口服人参皂苷Rg1提高鸡的肠道黏膜免疫

将96只SPF母鸡随机分成4组,1,4组注射生理盐水;2,3组连续3 d肌肉注射环磷酰胺(Cy)诱导免疫抑制。3组在Cy引起免疫抑制后连续7 d每天饮水口服1 mg/kg人参皂甙Rg1,其余组只饮水。1,2,3组于给药结束后免疫传染性法氏囊病毒(IBDV)疫苗,4组不免疫。于给药前和免疫后1,2,3周计算脾脏和法氏囊指数,采血测定抗体阳性率,检测十二指肠灌洗液总sIgA和特异性sIgA含量;观察十二指肠黏膜上皮内淋巴细胞(IELs)以及IgA+细胞数。于免疫后1周提取十二指肠总RNA,检测肠组织免疫相关基因mRNA的表达。结果表明,和免疫抑制组相比,饮水口服1 mg/kg人参皂苷Rg1可提高IBDV抗体阳性率,显著增加脾脏和法氏囊指数,显著提高肠道总sIgA和特异性sIgA含量;此外,口服Rg1显著增加了十二指肠IELs和固有层IgA+细胞数量,上调了鸡十二指肠TLR4、p65、TGF-β、pIgR和CCR9基因的mRNA表达水平。     

Avian influenza mucosal vaccination in chickens with replication-defective recombinant adenovirus vaccine

We evaluated protection conferred by mucosal vaccination with replication-competent adenovirus-free recombinant adenovirus expressing a codon-optimized avian influenza (AI) H5 gene from A/turkey/WI/68 (AdTW68.H5ck). Commercial, layer-type chicken groups were either singly vaccinated ocularly at 5 days of age, singly vaccinated via spray at 5 days of age, or ocularly primed at 5 days and ocularly boosted at 15 days of age. Only chickens primed and boosted via the ocular route developed AI systemic antibodies with maximum hemagglutination inhibition mean titers of 3.9 log2 at 32 days of age. In contrast, single vaccination via the ocular or spray routes maintained an antibody status similar to unvaccinated controls. All chickens (16/16) subjected to ocular priming and boosting with AdTW68.H5ck survived challenge with highly pathogenic AI virus A/chicken/Queretaro/14588-19/95 (H5N2). Single ocular vaccination resulted in 63% (10/16) of birds surviving the challenge followed by a 44% (7/16) survival of single-sprayed vaccinated birds. Birds vaccinated twice via the ocular route also showed significantly lower (P < 0.05) AI virus RNA concentrations in oropharyngeal swabs compared to unvaccinated-challenged controls.     

Duration of immunity induced in chickens by an attenuated live Salmonella enteritidis vaccine and an inactivated Salmonella enteritidis/typhimurium vaccine

The aim of this study was to examine the duration of immunity of different vaccination schemes using the S. enteritidis live vaccine Gallivac Se and the S. enteritidis-S. typhimurium inactivated vaccine Gallimune Se+St. Three groups of Lohman Brown chickens were used. Group one was vaccinated three times orally with Gallivac Se at weeks one, seven and 13 of age. Group two was vaccinated twice orally with Gallivac Se in weeks one and seven and once i.m. with Gallimune Se+St in week 14 of age. A third group was not vaccinated and served as the control group. Eight randomly selected chickens from each of the three groups were challenged with a nalidixic acid resistant S. enteritidis PT4 strain in weeks 24, 51 and 71 of age and the same number of animals were challenged with a S. typhimurium DT 104 strain in weeks 26, 54 and 73 (75) of age.The chickens were euthanised seven days post challenge and the number of challenge strain organisms (log10 cfu) in the liver and on caecal mucosa was determined.The quantitative investigation of the challenge strain in the liver and caecal mucosa revealed a statistically significant (p < 0.05) lower challenge strain burden in the vaccinated groups compared with the non-vaccinated control group up to week 71 (73) of age. The protective effects were demonstrated for both challenge strains.     

Improved immune responses against avian influenza virus following oral vaccination of chickens with HA DNA vaccine using attenuated Salmonella typhimurium as carrier

This study evaluates the immune responses of single avian influenza virus (AIV) HA DNA vaccine immunization using attenuated Salmonella enterica sv. Typhimurium as an oral vaccine carrier and intramuscular (IM) DNA injection. One-day-old specific-pathogen-free (SPF) chicks immunized once by oral gavage with 10(9) Salmonella colony-forming units containing plasmid expression vector encoding the HA gene of A/Ck/Malaysia/5858/04 (H5N1) (pcDNA3.1.H5) did not show any clinical manifestations. Serum hemagglutination inhibition (HI) titer samples collected from the IM immunized chickens were low compared to those immunized with S. typhimurium.pcDNA3.1.H5. The highest average antibody titers were detected on day 35 post immunization for both IM and S. typhimurium.pcDNA3.1.H5 immunized groups, at 4.0±2.8 and 51.2±7.5, respectively. S. typhimurium.pcDNA3.1.H5 also elicited both CD4(+) and CD8(+) T cells from peripheral blood mononuclear cells (PBMCs) of immunized chickens as early as day 14 after immunization, at 20.5±2.0 and 22.9±1.9%, respectively. Meanwhile, the CD4(+) and CD8(+) T cells in chickens vaccinated intramuscularly were low at 5.9±0.9 and 8.5±1.3%, respectively. Immunization of chickens with S. typhimurium.pcDNA3.1.H5 enhanced IL-1β, IL-12β, IL-15 and IL-18 expressions in spleen although no significant differences were recorded in chickens vaccinated via IM and orally with S. typhimurium and S. typhimurium.pcDNA3.1. Hence, single oral administrations of the attenuated S. typhimurium containing pcDNA3.1.H5 showed antibody, T cell and Th1-like cytokine responses against AIV in chickens. Whether the T cell response induced by vaccination is virus-specific and whether vaccination protects against AIV infection requires further study.     

Detection and screening of Salmonella enteritidis-infected chickens with recombinant flagellin.

Screening and identification of Salmonella enteritidis in commercial poultry flocks have assumed principal roles in preventing transmission of this pathogen to humans from hen eggs. Serologic diagnosis of S. enteritidis infection in commercial flocks currently relies on laboratory-based tests for detection of antibodies to the lipopolysaccharide, whole flagella, and bacteria. We amplified a sequence from the g,m flagellin of S. enteritidis, followed by cloning, expression, and purification of the protein. The recombinant protein was first characterized by western blot and subsequently evaluated as enzyme-linked immunosorbent assay (ELISA) antigen for detection of S. enteritidis infection. A total number of 49 positive sera and 40 negative sera were tested for ELISA validation. A cutoff value of 0.14 was shown to be sufficient to discriminate the negative and positive sera. Results obtained by testing sera raised against different bacterial strains/serotypes further confirmed that this recombinant flagellin-based ELISA was indeed specific for the detection of S. enteritidis. Both sensitivity and specificity of the developed ELISA test were comparable with a commercially available test, indicating that it is a highly promising and reliable diagnostic tool for S. enteritidis infection.     

鸡新城疫-鸡传染性支气管炎-禽流感-产蛋下降综合征四联灭活油乳剂疫苗的研制与免疫试验

用鸡新城疫La Sota株,鸡传染性支气管炎H120株,产蛋下降综合征127株和禽流感病毒HB1(H9N2)株做为抗原制成油乳剂灭活联苗,并对其进行了物理性状、纯净、安全性、灭活效果、保存期和免疫效力等方面的检验.证明所制备疫苗完全符合质量标准;鸡体对该疫苗4种抗原均产生了良好的免疫应答;攻毒试验证明,免疫鸡能良好地抵抗同种强毒的攻击;所制备疫苗于2～8℃保存12个月后,其免疫效力没有下降.     

禽流感的流行特点和综合防制

禽流感（AI）是由A型流感病毒引起的一种传染性疾病。本病传播迅速且形式多样，病毒亚型多，易变异，致死率高，一旦发生，很难控制。几乎所有家禽在任何年龄段均对流感病毒易感。本病迄今在世界上已流行１００多年，每次爆发该病，均对养禽业造成毁灭性打击。近年来，禽流感在世界各国的爆发呈上升趋势，特别是１９９７年香港爆发的禽流感已经对人类的健康构成了威胁。至此，引起了世界各地的广泛关注。国际兽医局动物流行病组织（OIE）和我国《家畜家禽防疫条例》都将此病列为一类传染病。１禽流感的病毒特性和流行病学特征１．１病毒…     

4种中药多糖对免疫雏鸡黏膜免疫功能的影响

为了探讨4种多糖增强雏鸡黏膜免疫的作用和机理.将450羽罗曼公鸡随机分成9组,14日龄用新支二联弱毒苗点眼滴鼻,同时,8个试验组分别肌肉注射高、低剂量的黄芪多糖(APS)、板蓝根多糖(IRPS)、牛膝多糖(AIRPS)和山药多糖(CYPS)溶液,对照组注射生理盐水,连续注射3 d,1次/d.于免疫后第10 d、20 d、30 d、40 d、50 d和60 d每组随机抽取5羽迫杀,刮取空肠黏液,用ELISA方法测定SIgA的含量;采盲肠扁桃体和十二指肠.用免疫组织化学法测定盲肠扁桃体和肠绒毛SIgA细胞阳性面积.实验结果表明:4种多糖均能显著提高空肠黏液中SIgA的含量和盲肠扁桃体、小肠绒毛的SIgA阳性细胞数,低剂量的APS、IRPS的效果优于高剂量的ARPS、CYPS.提示4种多糖均可以有效地增强黏膜的屏障作用,从而提高机体抗感染能力.     

蛋鸡低致病性禽流感(H9亚型)的防制体会

一 临床诊断新特点 1 冬春季节易流行,夏秋季节照样发病,切不可误认为天热时就不得禽流感了。     

禽流感免疫水平低下的原因剖析

近几年，世界许多国家相继发生了禽流感疫病，禽流感疫情形势十分严峻。多年来，禽流感油乳剂灭活苗在东阳市得到了广泛应用，东阳市畜牧兽医局化验室对大批次、大批量的家禽进行了禽流感抗体监测情况来看，还有许多养殖专业户的家禽的禽流感免疫效果不理想。为此就禽流感免疫水平低下的原因及对策进行了重点分析落实。     

Failure of a recombinant fowl poxvirus vaccine containing an avian influenza hemagglutinin gene to provide consistent protection against influenza in chickens preimmunized with a fowl pox vaccine

Vaccines against mildly pathogenic avian influenza (AI) have been used in turkeys within the United States as part of a comprehensive control strategy. Recently, AI vaccines have been used in control programs against highly pathogenic (HP) AI of chickens in Pakistan and Mexico. A recombinant fowl pox-AI hemagglutinin subtype (H) 5 gene insert vaccine has been shown to protect specific-pathogen-free chickens from HP H5 AI virus (AIV) challenge and has been licensed by the USDA for emergency use. The ability of the recombinant fowl pox vaccine to protect chickens preimmunized against fowl pox is unknown. In the current study, broiler breeders (BB) and white leghorn (WL) pullets vaccinated with a control fowl poxvirus vaccine (FP-C) and/or a recombinant fowl poxvirus vaccine containing an H5 hemagglutinin gene insert (FP-HA) were challenged with a HP H5N2 AIV isolated from chickens in Mexico. When used alone, the FP-HA vaccine protected BB and WL chickens from lethal challenge, but when given as a secondary vaccine after a primary FP-C immunization, protection against a HP AIV challenge was inconsistent. Both vaccines protected against virulent fowl pox challenge. This lack of consistent protection against HPAI may limit use to chickens without previous fowl pox vaccinations. In addition, prior exposure to field fowl poxvirus could be expected to limit protection induced by this vaccine.     

Comparative serological evaluation of avian influenza vaccine in turkeys

Four- and six-week-old turkeys were vaccinated subcutaneously using avian influenza virus (AIV) A/Duck/613/MN/79 (H4N2) killed oil-emulsion vaccine. Sequential serological tests using agar gel precipitin (AGP), hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) for measuring antibodies to AIV were performed up to 4 weeks postvaccination, when birds were challenged intranasally using A/Turkey/MN/80 (H4N2) live AIV. The ELISA was 25 to 1600 times more sensitive than the HI test and was able to detect antibody production earlier than the HI test. All turkeys with an ELISA titer of greater than or equal to 800 were protected against homologous challenge, as measured by virus recovery 3 days postchallenge. Four turkeys out of 20 serologically negative by AGP and HI tests but ELISA-positive were protected.     

Astragalus polysaccharide enhances immunity and inhibits H9N2 avian influenza virus in vitro and in vivo

This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.     

Astragalus polysaccharide enhances immunity and inhibits H9N2 avian influenza virus in vitro and in vivo

This study investigated the humoral immunization of Astragalus polysaccharide (APS) against H9N2 avian influenza virus (H9N2 AIV) infection in chickens.The effects of APS treatment on H9N2 infection was evaluated by an MTT [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.     

正确选择和使用禽流感疫苗

近年来,禽流感的爆发和流行引起了世界的广泛关注,如何控制和消灭该病的问题日益突出,实践证明接种禽流感疫苗是较为有效的预防方法。但是并不是说接种了禽流感疫苗就万事大吉、平安无事了,只有根据具体情况合理选用疫苗,把握好免疫的各个环节,才能达到良好的免疫效果。     

牛蒡苷元对禽流感疫苗的免疫增强作用

用牛蒡苷元(arctigenin,ACT)作佐剂,研究了牛蒡苷元对鸡禽流感疫苗的免疫增强效果。结果表明:牛蒡苷元对禽流感油乳剂灭活苗有较强的免疫增强作用,能够诱导雏鸡产生更高的抗禽流感抗体效价,腹腔巨噬细胞吞噬率和吞噬指数明显升高,对鸡胸腺、脾、法氏囊的发育均有一定的促进作用;T淋巴细胞E-花环率提高10%以上。     

Efficacy of avian influenza oil-emulsion vaccines in chickens of various ages

An experimental avian influenza (AI) oil-emulsion vaccine was formulated with 1 part inactivated A/turkey/Wisconsin/68 (H5N9) AI virus emulsified in 4 parts oil. Broilers were vaccinated subcutaneously (SC) either at 1 or 3 days old or at 4 or 5 wks old. Commercial white leghorn (WL) layers were vaccinated SC at 12 and 20 wks old or at only 20 wks old. Maximum geometric mean hemagglutination-inhibition titers postvaccination (PV) were 1:86-1:320 for broilers, 1:597 for twice-vaccinated layers, and 1:422 for once-vaccinated layers. Ninety to 100% of vaccinated broilers were protected against death and morbidity when challenged with highly pathogenic A/chicken/Penn/83 (H5N2) AI virus 4 weeks PV, and all were protected when challenged 8 wks PV. All controls and most vaccinates were infected by challenge virus, and 90-100% of controls died or exhibited clinical signs. Vaccinated commercial pullets were protected against morbidity, death, and egg-production decline at either peak of lay (25 wks old) or at 55 wks old. All unvaccinated controls became morbid or died, and egg production ceased 72 hours after challenge. The 0.5-ml vaccine dose was determined to contain 251 and 528 mean protective doses (PD50S) in 4-wk-old and 1-year-old SPF WL chickens, respectively, challenged 4 wks PV.     

Needle-free delivery of an inactivated avian influenza H5N3 virus vaccine elicits potent antibody responses in chickens

A needle-free delivery system was assessed as a route for providing quick, safe, and effective vaccination against avian influenza (AI). Two groups of chickens were vaccinated with a commercially available inactivated H5N3 virus vaccine delivered either with a needle-free device or with the conventional syringe-and-needle method recommended by the vaccine manufacturer. The kinetic aspects of seroconversion, peak antibody levels, and antibody titers were measured by a combination of an indirect enzyme-linked immunosorbent assay and the hemagglutination-inhibition test and were all found to be similar in the 2 groups of chickens. We conclude that the needle-free delivery system could result in effective immunization against H5N1 AI epidemics and pandemics in chickens.     

重组禽流感病毒H5亚型二价灭活疫苗(H5N1,Re-5+Re-4)免疫鸡和鸭后抗体消长规律

禽流感(AI)是由A型流感病毒引起的一种禽类传染病.根据致病性的不同将禽流感分为高致病性禽流感(HPAI)和低致病性禽流感(IPAI),HPAI被世界动物卫生组织(OIE)列为A类传染病,我国将其列为一类动物疫病 [1].近几年来,禽流感在世界各地反复出现,2004年亚洲发生了高致病性禽流感,2006年底和2007年初东南亚又出现疫情,并发现了人感染禽流感.我国养禽业也一直受到禽流感的威胁.因此,它不仅给畜牧业造成了巨大的损失,而且给人们的公共卫生安全带来了严重的威胁.