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1.
提取鸡致病性大肠杆菌分离株O1、O2和O78的基因组DNA作模板,用TD-PCR技术从其中分别扩增出0.55 KB的I型菌毛结构基因(piliA).将扩增得到的piliA基因片段,用TA克隆的方法分别克隆进pGEM-T栽体中,转化至受体菌JM109中,用Amp/IPTG/X-gal琼脂平板蓝白菌落筛选法,得到舍阳性重组子的菌株,提取质粒用PstI单酶切及NcoI和PstI双酶切鉴定,结果证实,所构建的克隆质粒中均含有相应piliA基因.经DNA序列分析,其结构基因阅读框架大小为549 bp,但其中O1菌株Ⅰ型菌毛基因在第72位发生突变,有6个碱基插入.经DNAStar核酸分析软件分析,3个基因同源性为89.9%~92.0%.  相似文献   

2.
提取鸡致病性大肠杆菌分离株O1,O2和O78的基因组DNA作为模板,用TD-PCR技术从其中分别扩增出了0.55kb的I型菌毛细菌基因(piliA),将扩增得到的piliA基因片段,TA克隆的方法分别克隆进pGEM-T载体中,转化至受体菌JM109中,用Amp/IPTG/X-gal琼脂平板蓝白菌落筛选法,得到含阳性重组子的菌株,提取质粒用PstI单酶切及NcoI和PstI双酶切鉴定,结果证实,所构建的克隆质粒中均含有相应piliA基因,经DNA序列分析,其结果基因阅读框架大小为549bp,但其中O1菌株I型菌毛基因在第72位发生突变,有6个碱基插入,经DNA Star核酸分析软件分析,此3菌株的I型菌毛基因的同源性为89.9%-92%。  相似文献   

3.
提取鸡致病性大肠杆菌分离株O1、O2和O78的基因组DNA作为模板,用TD-PCR技术从其中分别扩增出了0.55kb的I型菌毛结构基因(piliA)。将扩增得到的piliA基因片段,用TA克隆的方法分别克隆进pGEM-T载体中,转化至受体菌JM109中,用Amp/IPTG/X-gal琼脂平板蓝白菌落筛选法,得到含阳性重组子的菌株,提取质粒用PstI单酶切及NcoI和PstI双酶切鉴定,结果证实,所构建的克隆质粒中均含有相应piliA基因。经DNA序列分析,其结构基因阅读框架大小为549bp,但其中O1菌株I型菌毛基因在第72位发生突变,有6个碱基插入。经DNAStar核酸分析软件分析,此3菌株的I型菌毛基因的同源性为89.9%~92%。  相似文献   

4.
用限制性内切酶SacI和BamHI双酶切克隆有鸡致病性大肠杆菌分离株O1、O2和O78的piliA基因的质粒pTFimO1、pTFimO2和pTFimO78,分别回收从此3质粒上切下的545bp的piliA基因片段,再将载体pET-28a(+)用SacI和BamHI双酶切,最后将pET-28a(+)DNA片段与545bp的piliA DNA片段进行连接,转化至受体菌BL21(DE3)中,经SacI和BamHI酶切反应鉴定重组子,得到了理想重组子质粒pETFimO1、pETFimO2和pETFimO78.重组菌株BL21(DE3) (pETFimO1)、BL21(DE3)(pETFimO2)和BL21(DE3)(pETFimO78)经IPTG诱导后,其表达产物经SDS-PAGE检测,结果表明重组菌株可以良好地表达鸡致病性大肠杆菌Ⅰ型菌毛蛋白.  相似文献   

5.
用鸡致病性大肠杆菌分离株O1、O2和O78的基因组DNA做为模板,PCR分别扩增出了0.55kb的P型菌毛结构基因(papA)。将扩增得到的3个papA基因片段分别克隆进pGEM—T栽体中,转化至受体菌JM109中,用Amp/IPTG/X-gal琼脂平板蓝白菌落筛选法,得到含阳性重组子的菌株,提取质粒后用BamH Ⅰ和Sal Ⅰ双酶切进行鉴定。所得阳性重组子进行DNA序列测定,测序结果经DNA Star核酸分析软件包分析比较,结果表明,所构建的克隆质粒中均含有相应完整papA基因,其开放式阅读框架大小为549bp,编码182个氨基酸。此3株菌的P型菌毛结构基因的同源性为98.9%~100%,其中O1株和O78株的P型菌毛基因的ORF序列100%相同,O2株有2个碱基与前两者不同。  相似文献   

6.
用限制性内切酶SacI和BamHI双酶切克隆有鸡致病性大肠杆菌分离株O1、O2和O78的piliA基因的质粒pTFimO1、pTFimO2和pTFimO78,分别回收从此3质粒上切下的545bp的piliA基因片段,再将载体pET-28a( )用SacI和BamHI双酶切,最后将pET-28a( )DNA片段与545bp的piliA DNA片段进行连接,转化至受体菌BL21(DE3)中,经SacI和BamHI酶切反应鉴定重组子,得到了理想重组子质粒pETFimO1、pETFimO2和pETFimO78。重组菌株BL21(DE3),(pETFimO1)、BL21(DE3)(pETFimO2)和BL21(DE3)(pETFimO78)经IPTG诱导后,其表达产物经SDS-PAGE检测,结果表明重组菌株可以良好地表达鸡致病性大肠杆菌I型菌毛蛋白。  相似文献   

7.
根据Genebank中已登录的大肠杆菌O157:H7菌株EDL933基因序列中茵毛分子伴侣ycbR基因序列设计1对引物,并分别在其5'端分别加入Neo I、Xho I酶切位点,以大肠杆菌O157:H7国内分离株97094的DNA为模板,用聚合酶链反应(PCR)扩增出710 bp的DNA片段.回收并纯化该DNA片段,用限制性核酸内切酶Nco I、Xho I同时消化DNA片段和双酶切栽体质粒pET28a(+).将它们回收纯化并连接,然后转化到宿主菌大肠杆菌DH5a,从该菌中提取重组质粒,用PCR、限制性内切酶位点分析及核苷酸序列测定法对克隆的重组质粒进行鉴定,表明ycbR基因定向克隆到了载体质粒pET28a(+).再将重组质粒转化到表达宿主菌大肠杆菌BL21(DE3),在含Kan抗生素LB培养基中经IPTG诱导12~16 h,做SDS-PAGE分析,表明ycbR基因在菌株中获得高效表达,表达蛋白相对分子质量大小约为30 000,与预期结果一致.为研究大肠杆菌ycbR基因产物的功能和致病作用奠定了基础.  相似文献   

8.
犬新孢子虫NcSRS2基因原核表达质粒的构建   总被引:1,自引:0,他引:1  
根据已发表的犬新孢子虫NcSRS2基因序列,设计1对含有EcoRⅠ和NotⅠ酶切位点的引物。以提取犬新孢子虫虫体基因组DNA为模板,应用PCR扩增获得NcSRS2 ORF基因片段,将此基因片段克隆到pMD18-T Simple载体上,用EcoRⅠ和NotⅠ双酶切该片段,回收得到含有两个酶切位点黏端的Nc-SRS2 ORF基因,将此基因片段克隆至相同酶切回收后的PGEM-4T-2原核表达载体中,获得重组质粒pGEX-NcSRS2,经PCR鉴定,限制性内切酶分析和克隆片段序列测定比较,证实了重组质粒的正确性。  相似文献   

9.
为获得区别结核感染状态的血清学鉴别诊断试剂的抗原,根据GenBank中登录的结核杆菌H37Rv的ACR基因序列设计1对引物,以热灭活的结核杆菌H37Rv菌悬液为模板,PCR扩增得到ACR基因DNA片段.将扩增片段克隆于pGM-T载体中,得到载体pGM-T-ACR.分别将pET32a质粒和pGM-T-ACR质粒用限制性内切酶BamH Ⅰ和Xho Ⅰ双酶切,并将纯化的ACR基因亚克隆至pET32a中,获得重组表达质粒pET32a-ACR.将其转化E.coli BL21 IPTG诱导后,经SDS-PAGE、western blot分析鉴定,可见约34 ku的外源蛋白带.表明ACR基因在大肠杆菌中得到了表达.用Ni-NTA Agarose试剂盒进行蛋白纯化,获得纯化的ACR融合蛋白.  相似文献   

10.
应用特异性引物,从鸽新城疫F基因重组质粒pMD-18T-PPMV-1-F中PCR扩增F基因,用EcoRⅠ和NotⅠ分别对扩增产物和酵母表达质粒pPIC9K进行双酶切,将F基因定向克隆到pPIC9K的EcoRⅠ和NotⅠ位点,构建重组质粒pPIC9K-PPMV-1-F,对重组质粒鉴定后用SalⅠ酶切使其线性化,电击转化至感受态毕赤酵母GS115菌中,影印接种法筛选G418抗性菌株,提取酵母染色体DNA进行PCR鉴定,筛选出鸽新城疫F基因的高拷贝重组菌株。  相似文献   

11.
Pili of Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry were isolated and purified by sucrose-density-gradient centrifugation. Each serotype expressed only one type of pilus. The pili of the three serotypes had similar densities and were morphologically similar by electron microscopy. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, however, showed that they were slightly different in subunit molecular mass. Slide agglutination, immunodiffusion, and immunoblot tests were used to test for antigenic relationships between these pili and reference pili. Pili of serotype O78 were type 1, but pili of serotypes O1 and O2 were not, as once believed. However, pili of serotype O2 reacted positively with anti-type 1 serum in immunoblot assay, suggesting the presence of some common antigenic epitopes among these pili.  相似文献   

12.
Pilus proteins from Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry were compared with regard to their antigenic relatedness and partial amino acid sequences. Agglutination, immunodiffusion, and immunoblot assays with polyclonal antibodies to these pili showed that these pili not only share some common antigens but also contain antigens unique to each pilus. The partial amino-terminal amino acid sequences support our earlier findings that the pili are different but contain some structural homologies.  相似文献   

13.
The RNA genome of foot- and mouth disease virus strains A5 Westerwald and O1 Lausanne has been reverse-transcribed and cloned in lambdaphages or plasmids. Identification of cDNA-clones containing VP1-specific sequences was achieved by hybridization, restriction mapping, and sequence analysis. VP1-coding cDNA-fragments were subcloned into the expression vector pEX which led to synthesis of fusion proteins with beta-galactosidase. These fusion proteins reacted with anti-VP1 antibodies on a Western blot, but were not capable of inducing neutralizing antibodies to mice. This seemed to suggest a tertiary structure of the VP1-epitopes unlike those of native VP1. Other attempts are discussed to construct VP1-fusion proteins folding similarly to the native viral protein structure.  相似文献   

14.
为了探讨口蹄疫O型-亚洲1型二价灭活苗免疫接种羊后产生的O型抗体效价,采用不同免疫剂量和不同免疫时间免疫接种羊,应用正向间接血凝试验(IHA),检测其抗体消长规律.结果表明,羔羊母源抗体水平及维持时间与母羊抗体水平呈正相关,有效保护抗体能维持70 d左右;首免每只1 mL、2 mL同时免疫的4组间免疫抗体水平经方差分析差异不显著,首免不能产生有效的保护抗体水平;二免2 mL、2.5 mL不同时间免疫的4组,首免后15 d与首免后28 d进行二免产生的抗体经t检验差异极显著(P<0.01),首免后28 d二免的不同剂量组经方差分析差异不显著,有效抗体能维持约170 d,首免后15 d二免的免疫抗体水平最低;每只三免2 mL、3 mL的2个剂量组产生的有效抗体均能维持180 d,两组抗体经t检验差异不显著(P>0.05).  相似文献   

15.
Coupled synthetic peptides, representing the sequences of amino acids 130-160, 141-160 and 145-160 of foot-and-mouth disease virus O1K protein VP1, induced virus-binding and virus-neutralizing antibody response in guinea pigs, rabbits, and pigs. We also detected antibody response in guinea pigs after immunization with uncoupled peptides and in cattle with 21 aa-peptide-Keyhole-limpet hemocyanin (-KLH). The best results were obtained from 21 aa-peptide-KLH and 31 aa-peptide with or without KLH or thyroglobulin as carrier. Our preliminary results show the induction of virus-neutralizing antibodies to be obviously influenced by length of the peptide as well as by the kind of carrier and coupling.  相似文献   

16.
为了研究鹅FoxO1(forkhead box O1)基因的功能,根据GenBank已收录的鸡(Gallus gallus)、人(Homo sapiens)和小鼠(Mus musculus)等物种FoxO1基因序列的同源保守区域,设计特异性引物,利用RT-PCR技术克隆鹅FoxO1基因cDNA序列,并对基因序列进行了生物信息学分析。结果表明,成功克隆得到了鹅FoxO1基因cDNA序列,通过BLAST比对,鹅FoxO1基因与原鸡、人、小鼠的核苷酸序列同源性分别为97%、83%、82%,FoxO1基因在四川白鹅中表达水平总体表现为:皮脂>腹脂>腿肌>胸肌>肝脏。因此,FoxO1基因在多个组织中都有表达,且表达差异较大。  相似文献   

17.
表达O型口蹄疫病毒VP1蛋白,用于O型口蹄疫病毒的检测.以质粒T234/FMDV为模板,PCR扩增VP1基因片段,构建重组质粒pET-41b/VP1,转化表达菌BL21(DE3),IPTG诱导,SDS-PAGE凝胶电泳和Western blot进行分析检测,目的蛋白经镍离子亲和层析纯化,以纯化的目的蛋白包被,建立了间接...  相似文献   

18.
EAST1 (EnteroAggregative heat-Stable Toxin 1) is a 4.1 kDa toxin that was first detected in the enteroaggregative Escherichia coli (EAEC) strain 17-2 (O3:H2) isolated from the stools of a Chilean child with diarrhoea. Accordingly, EAST1 is thought to play a role in the pathogenicity of EAEC. The goal of this study was to obtain purified biologically active forms of two EAST1 variants (17-2 and O 42). Purified toxin samples were treated with protein disulfide isomerase (PDI) to ascertain the integrity of the disulfide bridges. Since EAST1 is often compared to STa (heat-Stable Toxin a), both purified EAST1 variants were tested for biological activity using the suckling mouse assay, the reference test for STa. A positive gut to body (G/B) weight ratio was not observed for any of the EAST1 preparations tested, although STa was active. Exposure of the purified toxins to T84 cell monolayers, an epithelial cell line derived from a human colon carcinoma, in modified Ussing flux chambers resulted in a rapidly attained and prolonged increase in short circuit current, a sensitive measure of net ion transport. Responses to 17-2 and O 42 variants were comparable in magnitude and inhibitable by bumetanide and DASU-02, indicating net anion secretion. The results demonstrate that EAST1 toxin stimulates anion secretion by T84 cell monolayers and it is sustained for the duration of toxin exposure.  相似文献   

19.
利用杆状病毒表达系统进行了口蹄疫病毒VP1基因在Sf9细胞中的表达研究。首先克隆了VP1基因片段.将pMD18-VP1质粒及杆状病毒转座载体质粒pFastBacⅠ分别用BamHⅠ及Hind Ⅲ酶切后,用T4 DNA连接酶连接。构建了重组质粒pFastBac-VP1;再将该重组质粒转化DH10Bac感受态细菌。在菌体内进行重组,并经三重抗性与蓝白斑筛选。得到杆状病毒重组质粒Bacmid-VP1;将Bacmid-VP1转染Sf9细胞.获得重组杆状病毒.并进行表达水平的检测。经SDS-PAGE和Western-blotting检测。结果表明,VP1蛋白在重组杆状病毒中获得表达。  相似文献   

20.
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