类鼻疽伯克霍尔德菌groEL基因的克隆、原核表达及其蛋白的生物信息学分析

试验旨在对类鼻疽伯克霍尔德菌groEL基因进行克隆与原核表达，并对其表达蛋白进行生物信息学分析。提取该菌基因组DNA作为模板，参考GenBank中类鼻疽伯克霍尔德菌groEL基因序列，设计1对引物。通过PCR扩增得到大小为1 641 bp的groEL基因片段，将其连接至pMD19-T载体，构建pMD19-T-groEL重组质粒，经BamHⅠ和Hind Ⅲ双酶切鉴定正确后，构建重组质粒pET-28a（+）-groEL。将鉴定正确的pET-28a（+）-groEL质粒转化至E.coli BL21（DE3）感受态细胞中，经IPTG诱导表达，运用SDS-PAGE和Western blotting方法进行蛋白质鉴定，利用DNAMAN和BioEdit等软件进行生物信息学分析。结果发现，试验成功克隆了类鼻疽伯克霍尔德菌groEL基因并进行了蛋白表达，表达的融合蛋白大小约为64 ku，GroEL蛋白的分子式为C₄₅₁₀H₇₃₈₁N₁₆₄₁O₁₈₄₀S₅₂₁，原子总个数为15 893，消光系数为32 500，不稳定指数为40.31，亲水性平均值为0.901。GroEL蛋白二级结构中α-螺旋（Hh）、延伸链（Ee）、无规则卷曲（Cc）分别占48.71%、13.19%和38.10%。本试验结果为深入探究类鼻疽杆菌groEL基因的分子作用机理奠定了基础。     

牛卵形巴贝斯虫PCR检测方法的建立及初步应用

为建立牛卵形巴贝斯虫(B.ovata)快速检测方法,本研究根据GenBank中登录的B.ovata CCTη基因序列设计引物,建立了PCR检测方法。对该方法的最佳反应条件进行优化,并进行特异性、敏感性及临床样本检测试验。结果表明,建立的PCR方法扩增B.ovata CCTη基因片段大小为1 008 bp,与参考株序列同源性为100%。该方法对牛巴贝斯虫、牛双芽巴贝斯虫、牛瑟氏泰勒虫基因组DNA扩增结果均为阴性。最低可以检测样品中34个拷贝的DNA。通过对49份临床样本的检测,该方法比姬姆萨染色镜检阳性率高8.2%。本实验为B.ovata的诊断提供了一种特异、敏感的检测技术。     

羊源类鼻疽伯克霍尔德菌BPSL1467基因克隆、表达及其蛋白生物信息学分析

试验旨在克隆和表达羊源性类鼻疽伯克霍尔德菌（Burkholderia pseudomallei，B.pseudomallea）的BPSL1467基因，并对其表达的蛋白进行生物信息学分析。以羊源类鼻疽伯克霍尔德菌（BPHN1株）基因组为模板，参照GenBank中类鼻疽伯克霍尔德菌K96243标准株BPSL1467基因序列设计引物，PCR扩增获得目的基因片段，将所得片段与pET-28a（+）载体连接，构建pET-28a（+）-BPSL1467重组质粒。将鉴定正确的pET-28a（+）-BPSL1467重组质粒转化大肠杆菌BL21（DE3）感受态细胞，通过IPTG诱导表达，SDS-PAGE和Western blotting鉴定表达产物。使用DNAMAN、ProtParam、SOPMA和Protscale相关生物信息学软件对BPSL1467基因编码的氨基酸序列进行分析。结果显示，本试验成功克隆了462 bp的BPSL1467基因，诱导表达重组蛋白大小约为22 ku，主要以包涵体的形式存在。BPSL1467蛋白分子式为C₇₆₃H₁₂₀₉N₂₀₃O₂₁₇S₆，分子质量为16 890.58 u；其不稳定系数为33.95，属于稳定蛋白；理论等电点（pI）为8.85，为碱性蛋白；总平均疏水性（GRAVY）为-0.190，为亲水性蛋白。该蛋白的二级结构中以无规则卷曲和α-螺旋为主。本试验结果为深入研究羊源类鼻疽伯克霍尔德菌的BPSL1467基因的分子作用机理提供了参考依据。     

Experimental Burkholderia pseudomallei infection of pigs

Experimental infection with Burkholderia pseudomallei was successfully produced after a single intravenous challenge of 2-month-old pigs with a dose of 5.0 x 10(9) bacterial cells. Clinical, paraclinical and morphological findings of the infectious process and post-infectious immunity were examined up to day 30 post infection (p.i.). A transient and short hyperthermia accompanied by enhanced and longer demonstrated pulse frequency. An increased erythrocyte sedimentation rate and tachypnea were observed too after clinical examination. The infection starts with significant leucopenia, and a reduced number of alveolar and peritoneal macrophages which have been overcome in the latest intervals of infection. In contrast, the phagocytic activity of leucocytes was statistically increased during the course of infection and up to day 15 p.i. in the case of alveolar macrophages. Burkholderia pseudomallei was able to colonize the lungs during the whole experiment and was only present 3 days in the spleen and mesenterial lymph nodes (MLN). Significant antibody response was developed as early as day 7 p.i. Hyperaemia, haemorrhages and necrotic foci were found in the brain, liver spleen and MLN. Lung tissue was also hyperaemic, with formation of small abscesses and signs of catarrhal pneumonia. Data obtained in this study revealed that B. pseudomallei causes a chronic generalized infection in pigs, even after intravenous challenge.     

布鲁菌Cycling探针荧光定量PCR检测方法的建立

根据布鲁菌BCSP31基因序列设计布鲁菌通用检测引物和探针,建立了布鲁菌Cycling探针荧光定量PCR检测方法。以构建的含BCSP31基因的质粒标准品10倍递进稀释为模板检测其敏感性,结果显示,本方法能检测约10个拷贝的阳性质粒,且标准曲线的线性关系良好。用本方法检测5株不同种的布鲁菌以及猪大肠杆菌K99、巴氏杆菌C48-1、猪链球菌ST171、绿脓杆菌等4株对照菌。结果显示,5株不同种的布鲁菌均出现典型的"S"型扩增曲线,4株对照菌40个循环内均无CT值出现。用本方法和B4/B5-PCR方法对来自布鲁菌病流行地区3个不同牛场的40份血样、奶样和血清样进行平行检测。结果显示,本方法和B4/B5-PCR方法的结果符合率为80.0%。B4/B5-PCR检测为阳性的27份样品经本方法检测均为阳性;B4/B5-PCR检测为阴性的13份样本,经本方法检测,其中8份呈阳性,5份为阴性。本方法的敏感性明显高于B4/B5-PCR方法。试验表明,所建立的Cycling探针荧光定量PCR方法具有敏感、特异、稳定等特点,可用于布鲁菌感染的快速检测。     

羊源类鼻疽伯克霍尔德菌BPSS1512基因克隆、原核表达及其蛋白的生物信息学分析

为克隆羊源类鼻疽伯克霍尔德菌BPSS1512基因,并对其编码的蛋白进行生物信息学分析,以类鼻疽伯克霍尔德菌基因组为模板,参照GenBank中Burkholderia pseudomallei K96243株基因组DNA序列（登录号：NC_006351.1）设计引物,PCR扩增BPSS1512基因,构建重组质粒,SDS-PAGE和Western blotting分析其蛋白表达,DNAMAN等软件对BPSS1512基因编码的氨基酸序列进行分析。结果显示,PCR扩增成功得到1 425 bp的特异性条带,BamHⅠ和Hind Ⅲ双酶切后得到约为5 000和1 500 bp的条带,表明重组质粒pET-28a-BPSS1512构建成功,IPTG浓度为10 mmol/L,诱导时间8 h为最适宜的诱导条件。BPSS1512基因编码的蛋白质分子质量为53 ku,在包涵体中表达;在BPSS1512蛋白二级结构中,α-螺旋、延伸链和无规卷曲分别占24.05%、14.77%、61.18%,并且疏水性区域分布在-2.0~+2.4之间,说明BPSS1512蛋白具有较强的疏水性,本试验结果可为类鼻疽病的防制提供参考依据。     

Cloning,Prokaryotic Expression of BPSS1512 Gene in Goat Burkholderia pseudomallei and Bioinformatics Analysis of its Proteins

The experiment was aimed to study the clone and prokaryotic expression of BPSS1512 gene in goat Burkholderia pseudomallei and analyzed its proteins by bioinformatics. The geneome of Burkholderia pseudomallei was used as the template,and the primers were designed by DNAMAN software referring to genomic DNA sequence of Burkholoderia pseudomallei K96243 strain in GenBank (NC_006351.1).The BPSS1512 gene was amplified by PCR and the recombinant plasmid was constructed. Then the expressed protein was analyzed by SDS-PAGE and Western blotting, and the amino acid sequence encoded by BPSS1512 gene was analyzed by softwares such as DNAMAN.The results showed that the BPSS1512 gene was successfully cloned with the length of 1 425 bp,and the recombinant plasmid pET-28a-BPSS1512 was constructed. The optimum conditions for induction was that the IPTG was 10 mmol/L and 8 h for induction.The molecular weight of the protein was 53 ku,it was expressed as the form of inclusion body.In the secondary structure of BPSS15122 protein,alpha-helix,extended strand,and random coil were 24.05%,14.77% and 61.18%, respectively,and the hydrophobic core was distributed between -2.0 and +2.4 which indicated that the BPSS1512 protein was strong hydrophobicity.     

牛、羊布鲁菌多重PCR方法的建立与应用

根据布鲁菌属特异性基因BCSP31和布鲁菌种间特异性标志IS711插入序列,设计合成了3对引物,以牛种布鲁菌544A、104M和羊种布鲁菌16M基因组DNA为模板,通过优化反应条件,建立了可同时检测布鲁菌属、牛种布鲁菌和羊种布鲁菌的多重PCR方法。牛种布鲁菌可扩增出301和114 bp 2条带,羊种布鲁菌可扩增出301和253 bp 2条带,该方法对牛种布鲁菌544A和羊种布鲁菌16M混合DNA模板的最小检出量为100 pg,对大肠杆菌O157∶H7、小肠结肠炎耶尔森菌等15种参照菌的核酸扩增结果均为阴性。应用该方法对吉林省某牛场的106份粪便进行检测,虎红平板凝集试验作对照,结果PCR检测9份为阳性,且全为牛种布鲁菌阳性,对应的虎红平板凝集试验也为阳性。结果表明,建立的多重PCR方法具有良好的敏感性和特异性,为布鲁菌病的鉴别诊断提供了一种分子检测工具。     

Species-specific PCR assay for the detection of Babesia odocoilei

We developed a PCR assay for the detection of Babesia odocoilei based on the 18S rRNA gene. Multiple specimens of B. odocoilei were examined, and the assay consistently produced a small specific PCR product of 306 bp. The PCR assay was also challenged with DNA from 13 other Babesia species and 2 Theileria species, originating from 10 different host species; however, nonspecific DNA amplification and multiple banding patterns were observed, and the amplicon banding patterns varied between different isolates of the same species. Sensitivity was determined to be 6.4 pg of DNA, and an estimated 0.0001% parasitism. This assay can be utilized for species-specific differential detection of B. odocoilei.     

Serodiagnosis of Burkholderia mallei infections in horses: state-of-the-art and perspectives

Burkholderia mallei causes glanders or farcy in solipeds, a disease that must be reported to the OIE (Office International des Epizooties, Paris, France). The number of reported outbreaks has increased steadily during the last decade. Serodiagnosis is hampered by the considerable number of false-positives and -negatives of the internationally prescribed tests. The major problem leading to low sensitivity and specificity of complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e. crude preparations of whole cells. Future perspectives for the development and evaluation of serological test kits using well-characterized single antigens are discussed in the light of recent molecular research on B. mallei and the closely related saprozoonotic agent B. pseudomallei.     

A multiplex PCR for simultaneous detection and differentiation of North American serotypes of bluetongue and epizootic hemorrhagic disease viruses

In the present study, a multiplex RT-PCR-based assay for simultaneous detection and differentiation of North American serotypes of bluetongue (BT) virus (BTV) and epizootic hemorrhagic disease (EHD) virus (EHDV) in cell culture and clinical samples was developed. Two pairs of primers (B1 and B4) and (E1 and E4) were designed to hybridize to non-structural protein 1 (NS1) genomes of (BTV-11) and (EHDV-1), respectively. The multiplex PCR-based assay utilized a single tube-PCR amplification in which EHDV and BTV primers were used simultaneously in a multiplex format. The BTV primers generated a 790 base pair (bp) specific PCR product from RNA samples of North American BTV serotypes 2, 10, 11, 13 and 17; whereas EHDV serotypes 1 and 2 or total nucleic acid extract from non-infected baby hamster kidney (BHK) cells failed to demonstrate the 790bp specific BTV PCR product. Likewise, the EHDV primers produced a 387bp specific PCR product from RNA samples of EHDV serotypes 1 and 2, but not from BTV serotypes 2, 10, 11, 13, 17 or from total nucleic acid extract of BHK cell controls.Two pairs of nested primers (B2 and B3) and (E2 and E3), internal to the annealing sites of primers (B1and B4) and primers (E1 and E4), produced a 520bp specific BTV and a 224bp specific EHDV PCR product from BTV and EHDV first amplification products, respectively. These nested amplifications increased the sensitivity of the PCR assay and confirmed the specificity of the first amplified EHDV or BTV PCR products. The described multiplex RT-PCR-based assay could be used to facilitate rapid detection and differentiation of North American BTV and EHDV serotypes and to provide a valuable tool to study the epidemiology of these orbivirus infections in susceptible animal populations.     

猪博卡病毒实时荧光定量PCR检测方法的建立

根据GenBank公布的猪博卡病毒(PBoV)序列,通过VP1/2基因设计引物和Taq Man探针建立实时荧光定量PCR检测方法。建立的方法与PPV、PRRSV及PCV均无交叉反应,具有较高特异性,在107 copies/mL～101 copies/mL模板范围内具有良好的线性关系,所制作的标准曲线相关系数为0.997,最低可检测到101copies/mL的阳性质粒。说明所建立的PBoV实时荧光定量PCR检测方法具有灵敏度高、特异性好和精确性高等优点。     

A new Brucella canis species-specific PCR assay for the diagnosis of canine brucellosis

Brucellosis is a zoonotic disease that is transmitted from animals to humans, and the development of a rapid, accurate, and widely available identification method is essential for diagnosing this disease. In this study, we developed a new Brucella canis species-specific (BcSS) PCR assay and evaluated its specificity and sensitivity. A specific PCR primer set was designed based on the BCAN_B0548-0549 region in chromosome II of B. canis. The PCR detection for B. canis included amplification of a 300-bp product that is, not found on other Brucella species or, genetically or serologically related bacteria. The detection limit of BcSS-PCR assay was 6 pg/μl by DNA dilution, or 3 × 10³ colony-forming units (CFU) in the buffy coats separated from whole blood experimentally inoculated with B. canis. Using the buffy coat in this PCR assay resulted in approximately 100-times higher sensitivity for B. canis as compared to detect directly from whole blood. This is the first report of a species-specific PCR assay to detect B. canis, and the new assay will provide a valuable tool for the diagnosis of B. canis infection.     

化脓隐秘杆菌TaqMan实时荧光定量PCR检测方法的建立

本试验旨在建立检测化脓隐秘杆菌(Arcanobacterium pyogenes,A.pyogenes)特异、灵敏的TaqMan实时荧光定量PCR检测方法。根据GenBank公布的化脓隐秘杆菌溶血素(pyolysin,PLO)基因高保守序列,设计特异性引物和探针建立检测体系,用于化脓隐秘杆菌的快速检测,并对该方法的特异性和灵敏度进行检测。结果显示,本试验建立的TaqMan实时荧光定量PCR方法仅对化脓隐秘杆菌的检测结果为阳性;该方法最低检测DNA浓度为77.6 fg,最低检测细菌浓度为63 CFU/mL。采用本研究建立的方法检测23份林麝临床病例样品,共鉴定出16株化脓隐秘杆菌,与API Coryne生化鉴定方法的结果相同。本研究为化脓隐秘杆菌的检测提供了一种灵敏、特异、快速的检测方法,其可用于化脓隐秘杆菌的诊断和流行病学调查。     

Establishment of TaqMan Real-time PCR Assay for Detection of Arcanobacterium pyogenes

The study was aimed to establish a specific and sensitive TaqMan Real-time PCR assay for detection of Arcanobacterium pyogenes (A.pyogenes).Based on the conservative sequence of pyolysin (PLO) gene of A.pyogenes published in GenBank, specific primers and TaqMan probes were designed. The TaqMan Real-time PCR assay was established, and the specificity and sensitivity were tested.The specificity test results showed that only A.pyogenes exhibited typical curves.The detection sensitivity of this assay was 77.6 fg genomic DNA per 20 μL reaction, and 63 CFU/mL for pure cultures.16 out of 23 clinical samples were positive detected by the TaqMan Real-time PCR assay, which were consistent with API Coryne identification.The TaqMan Real-time PCR assay developed in this study was specific and sensitive for detection of A.pyogenes, and it could be used for identification and epidemiological investigation of A.pyogenes.     

人多形核白细胞杀灭类鼻疽杆菌的电镜观察

将类鼻疽杆菌纯培养物加入入脱纤血液中，置37℃水浴中模仿菌血症条件，分离含菌多形核白细胞（PMN）并进行电镜观察，结果表明，细菌吞入期其形态完整，吞噬全和菌体大小一致，随着杀灭功能的进行，天噬体变得很大，其内的细菌呈松散状，形态结构发生很大改变，可杀灭作用的后期，于吞噬全内仅见残留的细菌碎片，由此说明，健康入PMN非但不是类鼻疽杆菌潜藏的场所，而且能将其杀灭。     

犬细小病毒环介导等温扩增快速检测方法的初步建立

为建立犬细小病毒(CPV)环介导等温扩增(LAMP)检测方法,实现CPV的早期快速诊断,本研究根据GenBank登录的CPV VP2基因序列,在其序列保守区域设计LAMP引物,利用CPV基因组DNA为模板进行扩增。结果表明:LAMP方法检测灵敏度达到10-1TCID50/mL;并且与其它细小病毒等无特异性扩增,表现出良好的特异性。与PCR技术相比,LAMP法操作更加简单方便,更适合基层和实验室的快速检测。     

羊痘病毒实时荧光定量TaqManPCR检测方法的建立

参照羊痘病毒（CaPV）P32的基因序列，设计合成了2套引物和1条探针，建立了实时荧光定量PCR技术，对细胞培养物、皮肤丘疹、痂皮等组织病料中的GPV进行了特异性检测和敏感性试验。结果显示，用300nmol／L引物浓度和200nmol／L探针浓度，获得的CT值较小，而△Rn最大；可检测到相当于0．1TCID50的病毒DNA；制作的标准曲线中各浓度范围内有极好的线性关系且线性范围宽，相关系数为0．9995以上；组内和组间试验重复性的变异系数分别为2．3％和3．4％；与常规的PCR相比较，该方法具有快速、特异、敏感、可定量，可同时检测大量样品等优点。表明，荧光TaqMan PCR是一种检测CaPV的良好方法，可对组织病料中低含量的CaPV或持续带毒宿主进行准确检测。     

肝螺杆菌LAMP快速检测方法的建立及初步应用

根据肝螺杆菌fla B基因保守区域设计一组特异性引物,经过条件优化、特异性和敏感性分析,成功建立了肝螺杆菌LAMP快速检测方法。结果显示,建立的LAMP扩增方法仅能检测出肝螺杆菌,其他常见细菌未见特异性扩增。检出肝螺杆菌最低模板量为86.9fg/L,是普通PCR所需模板量的1/10。本研究建立的LAMP快速检测方法具备操作简单、特异性好、灵敏度高的优点,结果易于观察,对仪器设备要求低,适宜推广应用。     

应用TaqMan荧光定量PCR快速检测鹿血中副结核分枝杆菌

为建立快速检测鹿血中副结核分枝杆菌(Mycobacterium avium subsp. paratuberculosis,MAP)的荧光定量PCR方法,本研究根据GenBank中登录的MAPf57基因序列设计并合成引物及探针,并检测该方法的特异性和敏感性。试验结果显示,该方法具有良好的特异性,对MAP的检测灵敏度可以达到单个菌细胞。对长春地区采集的549份血清样品进行检测,结果显示阳性血清101份,阳性率达到18.4%。本研究结果表明,荧光定量PCR用于动物性产品MAP的检测具有快速、准确的特点。