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1.
根据折光马尔太虫的基因保守序列设计了1套特异性环介导等温扩增(LAMP)引物,建立了折光马尔太虫LAMP可视化检测方法。该方法全部反应可在1h内完成;可通过肉眼观察颜色直接判定结果;检测的灵感性可达20fg,高于常规PCR方法100倍;对其他贝类常见病原体的检测结果均为阴性。结果表明,所建立的折光马尔太虫LAMP检测方法简便、快速、灵敏、特异,可用于贝类折光马尔太虫感染的快速检测。  相似文献   

2.
Chlamydophila psittaci is the causative agent of human psittacosis and avian chlamydiosis. This zoonotic pathogen is frequently transmitted from infected birds to humans. Therefore proper and rapid detection of C. psittaci in birds is important to control this disease. We developed a method for detecting C. psittaci by using SYBR Green Real-time PCR based on targeting the cysteine-rich protein gene (envB) of C. psittaci. This one step procedure was highly sensitive and rapid for detection and quantification of C. psittaci from fecal samples. This assay was also able to detect other zoonotic Chlamydophila species such as C. abortus and C. felis. The assay is well suited for use as a routine detection method in veterinary medicine.  相似文献   

3.
根据猪链球菌2型荚膜多糖和马链球菌兽疫亚种类M蛋白的保守区序列分别设计了2对简并引物,建立了一种能同时检测猪链球菌2型和马链球菌兽疫亚种的双重PCR方法。结果显示,该双重PCR能从100个细菌的混合纯培养物中扩增出2条目的片段。而且可以直接从病料组织中检测到相应的病原菌。用建立的双重PCR方法和细菌分离培养法平行检测人工感染的组织病料,PCR方法与细菌培养法的阳性检出率基本一致,但PCR方法的特异性好、敏感性高,简便易行,可以用于猪链球菌病的流行病学调查和实验室的快速鉴别诊断。  相似文献   

4.
Loop-mediated isothermal amplification (LAMP) assay is a simple, rapid and specific detection method and has been used for detection and identification of different Campylobacter species. In this study, we develop a LAMP assay specific for detection of a particular clone (clone SA) of Campylobacter jejuni, associated with the vast majority of recent sheep abortions in the U.S. Using a set of specific primers for C. jejuni IA3902 (a clone SA isolate) and genomic DNA or boiled cell extract as template, the target DNA was amplified at 63 °C for 50 min in a water bath. A positive reaction was identified visually as white precipitate or fluorescence under UV, and confirmed by gel electrophoresis. Detection limit of the assay was comparable to that of conventional PCR. The LAMP was shown to be specific for detection of clone SA when tested on a number of C. jejuni strains of different genetic backgrounds. Applicability of the LAMP assay for specific detection of clone SA was demonstrated in animal tissues experimentally infected with IA3902 or genetically diverse C. jejuni strains. Since clone SA is the predominant cause of sheep abortions in the U.S. and is a zoonotic pathogen, the LAMP assay may be a valuable detection tool in future epidemiological studies.  相似文献   

5.
Simultaneous detection of three porcine viruses by multiplex PCR   总被引:2,自引:0,他引:2  
Specific oligonucleotide primers were selected and combined in a multiplex arrangement, in order to detect simultaneously three economically important porcine viruses by polymerase chain reaction (PCR). The pathogen panel was comprised of viruses that cause reproductive failure in infected herds: Aujeszky's disease virus (ADV), porcine parvovirus (PPV) and porcine respiratory and reproductive syndrome virus (PRRSV). In order to reduce the time required for the detection of the pathogens, the assay was optimised to a RapidCycler PCR instrument. The multiplex PCR assay was shown to be specific, sensitive and rapid, because the results were read in less than 60 min after sample preparation. Due to its speed, efficiency and sensitivity, the described rapid multiplex PCR assay serves as a useful novel tool in the veterinary diagnostic laboratories for the quick and complex detection of these important porcine pathogens.  相似文献   

6.
A direct-PCR assay was developed for the rapid detection of Taylorella equigenitalis, a Gram-negative bacterium responsible for contagious equine metritis (CEM) in Equidae. The bacteria may be detected in equine genital swabs without need for a preliminary step of DNA extraction or bacterial isolation. Specificity was determined with 125 isolates of T. equigenitalis, 24 isolates of Taylorella asinigenitalis, five commensal bacteria of the genital tract and a facultative intracellular pathogen of foals found in large concentration in soil. Our PCR is specific and amplified a 413-bp 16S ribosomal DNA product only in all T. equigenitalis.  相似文献   

7.
环介导恒温扩增(LAMP)-检测沙门氏菌   总被引:1,自引:0,他引:1  
建立一种能够快速准确地检测沙门氏菌的LAMP方法。根据沙门氏菌invA基因设计了引物,然后进行LAMP反应条件的优化、特异性试验,通过LAMP与PCR灵敏度的试验与实际样品进行检出率的比较。LAMP方法特异性好,最佳反应温度为63℃,只对沙门氏菌进行扩增;沙门氏菌的检测灵敏度为7~8cfu/mL。LAMP方法检测沙门氏菌特异性强、灵敏度高、时间短且操作简便,有望成为快速检测沙门氏菌的新方法。  相似文献   

8.
建立一种能够快速准确地检测沙门氏菌的LAMP方法。根据沙门氏菌invA基因设计了引物,然后进行LAMP反应条件的优化、特异性试验,通过LAMP与PCR灵敏度的试验与实际样品进行检出率的比较。LAMP方法特异性好,最佳反应温度为63℃,只对沙门氏菌进行扩增;沙门氏菌的检测灵敏度为7~8cfu/mL。LAMP方法检测沙门氏菌特异性强、灵敏度高、时间短且操作简便,有望成为快速检测沙门氏菌的新方法。  相似文献   

9.
Chen M  Li LP  Wang R  Liang WW  Huang Y  Li J  Lei AY  Huang WY  Gan X 《Veterinary microbiology》2012,159(3-4):526-530
Large-scale streptococcal outbreaks occurred continuously in tilapia farms of China from 2009 to 2011. The objective of this study was to characterize the prevalent strains of tilapia streptococci from the main cultured areas of China through species specific PCR and pulse field gel electrophoresis (PFGE). A total of 105 prevalent strains were isolated from Guangdong, Guangxi, Hainan and Fujian provinces between 2006 and 2011, 85 of which were identified as Streptococcus agalactiae while the rest were all identified as Streptococcus iniae. The prevalent stains in 2006 and 2007 were S. iniae (94.7%, 18/19), with S. agalactiae account for only 5.3% (1/19); The prevalent strains in 2009 and 2011 however changed to S. agalactiae (97.7%, 84/86), with only 2.3% (2/86) was S. iniae. Of these 105 strains, a total of 13 PFGE types (A-M) were characterized, among which D, F, G and K genotypes were predominant, accounting for 81.90% (86/105). The cluster analysis of PFGE electropherograms separated S. iniae and S. agalactiae to two distinctive branches, 20 strains of S. iniae exhibiting 3 types of PFGE band patterns with a similarity of 94.8-100%, and the 85 strains of S. agalactiae producing 10 types of PFGE band patterns with a similarity between 48.4% and 100%. Data suggested that the prevalent strains of tilapia streptococci in China have shifted from the former (before 2008) dominant strains of S. iniae to the current (2009-2011) dominant strains of S. agalactiae. Moreover, PFGE genotypes of the prevalent strains demonstrated geographic differences and temporal changes.  相似文献   

10.
根据猪链球菌2型的mrp基因自设计和合成了一对可扩增长度为885bp目的片段的引物,成功地建立了检测溶菌酶释放蛋白(MPR)的PCR方法,用XbaⅠ内切酶进行酶切,获得了与预期一致的578bp和307bp2的2个片段,并进行了PCR的特异性试验和敏感性试验。对马链球菌兽疫亚种、猪丹毒杆菌、猪肺疫巴氏杆菌和猪肺炎支原体的PCR检测结果均呈阴性;检测的敏感度可达100个细菌。另外,对9株从病猪体内分离的猪链球菌2型菌株进行检测了8个呈阳性;对15份正常屠宰猪扁桃体分离物的检测结果是1份为阳性。结果表明此法特异性敏感性均很高,可作为MRP快速诊和流行病学调查的手段。  相似文献   

11.
根据鸡白痢沙门菌与鸡伤寒沙门菌的rfbS基因在第237和第598位碱基的不同,设计和合成了等位基因特异性PCR引物,建立了快速检测鸡白痢沙门菌的PCR方法,并应用该方法对鸡白痢沙门菌临床分离样品进行了PCR鉴定。结果显示,该PCR方法能够特异性地鉴定鸡白痢沙门菌,检测灵敏度达100PgDNA。对35个经常规方法鉴定的鸡白痢沙门菌分离株应用等位基因特异性PCR方法进行鉴定,鉴定出33株鸡白痢沙门菌,符合率为94.3%。表明,建立的等位基因特异性PCR方法能够准确而快速地鉴定鸡白痢沙门菌。  相似文献   

12.
We developed a PCR assay for the rapid and sensitive detection of virulent Streptococcus suis type 2 and highly virulent S. suis type 1 in tonsillar specimens from pigs. The PCR primers were based on the sequence of the gene encoding the EF-protein of virulent S. suis type 2 strains (MRP+EF+) and highly virulent S. suis type 1 strains (MRP(s)EF+) and of the EF protein of weakly virulent S. suis type 2 strains (MRP+EF). The latter strains give rise to larger PCR products than the virulent strains of S. suis type 1 and 2. A positive control template was included in the assay to identify false negative results. The PCR was evaluated using tonsillar specimens from herds known (or suspected) to be infected and herds without an S. suis history. The results obtained with the PCR assay were compared with the results obtained with a newly developed bacteriological examination. In this bacteriological examination we were able to identify the EF-positive strains directly in the tonsillar specimens. From the 99 tonsils examined, 48 were positive in the PCR and 51 negative. All specimens from which EF-positive S. suis strains were isolated were also positive in the PCR assay. Three samples were positive in the PCR, but negative by bacteriological examination. The results demonstrated that the PCR is a highly specific and sensitive diagnostic tool for the detection of pigs carrying virulent strains of S. suis type 2 and highly virulent strains of type 1. Application of the assay may contribute to the control of S. suis infections.  相似文献   

13.
Streptococcus iniae is a major fish pathogen producing invasive infections that result in economic losses in aquaculture. Gentamicin protection assays were used to investigate the ability of different S. iniae strains to invade and adhere to fibroblastic-like fish cell line SAF-1. All strains tested were detected intracellularly using both techniques, with variable internalization degrees between strains. The experiments carried out at 4°C demonstrated that active cell metabolism is necessary for bacterial internalization. Intracellular bacteria were detected for up to 3 d with a round morphology and were stained with 4',6-diamidino-2-phenylindole (DAPI), indicating that some bacterial cells may remain viable inside SAF-1 cells. Our in vitro findings indicate that S. iniae is capable of adhering, entering, and surviving within fibroblastic cells, which may be important for the persistence and establishment of a carrier state.  相似文献   

14.
Streptococcus iniae is a major fish pathogen producing invasive infections that result in economic losses in aquaculture. Development of in vitro models of S. iniae virulence may provide insight to the pathogenesis of infection in vivo. Three S. iniae strains (K288, 94-426, and 29178) were tested for virulence in a hybrid-striped bass (HSB) model using intraperitoneal injection. S. iniae strains K288 and 94-426 caused high levels of mortality in HSB (lethal dose 2x10(5)CFU) while strain 29178 was avirulent even upon IP challenge with 1000-fold higher inocula. In vitro assays were developed to test for the presence of characteristics previously associated with virulence in other species of pathogenic Streptococcus in animals and humans. In vitro differences relevant to virulence were not detected for beta-hemolysin activity, sensitivity to antimicrobial peptides, or adherence and invasion of epithelial cell layers. However, in whole-blood killing assays, the pathogenic strains were resistant to blood clearance, while 29178 was cleared (P<0.001) and more sensitive to complement (P<0.001). The avirulent strain 29178 was most efficiently phagocytosed and was most susceptible to intracellular killing (P<0.01) by the carp leukocyte cell line (CLC). When exposed to reactive oxygen species, strain 29178 was most susceptible. When the oxidative burst of CLC cells was inhibited, intracellular survival of 29178 was rescued fivefold, while no significant enhancement in survival of K288 or 94-426 was detected. Our results indicate that resistance to phagocytosis, oxidative killing, and associated phagocytic clearance is a significant factor in S. iniae virulence.  相似文献   

15.
为建立一种能快速检测鸡传染性贫血病毒病(CIAV)的检测方法,根据基因库中鸡传染性贫血病毒病的保守序列,设计一套特异性环介导等温扩增(LAMP)引物,建立了CIAV的LAMP可视化检测方法。该法敏感性可迭10fg,高于常规PCR方法10倍;全部反应可在1h内完成;可通过肉眼观察颜色直接判定结果;对其它鸡常见病原体的检测结果均为阴性。结果表明建立的LAMP方法简便、快速、灵敏、特异,可用于CIAV感染的快速检测。  相似文献   

16.
为建立一种快速检测鸭Ⅰ型肝炎病毒(DHV I)的方法,本研究根据基因库中DHV Ⅰ基因的保守序列,设计特异性环介导等温扩增(LAMP)引物,建立了DHV I的RT-LAMP可视化检测方法。该方法的敏感性可达10fg,高于常规PCR方法 100倍;全部反应可在1 h内完成;可以通过肉眼观察颜色直接判定结果;对其它鸭常见病原体的检测结果均为阴性。实验结果表明建立的RT-LAMP方法简便、快速、灵敏、特异,可用于DHV Ⅰ感染的快速检测。  相似文献   

17.
A Mycoplasma iowae real-time polymerase chain reaction (PCR) assay using primers and probes targeting the 16S rRNA gene was developed and field-validated in this study. The assay specifically identified M. iowae with a detection limit of 80 colony-forming units (cfu) per turkey cloacal swab sample (3.2 cfu per PCR reaction). It was validated by testing 154 field turkey cloacal swab samples in parallel with culture isolation. The diagnostic sensitivity of the PCR was 97.6%, and the specificity was 95.5%. The real-time PCR developed in this study is a rapid, sensitive, and cost-effective alternative to culture isolation for detecting M. iowae from cloacal swab samples.  相似文献   

18.
Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious, and protection is mediated by specific anti-S. iniae antibodies. Although effective, the specific vaccine components important for efficacy are not known. In the present study, an immunoproteomic approach was utilized to identify whole-cell lysate proteins of S. iniae that stimulated specific antibody production in Nile tilapia (Oreochromis niloticus) following vaccination. Groups of tilapia were vaccinated by intraperitoneal injection with the modified S. iniae bacterin or were mock-vaccinated, and at 30 d post-vaccination sera samples were obtained from individual fish. Vaccination of tilapia with the S. iniae vaccine stimulated significantly elevated specific antibody responses against proteins of the bacterium and passive immunization of tilapia with this serum demonstrated the antibodies were highly protective. Whole-cell lysate proteins of S. iniae were separated by 2D-PAGE and were probed with a pooled serum sample from vaccinated tilapia. A total of eleven unique immunogenic proteins were positively identified by mass spectrometry. Based on research conducted on homologous proteins in other Streptococcus spp., antibodies specific for three of the identified proteins, enolase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase, are likely involved in protection from streptococcosis caused by S. iniae.  相似文献   

19.
蜡样芽孢杆菌是一种可引起食物中毒的常见食源性细菌,属于革兰氏阳性的条件致病菌,广泛存在于土壤、空气、水及植物源、动物源加工的食品中。近年发现也能感染包括人在内的多种动物,是一种人兽共患性细菌,特别是能够引起人畜肠道疾病,导致腹泻型或呕吐型食物中毒。快速准确检测蜡样芽孢杆菌是控制其污染和感染后治疗的关键环节。作者对蜡样芽孢杆菌的检测方法进行了全面详细的总结,主要包括传统检测方法、普通PCR、多重PCR(mPCR)、实时荧光定量PCR(Real-time PCR)、叠氮溴化丙锭-定量PCR(PMA-qPCR)、微滴数字PCR技术(ddPCR)、环介导等温扩增(LAMP)及酶联免疫吸附测定(ELISA)。从传统方法到新兴技术,涉及传统检测技术、分子生物学检测和免疫学检测技术,作者主要总结了各方法的原理、检测范围,并对各方法的优缺点进行了比较。这些检测方法的灵敏度、精确度、样本要求等有所不同,可根据检测需要和条件限制进行选择。将分子生物学方法和免疫学等方法有效地结合起来,多角度多层次地对样品进行检测,可全面而准确地呈现检测结果。蜡样芽孢杆菌能产生多种毒素,这些毒素决定了其致病性,所以除了检测菌体外,还可以对毒素进行检测,有助于确定病原及其致病力。总的来说,蜡样芽孢杆菌对人畜的健康安全均构成了威胁,快速准确地检测能有效辅助治疗和提前预防,作者将主要检测方法进行了总结,希望能有助于全面准确地评估蜡样芽孢杆菌的风险,为主动监测和预警提供科学依据。  相似文献   

20.
本研究旨在建立一种能够同时鉴别包括大肠杆菌O157:H7、沙门菌、空肠弯曲菌、单核细胞增生李斯特菌、霍乱弧菌、副溶血弧菌和金黄色葡萄球菌7种常见食源性致病菌的GeXP多重PCR检测方法。根据这些致病菌在GenBank上公布的保守基因序列,设计合成了7对特异性GeXP引物。用单一或混合细菌样品的DNA模板优化反应条件,设置对照组,构建重组质粒,随机组合不同浓度的样品,验证所建立的GeXP方法的特异性、敏感性和准确性。最后用该方法检测120份临床样品,进一步验证所建立的GeXP检测方法的准确性和可靠性。结果显示,单一或混合模板的GeXP检测均能特异性出现相应清晰峰值,可在103拷贝·μL-1水平上同时特异地检测出7种细菌病原体,不同浓度模板混合时,本试验所建立的方法依然可检测出对应病原体。检测120份临床样品,GeXP多重PCR阳性率为2.50%(3/120)~15.83%(19/120),普通PCR阳性率为2.50%(3/120)~15.00%(18/120),GeXP多重PCR多检出8份阳性,表明GeXP方法更为敏感与准确。本研究建立的同时鉴别7种食源性致病菌的GeXP多重PCR检测方法,具有高通量、特异性强和敏感性高的特点,为食源性常见致病菌感染或混合感染提供了快速分子诊断方法。  相似文献   

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