made from a total of 126 Brazilian poultry flocks of all ages that were examined. These flocks (14 chicken and 1 quail) were experiencing a variety of IB-like conditions including respiratory disease, digestive and kidney problems, and drops in egg production. One of the isolates was of the Massachusetts serotype. The remainder were examined by means of cross-neutralization tests in tracheal organ cultures and were shown to belong to at least four antigenic groups, all different from ones described previously in other countries. Some, but not all, of the flocks from which they were isolated had been vaccinated against IB with vaccines of the Massachusetts serotype. In vivo protection studies showed that the MA5 vaccine (of the Massachusetts serotype) protected well against challenge with four of these isolates, representing the different serotypes reported in this study.     

Immune responses of breeding chickens to trivalent oil emulsion vaccines: responses to infectious bronchitis

Three similar flocks of broiler breeder parent chickens that had been given live infections bronchitis (IB) vaccines during rearing were injected at 20 weeks of age with three different oil emulsion vaccines: a commercial monovalent Newcastle disease (ND) vaccine (flock A); an experimental bivalent vaccine containing ND and infectious bursal disease (IBD) components (flock B); and an experimental trivalent vaccine containing ND, IBD and IB components (flock C). One week after vaccination 40 hens from flock A and 40 from flock C were taken to the laboratory and their egg yields individually recorded. At 37 weeks of age they were challenged by aerosol exposure to virulent IB virus. The egg production dropped significantly in the hens from flock A but not in the hens from flock C. On the farm, flock C showed a higher mean IB virus antibody titre four weeks after vaccination but titres rose in all three flocks indicating the presence of active IB virus infection. No differences in egg yields were found between the three farm flocks.     

Efficacy of experimental inactivated mycoplasma gallisepticum oil-emulsion bacterin in egg-layer chickens

Six groups of white leghorn pullets were studied to determine the ability of beta-propiolactone-inactivated Mycoplasma gallisepticum (MG) oil-emulsion bacterins to counteract reductions in egg production caused by MG infection. The pullets were inoculated with 0.5 ml of MG bacterin subcutaneously in the neck at about 20 weeks of age and were challenged with MG near 28 weeks of age, when they were in peak egg production. Various challenge schemes with infectious bronchitis virus were used at the time of MG challenge to increase the reduction in egg production. MG bacterins afforded protection against moderate drops in egg production in at least three of the studies, where the unvaccinated challenged control hens exhibited reduced egg production.