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1.
为了建立梨形虫(Piroplasmida)和伊氏锥虫(Trypanosoma evansi)的双重PCR检测方法,试验根据梨形虫的18S rRNA基因和伊氏锥虫的kDNA基因设计两对特异性引物,以吕氏泰勒虫和伊氏锥虫阳性样品DNA为模板进行单重PCR和双重PCR,并对双重PCR的退火温度进行优化,对本研究建立并优化的双重PCR方法进行特异性试验、敏感性试验及临床样品的检测。结果表明:本研究建立的双重PCR方法能够扩增出350 bp和600 bp的特异性目的条带,而无浆体、肝簇虫、弓形虫和埃立克体样品均呈阴性,梨形虫和伊氏锥虫最低检测浓度分别为54.70 fg/μL和14.30 fg/μL,用本试验建立的方法对临床样品的检测结果与对照方法(巢式PCR)检测结果一致。说明本研究成功建立了灵敏、快速、简便、特异性高的双重PCR检测方法,能够用于梨形虫和伊氏锥虫的临床检测及流行病学调查。  相似文献   

2.
奶牛无浆体病PCR诊断方法的建立及应用   总被引:3,自引:0,他引:3  
利用边缘无浆体(Anaplasma marginale)高度保守的msp5基因,建立了奶牛无浆体病PCR诊断方法。特异性试验表明与牛巴贝斯虫、双芽巴贝斯虫、温氏附红细胞体、大肠杆菌、金黄色葡萄球菌和牛白细胞DNA无交叉反应;敏感性试验表明可检测到约200个感染红细胞。利用该方法对黑龙江省西部多个养牛场送检的140份血样进行检测,其中曾出现过高热、气喘、流涎和贫血等临床症状的"无名高热"奶牛血样95份、无临床症状奶牛血样45份,结果有上述临床症状奶牛PCR血样阳性率为44.2%,无症状奶牛血样PCR阳性率为13.3%。从而证实无浆体是引起奶牛"无名高热"的病原之一。  相似文献   

3.
犬附红细胞体PCR检测方法的建立   总被引:2,自引:0,他引:2  
目的 步建立犬附红细胞体PCR检测方法。方法 据已发表的附红细胞体基因序列,设计了一对特异性引物,以犬附红细胞体基因组DNA和附红细胞体可疑病犬样品DNA为模板,聚合酶链式反应(PCR)扩增,扩增产物经克隆测序分析。结果 CR扩增产物大小为541bp,序列分析表明与GenBank数据中发表的序列一致,表明这套引物成功扩增出目的基因序列,但正常犬血样品DNA和弓形虫、伊氏锥虫、吉氏巴贝斯虫、犬细小病毒、犬瘟热的DNA样品都不能扩增出目的基因片段。结论 研究建立的PCR方法可以用于犬附红细胞体的检测,为犬附红细胞体病的诊断及分子流行病学的调查提供了新的手段。  相似文献   

4.
犬附红细胞体PCR检测方法的建立与应用   总被引:1,自引:0,他引:1  
根据Genbank中已经发表的犬附红细胞体基因序列设计合成一对特异性引物,通过聚合酶链式反应(PCR)扩增出一条与目的片段大小一致,约630bp的基因片段,建立了犬附红细胞体PCR快速检测方法。研究结果表明该方法只能从犬附红细胞体中扩增出约630bp的基因片段。敏感性试验表明该方法最低可检测到10pg的DNA。利用该方法对临床上12例疑似犬附红细胞体血样进行检测,检出率75%,而直接镜检的阳性检出率仅为66.7%。  相似文献   

5.
奶牛附红细胞体感染PCR诊断方法的建立   总被引:8,自引:1,他引:8  
为建立特异、敏感、快速的奶牛附红细胞体感染诊断方法,该研究根据本实验室已测得的奶牛附红细胞体16S rRNA基因序列,设计1对种特异性引物,建立了奶牛附红细胞体的PCR诊断方法。特异性试验和敏感性试验结果表明,该诊断方法与猪肺炎支原体、鸡毒支原体、大肠杆菌、肠道沙门氏菌、葡萄球菌、鸡艾美耳球虫、牛双芽巴贝斯虫无交叉反应,能检测的奶牛附红细胞体最低DNA量为0.154fg,同时能检测出在4℃存放长达3个月的血样。通过临床血样检测,证明该方法可用于本病的早期诊断。  相似文献   

6.
根据牛边缘无浆体表面蛋白4的保守基因序列设计特异引物AMOC9/AMOC5、AMOC10/AMOC12和特异性探针MP,首次建立了牛边缘无浆体的实时荧光PCR检测方法,检测DNA的最低限度为200 fg。对中央无浆体、绵羊无浆体、牛巴贝斯虫、双芽巴贝斯虫、羊莫氏巴贝斯虫、山羊泰勒虫、温氏附红细胞体、东方巴贝斯虫、刚地弓形虫和伊氏锥虫进行检测,无荧光检测信号。本研究用所建立的方法检测采自江苏和哈尔滨的180份抗凝血(奶牛和肉牛),其阳性率为8.9%。结果表明,建立的实时荧光PCR检测牛边缘无浆体的方法具有较高的特异性和敏感性,可用于牛边缘无浆体病的流行病学调查、检疫和监测。  相似文献   

7.
以人工感染伊氏锥虫的小鼠血液涂片为抗原,建立了IFA试验检测马骡伊氏锥虫抗体的方法,并对伊氏锥虫病马、同群马、健康马、非伊氏锥虫病马血清作了检测。伊氏锥虫病马和无症状同群马的抗体阳性率分别为97%(33/34)和12%(18/150);25匹健康马血清伊氏锥虫抗体均为阴性;84份非伊氏锥虫病马血清的IFA试验均为阴性,未出现交叉反应。多数病马发病一周内的血清IFA试验即为阳性。3匹病马血清抗体消长动态观察结果表明,病马于治疗后110天,血清IFA试验仍为阳性。本试验表明,IFA试验检测马骡伊氏锥虫抗体,敏感性高、特异性强,对无症状的感染马也能检出,可用于本病的早期诊断和血清流行病学调查。  相似文献   

8.
温氏附红细胞体PCR检测方法的建立   总被引:1,自引:1,他引:0  
本研究旨在建立1种快速准确检测温氏附红细胞体感染的分子生物学诊断方法。根据温氏附红细胞体的16S rRNA基因参考序列的保守区,利用软件Primer Premier 5.0设计合成了1对特异性引物,对温氏附红细胞体的基因组DNA进行PCR检测。结果表明,扩增出1段985bp的DNA序列,EcoRⅠ酶切鉴定得到2条500bp左右的条带,与预期结果一致,说明该方法扩增出了温氏附红细胞体的特异性条带。通过敏感性、特异性、重复性和临床样品检测试验证明,该方法具有特异、灵敏、快速的优点。结果提示,所建立的方法具有较高的特异性和灵敏性,可用于牛附红细胞体病诊断和流行情况监测。  相似文献   

9.
猪附红细胞体PCR检测方法的建立和初步应用   总被引:22,自引:1,他引:22  
基于猪附红细胞体广东株16S rRNA基因的序列特点,设计合成种特异性引物,建立了猪附红细胞体PCR检测方法。该方法能特异性扩增523bp的猪附红细胞体16SrRNA基因片段,而对猪丹毒杆菌G4T10株、猪链球菌STl71株、多杀性巴氏杆菌E0630株、猪胸膜肺炎放线杆菌、猪肺炎支原体、鸡毒支原体和猫血巴尔通氏体CA株的基因组DNA没有扩增带出现。对猪附红细胞体基因组DNA的最小检测量为160pg。通过对38份临床样品的检测,8份为猪附红细胞体感染阳性,其余为阴性。结果表明,建立的PCR检测方法具有极高的敏感性和特异性,可用于急性猪附红细胞体病和临床健康带菌猪的诊断。  相似文献   

10.
奶牛附红细胞体的分类鉴定及诊断方法的建立   总被引:5,自引:0,他引:5  
为了从分子水平上确定奶牛附红细胞体(E.wenyoni)的分类学地位及建立奶牛附红细胞体感染诊断方法。本研究通过利用原核生物16S rRNA基因通用引物,对分离得到的奶牛附红细胞体(广西株,E.wenyoni-GX)进行16SrRNA基因的克隆及测序。并建立系统发育进化树;同时根据测序结果设计诊断引物,建立奶牛附红细胞体感染的PCR诊断方法。结果扩增出长约1.5kbp的奶牛附红细胞体的16SrRNA基因片段;特异性试验和敏感性试验表明。所建立的PCR方法与常见支原体、细菌及原虫元交叉反应,能检测奶牛附红细胞体最低DNA量为0.145fg。通过试验结果分析,建议将奶牛附红细胞体这类血营养菌划归入支原体科、支原体属;同时,所建立的PCR诊断方法是特异、敏感、快速的,可应用于临床检测。  相似文献   

11.
为了从分子水平上证实奶牛附红细胞体的存在及研究其分类学地位,利用原核生物16S rRNA基因通用引物对分离纯化的疑似奶牛附红细胞体进行16S rRNA基因的PCR扩增及克隆测序。结果扩增出长约1.5 kb的目的片段,测序结果表明:目的片段长度为1 439 bp,其核苷酸序列与国外已发表的牛温氏附红细胞体(E.wenyoni)的16SrRNA基因片段同源性高达97.1%,暂称为中国广西株(E.wenyoniCGX)。系统发育进化树显示:E.wenyoni和其他血营养菌在系统进化关系上组成了一个大的进化分支,与支原体科、支原体属的病原最接近(75%),而与立克次体科的病原较远(55%)。分析结果支持了Nei mark等和Messick等提出的将这类血营养菌划归支原体科、支原体属的建议。  相似文献   

12.
The mechanically transmitted haemoflagellate, Trypanosoma evansi causes 'surra', a wasting disease of domestic animals and is highly endemic in distribution in Southeast Asia. The detection of T. evansi is important for improving the epizootiological and animal health status of the region. The specificity and sensitivity of polymerase chain reaction (PCR) using oligonucleotide primers constructed from T. evansi repetitive DNA sequences were studied in the present investigation. Using the assay, it was possible to amplify template DNA of T. evansi derived from buffaloes, camels and horses to a threshold sensitivity level of 0.5 pg and to detect DNA from as few as five organisms in 10 microliters crude blood samples. Following experimental infection of calves with 5 x 10(5) T. evansi, positive signals could be observed as early as 12 h post-infection. DNAs from two common haemoflagellates of cattle, Babesia bigemina and Theileria annulata were not amplified with the primers.  相似文献   

13.
牛附红细胞体LAMP检测方法的建立   总被引:1,自引:0,他引:1  
为建立一种快捷、灵敏的牛附红细胞体检测方法,本研究根据GenBank上发表的16S rRNA基因(登录号:AF016546)序列设计合成2对LAMP特异引物,建立了检测牛附红细胞体环介导等温扩增(LAMP)方法,并优化了LAMP的各反应条件,进行了敏感性和特异性试验。LAMP扩增产物经电泳、显色鉴定。结果显示,LAMP方法扩增牛附红细胞体产物呈特征性梯状条带,显色反应呈现绿色荧光;敏感性检测最低浓度为25.6 fg/μL;特异性试验结果显示,牛附红细胞体检测管显色后呈阳性,而猪附红细胞体、牛新孢子虫、弓形虫及牛瑟氏泰勒虫等对照组均呈阴性,说明本研究建立的LAMP方法具有灵敏、特异、快速等优点,适合于牛附红细胞体的检测。  相似文献   

14.
A representative number of 217 camels (Camelus dromedarius) from different areas of western Rajasthan State, India, were examined from July 2002 to May 2003 for Trypanosoma evansi infection. The tests used were parasitological (wet blood film, WBF; stained thin blood smear, TBS), immunodiagnostic (double antibody sandwich enzyme linked immunosorbent assay for antigen detection, Ag-ELISA), and DNA amplification by polymerase chain reaction (PCR). These techniques were compared and the best efficiency was found for the last named (PCR). A prevalence of T. evansi infection was detected in 17.05, 9.67, 4.60 and 4.14% by PCR, Ag-ELISA, TBS and WBF with a sensitivity of 100, 56.75, 27.02 and 24.32%, respectively. PCR revealed a specific 227bp band in positive samples. The intensity of PCR bands was variable in different test samples depending upon the level of infection in the test samples. The history of intermittent fever, emaciation, oedema, poor body condition significantly correlated with positive serological status in ELISA as well as trypanosome DNA detection by PCR.  相似文献   

15.
A direct card agglutination test for Trypanosoma evansi, CATT/T. evansi based on the predominant variable antigen-type (pVAT) RoTat 1.2 was evaluated previously in the field in Isiolo District, Kenya. Sixteen out of 51 (31.4%) parasitologically positive camels were negative by the antibody detection test. In the present study, trypanosomes isolated from the camels were analysed in an attempt to determine the cause of the false negative results of CATT/T. evansi. A total of 20 field isolates comprised 16 stocks from camels that were negative by CATT/T. evansi, and 4 from CATT/T. evansi-positive camels. In addition, 15 known T. evansi and four T. brucei were used as reference. Purified DNA samples were tested using an established RoTat 1.2-based polymerase chain reaction (PCR) that yields a 488 bp product for the specific detection of T. evansi. Antibodies to RoTat 1.2 variant surface glycoprotein (VSG) were used in Western blotting to detect RoTat 1.2 VSG linear epitopes. Results of PCR and Western blot showed that the 16 stocks isolated from CATT/T. evansi-negative camels fell into three groups. In Group 1, both the RoTat 1.2 VSG gene and the VSG were absent in three stocks. In five trypanosome stocks in Group 2, the RoTat 1.2 VSG gene was detected, but Western blot was negative indicating absence of the expressed VSG. Five other stocks containing the RoTat 1.2 VSG gene were also in this group. The RoTat 1.2 VSG gene was detected and Western blot was positive in all four trypanosome stocks in Group 3. All four stocks from CATT/T. evansi-positive camels contained the RoTat 1.2 VSG gene and the expressed VSG. The reference T. evansi KETRI 2479 lacked the RoTat 1.2 VSG gene and there was no immune reactivity detected by Western blot. The rest of the reference T. evansi stocks examined contained the RoTat 1.2 VSG gene. All the four T. brucei samples examined were negative by PCR and Western blot. In conclusion, this study showed that the RoTat 1.2 VSG gene was absent from some T. evansi trypanosomes in Kenya.  相似文献   

16.
OBJECTIVE: To determine whether a polymerase chain reaction (PCR) assay could be used to detect Eperythrozoon wenyoni in the blood of cattle. DESIGN: Prospective study. ANIMALS: 95 cattle from various herds in Alabama and Georgia and 96 bulls enrolled in Auburn University's Alabama Beef Cattle Improvement Association Bull Test program. PROCEDURE: Blood samples were collected by means of venipuncture of the median caudal vein and submitted for a CBC and PCR assay. Blood smears were made immediately after blood collection and examined by means of light microscopy. RESULTS: Three of 95 cattle from herds in Alabama and Georgia and 5 of 96 bulls enrolled in the Bull Test program had positive PCR assay results. Organisms were seen in blood smears from only 5 of these 8 animals. Organisms were not seen in blood smears from any animals for which results of the PCR assay were negative. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a PCR assay may be an effective method for detecting E wenyoni infection in cattle and that the PCR assay may be a more sensitive test than evaluation of blood smears.  相似文献   

17.
为促进温氏支原体的深入研究,本试验建立了温氏支原体感染动物模型。选择6~8周龄健康雄性昆明种小鼠60只,随机分为A、B、C、D 4组,试验组(A、B、C)分别以不同方式感染温氏支原体,D组为对照组。结果表明,腹腔注射一定剂量高感染强度的牛红细胞悬液,同时注射免疫抑制剂地塞米松组(C组)表现为首现期出现早,且高峰期红细胞感染率高。应用悬滴镜检法和PCR诊断方法对感染小鼠血样进行鉴定,均符合温氏支原体特征。选择对照组小鼠和感染率高、临床症状较为明显的C组小鼠各10只,进行血液生理生化指标测定(RBC、WBC、Hb、TP、G、ALT、AST),结果呈现出与牛感染温氏支原体相同的规律。  相似文献   

18.
In the present study, a collection of 415 water buffalo serum samples originating from the north of Vietnam was used for evaluation of different diagnostic antibody detection methods available to detect infections with Trypanosoma evansi. The diagnostic sensitivity and specificity of a direct card agglutination test (CATT/T. evansi), an indirect card agglutination test (LATEX/T. evansi) and a newly developed antibody detection ELISA (ELISA/T. evansi) was calculated on the basis of parasitological results, obtained by mouse inoculation, and compared for all assays. The immume trypanolysis assay with the predominant T. evansi RoTat 1.2 variable antigen type was used as reference test for antibody presence. All parasitologically confirmed animals (n=8) were positive in all tests. Diagnostic specificity was highest in CATT/T. evansi (98%) followed by the ELISA/T. evansi (95%) and the LATEX/T. evansi (82%). Concordance of the variant specific immune trypanolysis test with the other tests was calculated and revealed that few (1-8%) false positive results were actually due to a specific reactions, and that LATEX/T. evansi and ELISA/T. evansi detected more immune trypanolysis positives than the CATT/T. evansi. It was concluded that, apart from the immune trypanolysis test, which is not generally applicable, ELISA/T. evansi with a 30% positivity cut-off and LATEX/T. evansi, thanks to their superior capacity of detecting T. evansi specific antibodies, would be suitable as epidemiological tools detecting both active infections and persisting T. evansi specific antibodies. The ELISA/T. evansi with a 50% positivity cut-off and the CATT/T. evansi on the other hand, seem more appropriate to detect true infected water buffaloes.  相似文献   

19.
The course of Trypanosoma evansi infection in coatis (Carnivora, Procionidae) was followed for 262 days. Parasites were detected in all infected animals from day 2 post infection until the end of the study. No correlation between temperature and parasitemia was observed. Animals of the infected group demonstrated depression, weakness, lethargy and pale mucous membranes. Indirect fluorescent antibody tests detected anti-T. evansi antibodies within 7 to 14 days post infection and showed high levels until the end of the experimental period. The persistent parasitemia in coati and their relative tolerance to clinical signs suggested that this species develops a chronic disease and plays an important role in the epidemiology of trypanosomosis due to T. evansi in enzootic regions.  相似文献   

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