首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
为构建新孢子虫和弓形虫AMA1基因重组腺病毒,并分析其免疫原性,本试验根据新孢子虫和弓形虫AMA1基因序列的开放阅读框,设计新孢子虫和弓形虫交叉抗原AMA1基因通用引物,构建重组克隆质粒pMD18T-NcAMA1、pMD18T-TgAMA1及重组腺病毒穿梭质粒ADV4-Nc/TgAMA1,将ADV4-Nc/TgAMA1和骨架质粒pacAd5线性化后共转染293T细胞,包装Ad5-Nc/TgAMA1重组腺病毒,测定病毒滴度后,收集病毒液接种BALB/c小鼠,间接ELISA检测小鼠血清IgG抗体水平。结果显示,Nc/TgAMA1在Ad5-Nc/TgAMA1重组腺病毒中获得表达,测定Ad5-Nc/TgAMA1重组腺病毒滴度为109PFU/mL,接种BALB/c小鼠后,Ad5-Nc/TgAMA1接种组IgG抗体水平明显高于pVAX1-Nc/TgAMA1质粒组和PBS对照组。结果表明,构建的Ad5-Nc/TgAMA1重组腺病毒能诱导小鼠产生特异性体液免疫应答。本试验为新孢子虫和弓形虫交叉抗原AMA1基因重组腺病毒载体疫苗的研制奠定了基础。  相似文献   

2.
为构建牛源犬新孢子虫NcSRS2基因重组腺病毒,并分析其免疫原性,PCR扩增牛源犬新孢子虫NcSRS2基因,构建克隆质粒pMD18-T-NcSRS2、重组腺病毒穿梭质粒pCR259-NcSRS2及表达质粒Transpose-AdNcSRS2,脂质体介导转染QBI-HEK293细胞,包装重组腺病毒Ad5-NcSRS2,PCR检测重组腺病毒NcSRS2基因,IFAT和Western blotting检测NcSRS2基因在QBI-HEK293细胞中的表达,测定病毒滴度后,收集病毒液免疫BALB/c小鼠,间接ELISA检测小鼠血清IgG抗体水平.结果显示,扩增的牛源犬新孢子虫NcSRS2基因大小为1 227 bp,与GenBank中发表的NcSRS2( AF061249)核苷酸序列相似性为99%;重组腺病毒Ad5-NcSRS2在293细胞中包装成功,表达蛋白的相对分子质量为43 ku,具有较好的反应原性;测得重组腺病毒Ad5-NcSRS2滴度为109TCID50·mL-1,间接ELISA检测二免后3周BALB/c小鼠血清中IgG抗体效价达1 ∶ 2 048.本研究成功构建了具有良好免疫原性的重组腺病毒Ad5-NcSRS2,为牛源犬新孢子虫NcSRS2基因重组腺病毒载体疫苗的研制奠定了基础.  相似文献   

3.
试验旨在构建表达猪附红细胞体ENO基因的重组腺病毒并分析评价其免疫效果。将重组克隆质粒pMD-19T-ENO与腺病毒穿梭载体AdV4-GFP分别进行双酶切,构建重组腺病毒穿梭质粒AdV4-M/ENO;将经PacⅠ酶线性化后的重组腺病毒穿梭质粒AdV4-M/ENO转染293细胞,获得重组腺病毒Ad4-M/ENO,采用PCR和间接免疫荧光试验(IFTA)鉴定猪附红细胞体ENO基因在293细胞中的表达,再对293细胞进行培养,测定重组腺病毒的滴度;将30只BALB/c小鼠分为3组:重组腺病毒Ad4-M/ENO组、AdV4-GFP空载体对照组和PBS对照组,分别进行免疫接种,采用ELISA方法检测血清中猪附红细胞体IgG、IgG1、IgG2a抗体水平和IFN-γ、IL-4细胞因子水平,在三免2周后检测小鼠脾脏中CD4+和CD8+含量。结果显示,构建的重组腺病毒穿梭质粒AdV4-M/ENO目的基因片段大小为1 182 bp;重组腺病毒Ad4-M/ENO包装成功,能在293细胞中表达,滴度为1×109 PFU/mL。经重组腺病毒Ad4-M/ENO免疫后的BALB/c小鼠血清中IgG、IgG1、IgG2a抗体水平,IFN-γ、IL-4细胞因子水平及淋巴细胞亚群CD4+、CD8+含量均显著或极显著高于AdV4-GFP空载体对照组和PBS对照组(P<0.05;P<0.01)。结果表明,本试验成功构建了表达猪附红细胞体ENO基因的重组腺病毒,且该重组腺病毒能诱导小鼠产生特异性的体液免疫和细胞免疫应答反应。  相似文献   

4.
为了研究含有猪圆环病毒2型(porcine circovirus type 2,PCV2)的重组腺病毒作为基因工程疫苗的潜在应用价值,本试验根据GenBank中猪圆环病毒2型基因序列,设计了1对引物,用于猪圆环病毒2型ORF2基因的扩增。将目的基因T/A克隆后,亚克隆至腺病毒转移载体pShuttle-CMV,构建重组穿梭质粒pShuttle-CMV-ORF2。经PCR方法和限制性内切酶酶切法及测序证明该基因已成功连接后,重组腺病毒转移载体经PmeⅠ酶切线性化,在BJ5183细菌中与腺病毒骨架载体pAdEasy-1同源重组获得重组腺病毒质粒pAd-CMV-ORF2。经PCR方法和PacⅠ酶切方法及测序鉴定表明该重组腺病毒载体已构建成功。PacⅠ酶切线性化pAd-CMV-ORF2,脂质体法转染AD293细胞进行病毒的包装和扩增。PCR及RT-PCR、IFA、Western blotting检测目的基因及其表达。结果表明,本试验成功构建了重组腺病毒pAd-CMV-ORF2。3次噬斑试验纯化重组腺病毒,测得其TCID50为10-8.75/0.1 mL。将重组腺病毒接种SPF级雌性BALB/c小鼠,用ELISA抗体检测试剂盒检测特异性抗体水平。小鼠免疫试验测得其特异性抗体水平较高,为PCV2重组腺病毒基因工程疫苗的进一步研究打下基础。  相似文献   

5.
Diagnosis and treatment of Neospora caninum infection in a dog   总被引:1,自引:0,他引:1  
Neospora caninum, a protozoan organism, caused extensor rigidity of the pelvic limbs in a 12-week-old dog. Diagnosis was based on results of muscle biopsy, neuroelectrodiagnostics, serotesting, and cell culture. Indirect fluorescent antibody (IFA) titer to N caninum was 1:800 at time of admission and 1:3,200 after 4 and 6 weeks. A reciprocal IFA titer of 50 to N caninum was also found in the CSF. Serotesting for T gondii was negative. Treatment with clindamycin followed by sulfadiazine and trimethoprim did not change the pelvic limb extensor rigidity, but other signs of minor neurologic dysfunction improved.  相似文献   

6.
The main purpose of the present study was to investigate the occurrence of antibodies against T. gondii and N. caninum in captive maned wolves from Brazil, considering that little information is available at the literature about infections by these parasites in this wild animal. Serum samples were obtained from 59 maned wolves originated from six zoos and from one ecological reserve of the southeastern and midwestern regions of Brazil. To detect IgG antibodies against T. gondii, an ELISA protocol was used and the results were expressed as ELISA reactivity indexes (EI). Serology for N. caninum was carried out by indirect fluorescent antibody test (IFAT) and cut-off titers were established at 1:25 dilution. From the total of the analyzed samples, 44 (74.6%) were seropositive for T. gondii and only 5 (8.5%) for N. caninum. Seropositivity for T. gondii ranged from 0 to 100% in the seven different origin locals, with rates over 50% among the six zoos, whereas no positivity was found in the samples from ecological reserve. For N. caninum, seroprevalence varied from 0 to 50% in the different locals, with the highest rates also detected in zoos. Seroprevalence for T. gondii was strongly related with age, with rates significantly higher among adult wolves (91.7%) when compared to newborn or young animals. Seropositive samples for N. caninum were found predominantly in adult wolves. For both parasites, seroprevalence did not show a significant distinction in relation to gender. Although seroprevalence for T. gondii was significantly higher when compared to N. caninum in the Brazilian captive maned wolves tested, these findings reflect the great exposure of this species to T. gondii and, in lower extension, to N. caninum. Also, the present study demonstrated for the first time the presence of antibodies to N. caninum in wild life from South America.  相似文献   

7.
根据GenBank中MIC3基因序列设计1对引物,采用PCR技术从弓形虫GJS株基因组DNA中扩增微线体蛋白3(MIC3)基因片段,克隆到pMD18-T载体,经PCR、酶切及测序鉴定后,阳性重组质粒酶切并亚克隆到真核表达载体pcDNA3.1(+)后进行PCR、酶切及测序鉴定.重组质粒pcDNA3-MIC3肌肉注射免疫BALB/c小鼠,通过ELISA检测血清特异抗体;经腹腔攻击感染弓形虫GJS株速殖子,观察小鼠的生存时间.结果成功构建了pcD-NA3-MIC3质粒;免疫组小鼠血清检测到特异性抗体;攻击感染后免疫组小鼠平均存活时间较对照组明显延长.表明该核酸疫苗具有较好的免疫原性,能诱导小鼠产生良好的免疫保护作用.  相似文献   

8.
Diagnosis of Neospora caninum infection in dogs is based on serological assays such as the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assays (ELISA). This study evaluated two serological tests (IFAT and ELISA) for the detection of IgG antibodies to N. caninum in 300 serum samples of dogs through the optimization of cut off titers by using the two-graph receiver-operating characteristic (TG-ROC) curve. In addition, the identification of major cross-reactive antigens with Toxoplasma gondii was investigated by inhibition ELISA and immunoblotting (IB) assays. IFAT and ELISA results showed 74% agreement, with a good negative concordance (P(neg)=0.83), but a poor positive concordance (P(pos)=0.42). The great majority (86%) of sera with positive concordant results (IFAT+/ELISA+) recognized at least two out of three N. caninum immunodominant antigens, particularly the 29-32 and 35-37 kDa bands. Optimization of cut off titers in IFAT and ELISA was performed considering the reactivity to at least two out of three N. caninum immunodominant antigens as infection markers, obtaining a titer of 50 for IFAT and 200 for ELISA. Seropositivity to N. caninum was significantly associated with T. gondii-seropositive samples, particularly in ELISA (55.4%). Inhibition ELISA curves for N. caninum showed a partial heterologous inhibition, indicating some degree of cross-reactivity between N. caninum and T. gondii antigens. Inhibition IB assays showed a moderate heterologous inhibition for N. caninum antigens above 45-50 kDa. These results indicate that ELISA should be used critically when crude tachyzoite antigen preparations are employed, due to possible cross-reactivity with other related parasites as T. gondii. Also, the cut off dilution of 1:50 in IFAT showed to be the most appropriated for N. caninum serology in dogs. Therefore, we suggest that N. caninum immunodominant antigens, specially the 17 and 29-32 kDa proteins, should be selected markers in serological assays for canine neosporosis.  相似文献   

9.
A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.  相似文献   

10.
为了构建叉头框L2(Forkhead box L2,FOXL2)基因与绿色荧光蛋白(GFP)基因复制缺陷型腺病毒载体,试验将克隆的FOXL2基因与IRES-GFP片段通过酶切、纯化等方法共同连接到pShuttle-CMV载体中,再与pAdEasy-1腺病毒质粒在BJ5183大肠杆菌中进行同源重组,得到复制缺陷型AD-FOXL2腺病毒载体,再用PacⅠ酶线性化后转染HEK293细胞,观察绿色荧光表达,并测量病毒效价。结果表明:将AD-FOXL2腺病毒载体用PacⅠ酶线性化后,得到1个大于23 kb的大片段和1个4.5 kb的特异性小片段,证明同源重组成功;将所得的腺病毒载体转染HEK293细胞,可以观察到GFP的表达,证明包装成功,并测得病毒效价为1×10-8.61/0.1 mLTCID50。  相似文献   

11.
为建立牛新孢子虫和弓形虫的免疫学检测方法,并调查新疆部分地区牛新孢子虫和弓形虫的感染情况,本研究应用纯化的新孢子虫重组蛋白SRS2(NcSRS2)和弓形虫重组蛋白SAG2(TgSAG2)作为包被抗原,分别建立新孢子虫和弓形虫的ELISA和western blot血清学检测方法,并进行特异性和重复性试验,以其检测662份疑似样品,并与商品化试剂盒检测结果比较验证。特异性和重复性试验结果表明,建立的方法特异性强、重复性良好。采用建立的两种ELISA方法对662份临床样品的检测结果表明,新孢子虫和弓形虫的抗体阳性率分别为13.44%(89/662)和5.29%(35/662);与IDEXX试剂盒和永辉试剂盒的符合率分别为94.11%和95.92%。此外,western blot检测的新孢子虫和弓形虫抗体阳性率分别为5.14%(34/662)和3.17%(21/662);与建立的ELISA检测方法的符合率分别为91.69%和97.89%。本研究为分析奶牛流产的原因提供了一定的依据。  相似文献   

12.
Deer are considered important intermediate hosts for the coccidian parasites, Toxoplasma gondii and Neospora caninum. Antibodies to N. caninum and T. gondii were determined in sera of 42 mule deer (Odocoileus hemionus hemionus) and 43 black-tailed deer (Odocoileus hemionus columbianus) from Washington state, USA, using direct agglutination test with specific antigens. A titer of 1:25 was considered diagnostic for both parasites. N. caninum antibodies were found in 7 of 42 mule deer and 8 of 43 black-tailed deer. T. gondii antibodies were found in 14 black-tailed deer but not in any of the mule deer. This is probably the first report of seroprevalence of N. caninum in these hosts.  相似文献   

13.
利用腺病毒表达系统表达猪圆环病毒2型(porcine circovirus type 2,PCV2)的ORF2基因与T细胞表位(T cell epitope,TCE)基因,表达的融合蛋白具有反应原性,为研制PCV2新型疫苗奠定基础。以pMD18-T-ORF2、pMD18-T-TCE为模板,采用PCR方法扩增目的基因ORF2和TCE,以多肽接头(Gly4Ser)3为连接子,运用重叠延伸PCR技术将2段基因通过连接子(Gly4Ser)3进行融合连接。将融合基因定向克隆至腺病毒转移载体pShuttle-CMV构建重组质粒pShuttle-CMV-ORF2-TCE,将该重组质粒用PmeⅠ酶线性化后电转化大肠杆菌BJ5183感受态细胞(内含pAdEasy-1骨架质粒)进行同源重组获得重组腺病毒质粒pAd-ORF2-TCE。PacⅠ酶线性化pAd-ORF2-TCE质粒后转染AD293细胞包装病毒,重组腺病毒经3轮噬斑纯化后获得重组腺病毒rAd-ORF2-TCE,病毒滴度为1012.3 TCID50/mL。Western blotting及间接免疫荧光试验(indirect immunofluorecent assay,IFA)结果表明融合蛋白得到正确表达。  相似文献   

14.
Neospora caninum and Toxoplasma gondii are biologically and morphologically similar coccidians with canids as definitive hosts for N. caninum and felids for T. gondii. Feral chickens have been used as indicators of soil contamination with T. gondii oocysts because they feed from ground. In the present study we studied seroprevalence of N. caninum in free range chickens from different countries in America as an indicator of soil contamination due to N. caninum oocysts. Antibodies to N. caninum were found in sera of 524 (39.5%) of 1324 chickens using indirect fluorescent antibody test (IFAT, titer 1:25 or higher). Seropositive chickens from different countries were: 18.5% of 97 from Mexico, 7.2% of 97 from USA, 39.5% of 144 from Costa Rica, 71.5% of 102 from Grenada, 44% of 50 from Guatemala, 83.6% of 98 from Nicaragua, 58.1% of 55 from Argentina, 34.3% of 358 from Brazil, 62.3% of 85 from Chile, 11.2% of 62 from Colombia, 38.7% of 80 from Guyana, 18% of 50 from Peru and 21.7% of 46 from Venezuela. The results indicate widespread exposure of chickens to N. caninum.  相似文献   

15.
Sera from 68 nondomestic captive and free-ranging felids from southern Africa were tested for antibodies to Neospora caninum and Toxoplasma gondii by the indirect fluorescent antibody test. Four of the 68 (5.9%) serum samples were positive for antibodies to N. caninum, with titers ranging from 1:50 to 1:200. All other animals were negative for antibodies to N. caninum at a dilution of 1:50. Fifty of the 68 (74%) serum samples tested positive for antibodies to T. gondii, with titers ranging from 1:50 to 1:26,500. Four animals tested positive for antibodies to both N. caninum and T. gondii. None of these animals displayed clinical signs of disease. Results of this study indicate that nondomestic felids in southern Africa have been exposed to, and are likely infected with, N. caninum and T. gondii.  相似文献   

16.
【目的】 研究牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)E0和E2串联基因重组腺病毒作为基因工程疫苗的应用潜力。【方法】 采用PCR扩增、E0-E2基因融合并构建重组穿梭质粒pDC316-E0-E2,将其与AdMax腺病毒系统的骨架质粒共转染HEK293T细胞包装成重组腺病毒,通过Western blotting进行验证,并通过Reed-Muench法测定病毒滴度,通过肌内、皮下免疫接种小鼠后用ELISA方法及流式细胞检测进行免疫效果试验。【结果】 成功扩增到E0、E2基因目的片段,大小分别为681和1 122 bp,得到了完整的腺病毒Ad5-E0-E2;测定其滴度为1.1×1010 PFU/mL;Western blotting检测结果显示,Ad5-E0-E2外源基因在HEK293T细胞中表达,得到了与预期相符的目的条带(65 ku);ELISA检测结果表明,通过肌内和皮下注射Ad5-E0-E2均能产生较高的抗体水平;流式细胞检测显示首免、二免后肌内和皮下注射Ad5-E0-E2组CD4、CD4/CD8比值均极显著高于PBS对照组(P<0.01)。【结论】 本试验成功构建重组腺病毒Ad5-E0-E2,且具有较好的反应原性和免疫原性,能诱导机体产生针对BVDV的特异性抗体。  相似文献   

17.
应用PCR技术扩增牛新孢子虫NcSRS2基因,纯化PCR产物后与克隆载体pMD18-T Simple Vector连接,将PCR、酶切鉴定及测序分析正确的pMD-18T-NcSRS2重组质粒进行EcoRⅠ和XbaⅠ双酶切,克隆至相同酶切回收后的腺病毒穿梭载体pCR259中,再将PCR、酶切鉴定正确的pCR259-NcSRS2重组质粒转染293细胞,应用IF-AT和Western-blotting技术检测重组质粒在293细胞中的表达情况。结果显示,扩增的牛新孢子虫NcSRS2基因长度为1 227bp,与GenBank中发表的NcSRS2(AF061249)核苷酸序列同源性为99%,构建的pCR259-NcSRS2重组质粒在293细胞中得到瞬时表达,表达蛋白的相对分子质量为43 000,具有较好的反应原性。本试验为新孢子虫病腺病毒载体疫苗的构建奠定了基础。  相似文献   

18.
Toxoplasmosis and neosporosis have been recognized as economically important diseases with considerable impact on the livestock industry. Considering the scarce information on the occurrence of Toxoplasma gondii and Neospora caninum infections in sheep from Uberlandia, Minas Gerais State, Brazil, this study aimed to investigate the frequency of antibodies against these parasites in sheep sera from this region by using different serological methods. A total of 155 sheep serum samples were analyzed by the indirect fluorescence antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) for the detection of IgG against T. gondii and N. caninum. Seroreactivity by IFAT showed 80% of samples with titers between 512 and 2048 for T. gondii (cutoff ≥ 64) and 78% presenting titers between 50 and 200 for N. caninum (cutoff ≥ 50). Seroreactivity by ELISA showed 75% of samples with ELISA index (EI) between 2.0 and 3.0 for T. gondii (cutoff ≥ 1.3) and 54% presenting EI between 1.3 and 2.0 for N. caninum (cut off ≥ 1.3). Discordant results by both tests were analyzed by immunoblot, resulting in a total seropositivity of 61% for T. gondii and 23% for N. caninum, with 41% to T. gondii only, 3% to N. caninum only, and 20% to both parasites. There was a significant positive association between seropositivity to T. gondii and age over one year (P<0.001), but such association was not found for N. caninum infection. In conclusion, as T. gondii and N. caninum infections are simultaneously present in sheep flocks of this region, it should be emphasized the importance to carry out a regular monitoring of Toxoplasma infection due to its high prevalence, its zoonotic potential and induction of reproductive disorders leading to economic losses. For neosporosis, sheep farmers should be instructed about the presence of the parasite in the flock, its risk factors and potential abortifacient role in sheep. Differential flock management could be valuable tool to establish the association of serological positivity and reproductive disease induced by N. caninum in sheep.  相似文献   

19.
The enzyme-linked immunosorbent assay (ELISA) was used to examine cross-reactivity of Neospora caninum with Toxoplasma gondii and Hammondia heydorni. Anti-T. gondii mouse and cat sera cross-reacted with N. caninum soluble antigen (NLA), but not with the recombinant surface antigen (NcSRS2). Anti-H. heydorni dog sera showed no cross-reactivity with either the NLA antigen or the NcSRS2. Lack of cross-reactivity between anti-H. heydorni sera and N. caninum antigens, and the cross-reactivity of anti-T. gondii sera with the NLA suggest that N. caninum has common antigens to T. gondii except for NcSRS2 based on serology. In light of several studies suggesting a closer relationship between N. caninum and H. heydorni than with T gondii, examination of serological cross-reactivity with N. caninum may be necessary to further classify the parasites in addition to molecular and morphological studies and clarification of the life cycle.  相似文献   

20.
Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Romania and even in Europe. During 2007-2010, 735 serum samples were collected from dairy goats located in 4 historical regions (Cri?ana, Maramure?, Transylvania and Muntenia) of Romania. Sera were analyzed for T. gondii and N. caninum antibodies (IgG type) by enzyme-linked immunosorbent assay (ELISA) using two commercial kits (Chekit Toxotest Antibody ELISA and Chekit Neospora caninum Antibody ELISA; Idexx-Bommeli, Switzerland). Three hundred and eighty-eight out of 735 (52.8%) goats presented T. gondii antibodies and 12 out of 512 (2.3%) goats had N. caninum antibodies. The high seroprevalence of T. gondii suggests that infection with this parasite is common in dairy goats in Romania, and less common the infection with N. caninum. This is the first time that infection with N. caninum in goats has been reported in Romania and the first extended study on seroepidemiology of T. gondii.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号