共查询到18条相似文献，搜索用时 203 毫秒
1.
丝状霉形体丝状亚种SC型脂蛋白LppQ基因的序列分析 总被引：2，自引：0，他引：2
根据基因库发表的丝状霉形体丝状亚种SC型(MmmSC)脂蛋白LppQ基因序列设计引物，采用PCR对国内MmmSC分离株HVRI-X株的脂蛋白LppQ基因进行扩增，将扩增产物与pMDl8-T载体连接并测序。核苷酸序列比较结果显示，HVRI-X株的LppQ基因序列与基因库发表的核苷酸序列同源性为99．8％；由其推导的氨基酸序列同源性为99．3％。 相似文献
2.
根据已发表的丝状支原体丝状亚种SC型（MmmSC）脂蛋白Q（LppQ）基因序列设计并合成一对引物，利用PCR扩增方法，从我国不同省区的MmmSC分离株HVRI—X、BenI、QingI、MuI和模式株PG1中获得了LppQ基因1303 bp的片段，将该片段克隆到PMD18-T载体上，通过对所得到的重组质粒进行酶切分析、PCR鉴定，证明得到了含有目的基因片段的阳性重组质粒。采用Sanger’s双脱氧末端终止法对插入片段进行核苷酸序列测定，获得了HVRI-X、Ben Ⅰ、oing Ⅰ、Mu Ⅰ株和模式株PG1 LppQ基因核苷酸序列。核苷酸序列比较结果显示，国内4个MmmSC分离株与GenBank公布的LppQ基因核苷酸序列同源性均在99．7％以上，氨基酸序列同源性均在99％以上；与模式株PG1的核苷酸序列同源性在99．7％以上，氨基酸序列同源性均在99．3％以上。，国内4个MmmSC分离株之间的核苷酸序列同源性均在99．7％以上，氨基酸序列同源性均在99．3％以上。对HVPI X株LppQ基因氨基酸亲私陛和蛋白表面可能性进行了分析，证实LppQN末端富含亲水氨基酸，比C末端更有可能定位在蛋白表面。 相似文献
3.
4.
丝状支原体丝状亚种SC型是A类烈性传染病牛传染性胸膜肺炎的病原体。脂蛋白LppC是重要的免疫优势抗原,LppC基因是MmmSC的特异性基因。本研究通过PCR方法,扩增MmmSC标准株PGI的LppCN末端基因。将该序列克隆到pMDT-18载体上并测序,用pET32a为载体构建重组质粒进行诱导表达。LppCN末端基因长度为644bp,将其与NCBI上发布的Afade株、欧洲群代表株L2比较,它的核酸序列同源性为100％,表明LppC基因在种内高度保守。原核表达结果得到大小为45ku的目的蛋白,用Ni-NTA系统进行纯化得到高纯度的蛋白。Westernblot结果表明,重组蛋白能与牛传染性胸膜肺炎阳性血清反应,具有免疫学活性,为进一步与LppQ融合表达奠定基础。 相似文献
5.
建立了一个可以识别丝状支原体丝状亚种SC生物型（MmmSC)的PCR方法。根据丝状支原体丝状亚种SC生物型（MmmSC)相关核苷酸序列，设计合成了MC1、MC2和SC1、SC2两对引物。MC1、MC2是一对簇特异性引物，用于鉴别丝状支原体族6个成员，对MmmSC、MmmLC扩增出与预期结果相符的462bp片段；而SC1、SC2是针对MnnSC的一对特异性引物，只能对MmmSC扩增出277bp的片段，经过VspI、Bsp143I和Dral三种限制性内切酶鉴定与预期结果相符，而不能扩增出MmmLC型Y－goat代表株，说明具有非常好的特异性。对MmmSC进行的敏感性试验显示SC1、SC2引物能够检测到100个CFU，具有非常高的敏感性。 相似文献
6.
收集了6个来自不同地方中国历史流行的丝状支原体丝状亚种SC型（Mycoplasma mycoides subsp．MycoidesSC，MmmSC）毒株与PG1、Y—goat进行分子特征比较。全茵体蛋白电泳与PG1完全相同，而与Y-goat不同；PCR结果显示6个中国分离株与PG1、Y-goat都没有缺失8．84kb片段；LppB全基因序列比较发现与PG1同源性达99％，而与Y—goat同源性很低；多位点基因序列类型（Multilocus sequence types，MST）分析显示与非洲澳大利亚群完全相同。以上证据显示中国CBPP流行株应归属于非洲澳大利亚群。 相似文献
7.
番鸭呼肠孤病毒ZJ99株σC蛋白基因的克隆与序列分析 总被引：1，自引：0，他引：1
参考已发表的番鸭呼肠孤病毒(mDRV)的S4序列设计了S4对扩增σC蛋白基N的引物，对mDRV ZJ99株的RNA抽提物进行RT—PCR扩增，获得了特异性的扩增片段。将PCR产物克隆测序，序列经同源性比较，发现mDRV ZJ99株σC蛋白基N序列与福建MW9710株对应基N的同源性为99．5％，与法国89026株对应基因的同源性为94．2％，与法国89330株对应基因的同源性为95．0％；相应的氨基酸序列同源性分别为98．9％、94．1％、93．7％。基于σC基因及其推导氨基酸序列的蛋白质结构及物理化学性质预测结果，与国外学者对mDRV σC蛋白的报道相似。 相似文献
8.
H5N1亚型禽流感病毒新疆株NS基因的克隆和序列分析 总被引：1，自引：0，他引：1
根据已发表的H5N1禽流感病毒NS基因全序列设计了1对引物，对4株禽流感病毒新疆株的NS基因进行了RT—PCR扩增，并将其克隆到pMD18-T载体上，分别获得了全长为817、851、854、854bp的全基因序列。序列分析结果表明，新疆毒株间的核苷酸同源性为97．8％～98．9%，氨基酸同源性为96．5％～98．7％，与广东、香港和东南亚等不同地区的11个毒株比较，同源性为90．0％～99．4％；与来自野禽、猪等不同种类的11个流感毒株比较，同源性为81．4％～99．3％。系统进化树分析表明，新疆株独立分支。 相似文献
9.
为鉴别牛支原体(Mycoplasma bovis)与丝状支原体丝状亚种SC(M.mycoides subsp.mycoides SC),本实验通过优化M.bovis特异性引物pMB81-1/pMB81-2s和MmmSC特异性引物SC1/SC2的退火温度,建立了鉴别M.bovis和MmmSC的双重PCR检测方法。该方法能够分别由M.bovis和MmmSC扩增得到528bp和270bp片段。敏感性试验结果显示该方法检测M.bovis和MmmSC培养物的最低浓度分别为106cfu/mL和105cfu/mL。特异性试验结果显示,该方法对无乳支原体代表株PG2、丝状支原体丝状亚种LC型代表株Y-goat、山羊支原体山羊肺炎亚种Mccp、绵羊支原体Y-98、猪鼻支原体BST-7、巴氏杆菌以及结核分枝杆菌扩增结果均为阴性。应用该方法对临床病料的检测结果与培养鉴定结果的符合率为100%,表明该方法具有良好的特异性和敏感性,可以应用于临床检测。 相似文献
10.
11.
Li Y Xin J Gao Y Zhang J Nicholas RA Lin Y 《Veterinary journal (London, England : 1997)》2009,179(1):137-141
In this study, six Chinese strains of Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) isolated between 1953-1960 were analysed and their molecular characteristics compared to those of the African PG1 and Afade strains, the European C305 and 138/5 strains and the closely related caprine M. mycoides subsp.mycoides large colony type Y-goat strain. PCR amplification of long DNA fragments showed that the six Chinese strains, the PG1 strain and the Y-goat strain, just like Afade, did not have the 8.84 kb deletion characteristic of the European strains C305 and 138/5. In comparison, the lppB gene sequence of the six MmmSC Chinese strains was found to be 99% homologous to that of PG1and Afade, but <93% homologous to the Y-goat sequence. The anti-rLppB antiserum reacted with PG1, Y-goat and the six Chinese strains at 67 kDa sites in Western blot, indicating that the lppB gene and its encoding protein exist in the Chinese strains. Multilocus sequence analysis (MLSA) of MmmSC strains from various regions confirmed that the Chinese strains were identical to the African and Australian cluster. This finding was further supported by the outcome of selective primer amplification. Based on these results, it is suggested that CBPP in China may have originated from Australia. 相似文献
12.
Lipoprotein lppC, an immunodominant antigen, and its corresponding gene lppC were characterised in Mycoplasma mycoides subspecies mycoides small colony (SC) type, the etiological agent of contagious bovine pleuropneumonia (CBPP). The lppC gene was found in the type strain of M. mycoides subsp. mycoides SC and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. Southern blot analysis indicated the presence of at least four copies of lppC in the genome of M. mycoides subsp. mycoides SC, of which only one seems to be functional. Genes homologous to lppC have also been detected in closely related mycoplasmas such as M. mycoides subsp. mycoides large colony (LC) type and in M. sp. bovine group 7. lppC is encoded as a precursor with a consensus sequence for a prokaryotic signal peptidase II. The amino acid sequence of lppC and its precursor showed similarity to both LppB (at the N-terminal domain) and LppQ (at the C-terminal domain), two lipoproteins described previously in M. mycoides subsp. mycoides SC. The N-terminal domain of the mature lppC seems to be surface exposed. The C-terminal domain presented an integral membrane structure made up of five repeated units, rich in hydrophobic and aromatic amino acids, which may have pore forming potential in the mycoplasmal membrane. A recombinant peptide representing the N-terminal half of lppC was obtained following cloning in vector pETHIS-1 and expression in Escherichia coli hosts. The recombinant protein was used on immunoblots for serological analysis of sera from cattle that were naturally or experimentally infected with M. mycoides subsp. mycoides SC. 相似文献
13.
Mycoplasma mycoides subsp. mycoides SC (MmmSC) is the etiological agent of contagious bovine pleuropneumonia (CBPP). Although eradicated in most developed countries, the disease reappeared in Europe in the 1990s. This reappearance may have been caused either by importation from sub-Saharan Africa, where CBPP is still endemic, or by the reemergence of virulent strains in Europe, as suggested by earlier studies. A multilocus sequence analysis scheme has been developed to address this issue and, most importantly, to be able to monitor new epidemics. The alignment of the full genome sequence of the reference strain PG1 and the partial genome sequence of a pathogenic strain allowed the identification of polymorphic sites. Nineteen initial loci were selected within housekeeping genes, genes of unknown function and non coding sequences. The suitability of these loci for genotyping MmmSC strains was first tested on six strains of diverse geographic origin. The analyses showed that the published PG1 sequence contained a number of specific polymorphisms that were therefore of no use for molecular typing. Among the eight informative polymorphic loci finally selected, only one (ftsY) was positioned within a housekeeping gene. Three main groups and 31 different allelic profiles were identified among 51 strains and strain variants examined. Cluster analysis confirmed that European strains from the 1990s did not originate from Africa. It also showed a genetic link between a European strain isolated in 1967 and those found in southern Africa and Australia. This was in agreement with historical data showing that CBPP was introduced in these regions during colonisation in the 19th century. 相似文献
14.
Bashiruddin JB de Santis P Persson A Ball H Regalla J 《Research in veterinary science》2005,78(3):1057-205
Cattle from Northern Portugal, many with pulmonary lesions typical of contagious bovine pleuropneumonia, were investigated for the presence of Mycoplasma mycoides subspecies mycoides small colony (MmmSC), which is the causative agent of CBPP, with several detection tests. Sandwich ELISA that included a culture enrichment stage, and 2 different PCR diagnostic systems were used to detect MmmSC in lung and mediastinal lymph node tissues from these animals. The comparison of typical CBPP pathology with the results of detection revealed that no single one of these methods provided a perfect match to the pathological data. Best performing tests were the PCR with laser induced fluorescence and PCR with pleuroTRAP kit (Chemicon, Australia), which are diagnostic systems based on amplification of genomic MmmSC DNA followed by sensitive detection of the amplified products. These were followed by the broth-enriched sandwich ELISA, which uses a monoclonal antibody specific to the M. mycoides cluster, to capture the antigen. 相似文献
15.
Contagious bovine pleuropneumonia is a bacterial disease caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC), and included in list A of the Office International des Epizooties. It is one of the major constraints to cattle raising in sub-Saharan and south-western Africa and also a threat to all countries currently free of the disease. MmmSC strains were considered very homogeneous until 1995, when various techniques such as enzymatic restriction of whole DNA or Southern blotting showed that this was not the case. These techniques are unfortunately difficult to standardize and require the extraction of DNA from an MmmSC culture. We therefore decided to investigate the possibility of constructing a molecular epidemiology tool based on multilocus sequence analysis (MLSA) with PCR amplification of various loci followed by sequencing. Six loci were found suitable for this purpose and an additional PCR was designed to detect the presence of an 8.8kb deletion described by others in some strains. Fifteen different MLSA profiles were evidenced in our study. They allowed a clear distinction between European, south-western African and sub-Saharan strains. In addition, the results obtained on strain PO1967 confirmed its European origin, even though it does not exhibit the 8.8kb deletion. This new tool for contagious bovine pleuropneumonia may prove particularly useful for identifying MmmSC strains in countries at risk from contamination. It can also easily be refined by adding more strains or other loci of interest. 相似文献
16.
We describe the development and analytical validation of a 7-plex polymerase chain reaction assay coupled to a bead-based liquid suspension array for detection of multiple ruminant Mycoplasma spp. The assay employs a combination of newly designed and previously validated primer-probe sets that target genetic loci specific for Mycoplasma bovis, Mycoplasma mycoides cluster, Mycoplasma mycoides subsp. mycoides SC (MmmSC) and Mycoplasma capricolum subspecies capripneumoniae (Mccp). Analytical sensitivity for the targeted Mycoplasma species ranged from 10 fg to 1 pg of purified gDNA extracted from broth cultures (approximately 8-800 MmmSC genome equivalents). In silico comparison of primers and probes, and analytical assessment with a range of near-neighbor Mycoplasma species and multiple bacterial respiratory pathogens demonstrated 100% analytical specificity of the assay. To assess assay performance and diagnostic specificity, 192 bovine respiratory samples were analyzed by incorporating a high throughput DNA extraction platform. The assay correctly classified all samples as negative for MmmSC or Mccp. All 33 field samples confirmed as positive for M. bovis by sequencing the uvrC gene were positive in the assay. The results from this study indicate that the bead-based liquid suspension array will provide a reliable, analytically sensitive and specific platform to simultaneously interrogate ruminant respiratory samples for multiple Mycoplasma species, including M. mycoides cluster organisms that are exotic to the United States. Sequential addition of primer-probe sets to the assay did not significantly impact analytical sensitivity of individual primer-probe combinations, suggesting that expanding the assay to include more Mycoplasma species will not compromise overall performance. 相似文献
17.
Fitzmaurice J Sewell M Manso-Silván L Thiaucourt F McDonald WL O'Keefe JS 《New Zealand veterinary journal》2008,56(1):40-47
AIM: To develop real-time PCR assays for the detection and differentiation of members of the Mycoplasma mycoides cluster. METHODS: Five real-time PCR assays were designed to allow differentiation of members of the M. mycoides cluster: an assay for detection of the M. mycoides subspecies, viz M. mycoides subsp mycoides large colony (MmmLC), M. mycoides subsp capri (Mmc), and M. mycoides subsp mycoides small colony (MmmSC); one for the detection of the M. capricolum subspecies, viz M. capricolum subsp capricolum (Mcc), M. capricolum subsp capripneumoniae (Mccp), and Mycoplasma sp bovine group 7 (BG7); and three for the specific detection of MmmSC, Mccp, and BG7. A panel of 74 Mycoplasma isolates from various geographical origins and a panel of 21 other bacterial isolates were used to evaluate the sensitivity and specificity of the assays. RESULTS: The assays displayed 100% analytical sensitivity in detecting all target Mycoplasma isolates. The analytical detection limit for the assays to detect the M. mycoides subspecies, M. capricolum subspecies, and MmmSC was determined to be 100 fg of genomic DNA, while the Mccp and BG7 assays had a detection limit of 100 fg and 10 fg of genomic DNA, respectively. The M. mycoides subspecies assay had a detection limit of 10(3) (SD 10(2)) cfu/ml milk, 10(4) (SD 10(4)) cfu per swab, and 10(3) (SD 10(3)) cfu/g lung in inoculated samples. The assays displayed 100% specificity when applied to non-target bacterial isolates and to 110 culture-negative milk samples. CONCLUSIONS: The assays were highly sensitive and specific, and provide accurate detection and differentiation of the members of the M. mycoides cluster. 相似文献
18.
Stipkovits L Dán A Varga E De Santis P Lelly R Kaszanyitzky E Paluska IF Tenk M Tekes L Harrach B 《Acta veterinaria Hungarica》2000,48(4):375-385
At abattoirs and farms, 1248 sera were collected from animals representing 121 farms, and examined by complement fixation test using Mycoplasma mycoides subspecies mycoides small colony type (MmmSC) antigen. All sera were negative except seven from four farms, giving ++ reactions in the serum dilution of 1:10. On retesting, these sera and additional 30 sera collected repeatedly in both farms gave negative results. In isolation attempts, 953 lung samples collected from slaughtered cattle at the same abattoirs, and 326 nasal swabs collected from 11 herds proved to be negative for the presence of MmmSC, but M. bovis was isolated frequently. In the small farms 23.95% of the animals had pleurisy and/or pneumonia while in the large herds 34.69% had lesions. DNA extracted from 50 nasal swabs and 430 lung samples was examined by polymerase chain reaction (PCR) using M. mycoides cluster-specific primers. DNA from further 325 lung samples was tested by the more specific M. mycoides subspecies mycoides small colony/large colony/capri specific primers and 196 samples by nested PCR specific for MmmSC. All gave negative results. The detection level of cluster-specific primers and the more specific primers was 33.4 pg of DNA, whereas that of nested PCR was 0.33 pg. 相似文献