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1.
以伤寒─鼠伤寒双价重组株Vi4072的3×108CFU一次口服感染BALB/C小鼠,4天后即可从小鼠的集合淋巴结、肝、脾中分离到该菌,49天后该菌始被小鼠机体彻底清除。血清和小肠匀浆液中Vi抗体检测结果证明Vi4072菌株有刺激特异性免疫应答的功能。血清、小肠匀浆液中Vi抗体明显升高。  相似文献   

2.
将编码Vi抗原的基因克隆到减毒的鼠伤寒沙门氏菌中组建的基因重组株Vi4072,以3×10~8CFU一次口服感染Balb/C小鼠,4天后按7,14,21,28,35,42,49,56,63,70天的间隔收集分离小鼠的集合淋巴结,肝,脾.鉴别是否有本菌出现,并检测血清和小肠匀浆液中的vi抗体.结果表明,感染后49天仍可从脾中分离到该菌;70天仍可从血清和小肠匀浆液中测出vi抗体。  相似文献   

3.
伤寒─鼠伤寒重组株Vi4072所产生Vi抗原以伤寒Ty2株所产Vi抗原作对照,通过ED50测定和小白鼠被动保护试验作了比较,结果表明Vi4072株Vi抗原的半数有效剂量为0.0136μg,Ty2株的半数有效剂量为0.0183μg,说明Vi4072─Vi对小白鼠的保护作用不低于Ty2─Vi。被动保护试验证明,在同等条件下,两种Vi抗原的免疫血清对小白鼠提供的保护作用相同。  相似文献   

4.
伤寒─鼠伤寒重组株Vi4072所产生Vi抗原以伤寒Ty2株所产Vi抗原作对照,通过ED50测定和小白鼠被动保护试验作了比较,结果表明Vi4072株Vi抗原的半数有效剂量为0.0136μg,Ty2株的半数有效剂量为0.0183μg,说明Vi4072─Vi对小白鼠的保护作用不低于Ty2─Vi。被动保护试验证明,在同等条件下,两种Vi抗原的免疫血清对小白鼠提供的保护作用相同。  相似文献   

5.
滕家波  张毅 《微生物学报》1999,39(6):533-538
将编码肠毒素源性大肠杆菌定居因子抗原CS6基因克隆到pXL670,转化asd基因突变的E.coli X6097,获得重组质粒pSS64,再将后者转化至减毒的△aroA、△aroC、△asd伤寒沙门氏菌,构建了无药物抗性且稳定的大肠杆菌和伤寒双价菌苗候选株。小鼠腹腔免疫和攻击实验表明,该菌株对伤寒沙门氏菌毒株的攻击具有良好的保护作用。家兔免疫实验证明,该菌株能产生抗CS6和伤寒菌Vi抗原的血清抗体。  相似文献   

6.
被动血凝试验测定伤寒Vi抗体   总被引:4,自引:0,他引:4  
作者从拘橼酸杆菌中提取纯化获得其Vi多糖抗原,该抗原具有伤寒沙门氏菌Vi抗原的免疫学特性,而不含伤寒沙门氏菌0,H抗原,用其致敏新鲜羊血球作被动血凝试验,特异性敏感性均很好。所需Vi抗原致敏浓度极低,仅为0.05ug/ml。使用新鲜羊血球凝模式较好,便于观察结果,采用被动血凝试验检测106名健康中学生肌肉注射30ug伤寒Vi多糖菌苗前后Vi抗体的变化情况,发现免疫后血清抗体的四倍增长率达89%,表明伤寒Vi多糖苗具有良好的免疫原性。  相似文献   

7.
将含有编码Vi抗原ViaB基因片断的质粒转导进入宋内氏痢疾菌无毒株S7中,组建了重组菌株S7Vi。质粒电泳图谱显示重组菌株S7Vi中存在被转入的外源质粒带。重组株的生化特性没有改变。菌体凝集及Vi抗血清标记的SPA菌液凝集反应证明在重组株的菌体表面,同时表达了Vi抗原和宋内氏毒菌的O抗原。以5×10~8CFU、10×10~8CFU的重组株免疫近交系的LIBP小鼠,免疫小鼠对宋内氏毒株S63攻击的保护率为60%至90%,对伤寒毒株Ty2攻击的保护率为25%至40%。  相似文献   

8.
表达霍乱CT-B和LPS-O抗原的鼠伤寒菌苗株的构建   总被引:5,自引:0,他引:5  
将编码霍乱CT-B和LPS-O抗原的基因与载体质粒pYA248重组后,转入△cya△crp△asd减毒鼠伤寒疫苗株x4072构建成无药物抗性,带双价抗原的工程菌株x4072(pMG306)。该菌株能分泌表达特异的霍乱CT-B抗原,并且在菌体表面同时表达霍乱和鼠伤寒的O抗原。小鼠腹腔免疫和攻击试验表明该菌株对霍乱毒株的攻击具有良好的保护作用。本研究为新型献计霍乱/鼠伤寒双价口服活疫苗的构建打下了基础  相似文献   

9.
火箭电泳法测定伤寒Vi多糖菌苗多糖含量   总被引:4,自引:2,他引:2  
伤寒沙门氏菌Vi抗原系a─1,4─N─乙酰─半乳糖醛酸高度聚合体,其C2和C3位分别被N─乙酰基和0─乙酰基取代,它不能用分光光度法测定其含量,实验表明火箭电泳的火箭峰高与其样品中多糖含量的对数成直线相关关系,作者采用火箭电泳方法对全国六个生物制品研究所的18批伤寒Vi多糖菌苗中Vi多糖含量进行了测定,结果表明多数制品符合规程要求,但部分制品多糖含量偏高,值得引起注意,各所三批制品差别不大,表明各所的生产工艺相对稳定,利用火箭电泳测定伤寒Vi多糖,操作简单,用时较短,所需样品极少,是目前较为合适的测定伤寒Vi多糖菌苗多糖含量的方法。  相似文献   

10.
通过对鼠伤寒沙门菌LH株的发酵培养,热酚水法提取脂多糖LPS,1%乙酸沸水浴水解90m in脱毒,Super-dex 200柱层析,收集第一峰为鼠伤寒O-SP抗原;然后用CDAP对O-SP活化、ADH衍生后,在EDAC的缩合作用下,结合到破伤风类毒素TT上,制备出鼠伤寒结合疫苗;用含2.5μg多糖鼠伤寒结合疫苗免疫小鼠,以2.5μgO-SP多糖生理盐水溶液以及生理盐水溶液为对照组,间隔14天,免疫三针;以LPS为包被抗原,用间接ELISA法测定血清中抗鼠伤寒LPS IgG抗体。鼠伤寒结合疫苗三针免疫后,小鼠血清抗鼠伤寒LPS IgG抗体效价达到1:80以上的比例为84.2%,而总的几何平均滴度(GMT)达到796;说明制备的鼠伤寒结合疫苗有良好的免疫原性,而且鼠伤寒结合疫苗在小鼠和豚鼠体内有良好的安全性。  相似文献   

11.
Vi-agglutinin, active cutaneous anaphylaxis and protective responses (ed(50)) of three mouse strains (CFW, NIH, and Balb/cAnN) to acetone-inactivated typhoid vaccine and soluble Vi antigen were compared. Seven days after immunization with either typhoid vaccine or Vi antigen the three strains of mice differed with respect to Vi-antibody titers. Significant differences were observed in the protective responses. Each mouse strain was significantly better protected by the intraperitoneal than by subcutaneous route of immunization. Active cutaneous anaphylaxis was more pronounced in showing strain differences in response to Vi antigen. The serological responses to Vi antigen of the strains of mice did not correlate with their protective response.  相似文献   

12.
MM-3 was a live vaccine strain candidate for protecting neonatal piglets from diarrhea.Designed in the 1980s,a high degree of protection from colibacillosis was afforded to piglets in a challengestudy and field trials.However MM-3 had a drawback of carrying the antibiotic resistance gene (chloramphenicolacetyltransferase gene,cat).The introduction of a host-plasmid balanced lethal system into the vaccine wasa good idea to solve the problem.The λ-Red recombination system was adopted in this study to realize thereplacement of cat by aspartate-semialdehyde dehydrogenase gene (asd) in the plasmid pMM085.The newplasmid named pMMASD was introduced into an Escherichia coli strain χ6097 and Salmonella typhimuriumχ4072 where the asd gene had been knocked out in their chromosomes.Cultured in an Erlenmeyer flask,expression levels of two antigens K88ac fimbriae and heat-labile enterotoxin B subunit (LTB) in cell lysatewere similar among MM-3,χ4072(pMMASD) and χ6097(pMMASD).However,χ4072(pMMASD) possessedthe more effective secretion mechanism to transport LTB enterotoxin into culture liquid.The relatively higherstability of pMMASD in Salmonella typhimurium χ4072 than that of pMM085 in MM-3 was determined bothin vitro in the absence of selective pressure,and in vivo following oral inoculation.Oral immunization ofBALB/c mice with χ4072(pMMASD) or χ6097(pMMASD) was sufficient to elicit IgA responses in mucosaltissues as well as systemic IgG antibody responses to the K88 fimbriae,while MM-3 failed to elicit specificantibody responses to K88 fimbriae in mucosal tissues.Among three live strains,only χ4072(pMMASD)could develop strong humoral responses against LTB enterotoxin.The results suggest that χ4072(pMMASD)is expected to be a promising live vaccine strain.  相似文献   

13.
为构建表达幽门螺杆菌(Hp)黏附素保守区(AB)的无抗性减毒鼠伤寒沙门氏菌疫苗,采用缺失腺苷酸环化酶基因(Δcya)、环腺苷酸受体蛋白基因(Δcrp)以及天冬氨酸β-半醛脱氢酶基因(Δasd)的鼠伤寒沙门菌(X4072)作为宿主,将编码AB的基因插入Asd+的组成型表达载体pYA248,通过两次转化引入宿主菌,构建了表达AB基因平衡致死的减毒鼠伤寒沙门重组菌X4072(pYA248-AB),采用桥联法ELISA测定X4072(pYA248-AB)培养上清液和裂解上清液中AB的抗原性,参照Meacock叙述的方法及重组菌生长曲线的测定来确定重组菌株的稳定性,通过C57BL/6小鼠口服测定半致死量来确定重组菌的安全性。成功构建了表达AB的减毒鼠伤寒沙门菌重组菌株S.typhimurium X4072(pYA248-AB),桥联法ELISA测定表明重组菌X4072(pYA248-AB)培养上清中AB的含量高于菌体裂解液,重组菌pYA248-AB在没有选择压力的情况下培养100代,随机挑选的重组菌全部都能生长,且在ELISA测定AB抗原时均显阳性。重组菌的生长曲线测定表明,X4072(pYA248)和X4072(pYA248-AB)的生长状态基本一致;口服重组菌株X4072(pYA248-AB)1.0×1010cfu.30d后,C57BL/6存活率仍为100%。成功构建了表达AB的无抗性的减毒鼠伤寒沙门菌疫苗X4072(pYA248-AB),体外实验表明重组质粒是稳定的,动物实验证明重组菌株是安全的;为防治幽门螺杆菌感染提供了口服活菌疫苗候选株。  相似文献   

14.
编码LT-B/ST融合抗原的基因插入pYA248载体中,构建了重组质粒pXZL66。该重组质粒转入无毒鼠伤寒沙门氏菌SR-11,ΔCya,Δcrp,Δasd菌株X4072。此无抗药性的杂合菌株X4072(pXZL66)表达的LT-B/ST融合抗原具有LT和ST抗原性而没有生物毒性,可望成为预防ETEC腹泻和相应的沙门氏菌病双价口服活疫苗候选株。  相似文献   

15.
The Vi capsular polysaccharide is a virulence-associated factor expressed by Salmonella enterica serotype Typhi but absent from virtually all other Salmonella serotypes. In order to study this determinant in vivo, we characterised a Vi-positive S. Typhimurium (C5.507 Vi(+)), harbouring the Salmonella pathogenicity island (SPI)-7, which encodes the Vi locus. S. Typhimurium C5.507 Vi(+) colonised and persisted in mice at similar levels compared to the parent strain, S. Typhimurium C5. However, the innate immune response to infection with C5.507 Vi(+) and SGB1, an isogenic derivative not expressing Vi, differed markedly. Infection with C5.507 Vi(+) resulted in a significant reduction in cellular trafficking of innate immune cells, including PMN and NK cells, compared to SGB1 Vi(-) infected animals. C5.507 Vi(+) infection stimulated reduced numbers of TNF-α, MIP-2 and perforin producing cells compared to SGB1 Vi(-). The modulating effect associated with Vi was not observed in MyD88(-/-) and was reduced in TLR4(-/-) mice. The presence of the Vi capsule also correlated with induction of the anti-inflammatory cytokine IL-10 in vivo, a factor that impacted on chemotaxis and the activation of immune cells in vitro.  相似文献   

16.
Gaines, Sidney (Walter Reed Army Institute of Research, Washington, D.C.), Julius A. Currie, and Joseph G. Tully. Factors affecting formation of incomplete Vi antibody in mice. J. Bacteriol. 90:635-642. 1965.-Single immunizing doses of purified Vi antigen elicited complete and incomplete Vi antibodies in BALB/c mice, but only incomplete antibody in Cinnamon mice. Three of six other mouse strains tested responded like BALB/c mice; the remaining three, like Cinnamon mice. Varying the quantity of antigen injected or the route of administration failed to stimulate the production of detectable complete Vi antibody in Cinnamon mice. Such antibody was evoked in these animals by multiple injections of Vi antigen or by inoculating them with Vi-containing bacilli or Vi-coated erythrocytes. The early protection afforded by serum from Vi-immunized BALB/c mice coincided with the appearance of incomplete Vi antibody, 1 day prior to the advent of complete antibody. Persistence of incomplete as well as complete antibody in the serum of immunized mice was demonstrated for at least 56 days after injection of 10 mug of Vi antigen. Incomplete Vi antibody was shown to have blocking ability, in vitro bactericidal activity, and the capability of protecting mice against intracerebral as well as intraperitoneal challenge with virulent typhoid bacilli. Production of incomplete and complete Vi antibodies was adversely affected by immunization with partially depolymerized Vi antigens.  相似文献   

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