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Prakoso D, Zhu X, Rajeev S. Galleria mellonella infection model to evaluate pathogenic and nonpathogenic Leptospira strains. Vet Microbiol 2022; 264:109295. [PMID: 34875420 DOI: 10.1016/j.vetmic.2021.109295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 01/21/2023]
Abstract
The Galleria mellonella larvae infection model is emerging as a valuable tool for studying various characteristics of infectious agents and host-pathogen interaction. This system has been widely recognized as a high throughput, ethical, and cost-effective invertebrate infection model to study the virulence and pathogenesis of various bacterial pathogens. In this study, we compared the effect of Leptospira infection in G. mellonella larvae infected with Leptospira interrogans serovar Copenhageni (pathogenic) or Leptospira biflexa serovar Patoc (saprophytic) strains. We observed significant pathologic changes such as decreased activity, complete melanization, and lower survival rate in the G. mellonella larvae infected with a pathogenic strain L. interrogans serovar Copenhageni compared to those infected with a nonpathogenic strain L. biflexa serovar Patoc. Our study demonstrates the feasibility and the potential of using G. mellonella larvae as an alternative model to study virulence mechanisms and pathogenesis of Leptospira strains. Once optimized, the G. mellonella infection model can be a potential substitute for hamsters to explore various host and pathogen-related mechanistic events in Leptospira infection.
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Affiliation(s)
- Dhani Prakoso
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, 37996, Knoxville, TN, United States
| | - Xiaojuan Zhu
- Office of Information Technology, University of Tennessee, Knoxville, TN, United States
| | - Sreekumari Rajeev
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, 37996, Knoxville, TN, United States.
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Targeted Gene Candidates for Treatment and Early Diagnosis of Age-Related Macular Degeneration. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6620900. [PMID: 33604378 PMCID: PMC7872763 DOI: 10.1155/2021/6620900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/15/2020] [Accepted: 01/19/2021] [Indexed: 11/20/2022]
Abstract
Age-related macular degeneration (AMD) is an eye disease that impairs the sharp and central vision need for daily activities. Recent advances in molecular biology research not only lead to a better understanding of the genetics and pathophysiology of AMD but also to the development of applications based on targeted gene expressions to treat the disease. Clarification of molecular pathways that causing to development and progression in dry and wet types of AMD needs comprehensive and comparative investigations in particular precious biopsies involving peripheral blood samples from the patients. Therefore, in this investigation, dry and wet types of AMD patients and healthy individuals were aimed at investigating in regard to targeted gene candidates by using gene expression analysis for the first time. 13 most potent candidate genes involved in neurodegeneration were selected via in silico approach and investigated through gene expression analysis to suggest new targets for disease therapy. For the analyses, 30 individuals (10 dry and 10 wet types AMD patients and 10 healthy people) were involved in the study. SYBR-Green based Real-Time PCR analysis was performed on isolated peripheral blood mononuclear cells (PBMCs) to analyze differentially expressed genes related to these cases. According to the investigations, only the CRP gene was found to be upregulated for both dry and wet disease types. When the downregulated genes were analyzed, it was found that 11 genes were commonly decreased for both dry and wet types in the aspect of expression pattern. From these genes, CFH, CX3CR1, FLT1, and TIMP3 were found to have the most downregulated gene expression properties for both diseases. From these results, it might be concluded that these common upregulated and downregulated genes could be used as targets for early diagnosis and treatment for AMD.
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Monica N, Rathinasabapathi P, Ramya M. Development of real-time loop-mediated isothermal amplification (RealAmp) method for sensitive and rapid detection of pathogenic and nonpathogenicLeptospira. Lett Appl Microbiol 2019; 68:196-203. [DOI: 10.1111/lam.13108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/16/2018] [Accepted: 12/17/2018] [Indexed: 11/28/2022]
Affiliation(s)
- N.I. Monica
- Department of Genetic Engineering; School of Bioengineering; SRM Institute of Science and Technology; Kattankulathur Tamil Nadu India
| | - P. Rathinasabapathi
- Department of Genetic Engineering; School of Bioengineering; SRM Institute of Science and Technology; Kattankulathur Tamil Nadu India
| | - M. Ramya
- Department of Genetic Engineering; School of Bioengineering; SRM Institute of Science and Technology; Kattankulathur Tamil Nadu India
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Buchholz DE, Pennington BO, Croze RH, Hinman CR, Coffey PJ, Clegg DO. Rapid and efficient directed differentiation of human pluripotent stem cells into retinal pigmented epithelium. Stem Cells Transl Med 2013; 2:384-93. [PMID: 23599499 DOI: 10.5966/sctm.2012-0163] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Controlling the differentiation of human pluripotent stem cells is the goal of many laboratories, both to study normal human development and to generate cells for transplantation. One important cell type under investigation is the retinal pigmented epithelium (RPE). Age-related macular degeneration (AMD), the leading cause of blindness in the Western world, is caused by dysfunction and death of the RPE. Currently, RPE derived from human embryonic stem cells are in clinical trials for the treatment of AMD. Although protocols to generate RPE from human pluripotent stem cells have become more efficient since the first report in 2004, they are still time-consuming and relatively inefficient. We have found that the addition of defined factors at specific times leads to conversion of approximately 80% of the cells to an RPE phenotype in only 14 days. This protocol should be useful for rapidly generating RPE for transplantation as well as for studying RPE development in vitro.
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Affiliation(s)
- David E Buchholz
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, CA, USA
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Schlötelburg C, Wintzingerode C, Hauck R, Wintzingerode F, Hegemann W, Göbel UB. Microbial structure of an anaerobic bioreactor population that continuously dechlorinates 1,2-dichloropropane. FEMS Microbiol Ecol 2009; 39:229-37. [PMID: 19709202 DOI: 10.1111/j.1574-6941.2002.tb00925.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The bacterial diversity of an anaerobic 1,2-dichloropropane (DCP) dechlorinating bioreactor consortium derived from river sediment has been investigated by a combined molecular approach. By using rDNA clone libraries, denaturing gradient gel electrophoresis and quantitative real-time PCR, both Dehalococcoides ethenogenes- and Dehalobacter restrictus-like 16S rDNA sequences were found within the community. Both species are known for reductive dechlorination of tetrachloroethene. Furthermore, numerous yet-uncultured members of the Green non-sulfur bacteria occurred within the consortium. The community analyses over a period of 14 months revealed a clear population shift. D. restrictus 16S rDNA was enriched significantly and became the most abundant rDNA sequence type, suggesting that Dehalobacter spp. play a key role within the reductive dechlorination of DCP in this consortium. We propose the use of this species as an indicator to monitor the transformation process within the bioreactor.
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Affiliation(s)
- Cord Schlötelburg
- Institut für Mikrobiologie und Hygiene, Universitätsklinikum Charité, Humboldt-Universität zu Berlin, Dorotheenstr. 96, 10117 Berlin, Germany
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Anderson DH, Radeke MJ, Gallo NB, Chapin EA, Johnson PT, Curletti CR, Hancox LS, Hu J, Ebright JN, Malek G, Hauser MA, Rickman CB, Bok D, Hageman GS, Johnson LV. The pivotal role of the complement system in aging and age-related macular degeneration: hypothesis re-visited. Prog Retin Eye Res 2009; 29:95-112. [PMID: 19961953 DOI: 10.1016/j.preteyeres.2009.11.003] [Citation(s) in RCA: 565] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During the past ten years, dramatic advances have been made in unraveling the biological bases of age-related macular degeneration (AMD), the most common cause of irreversible blindness in western populations. In that timeframe, two distinct lines of evidence emerged which implicated chronic local inflammation and activation of the complement cascade in AMD pathogenesis. First, a number of complement system proteins, complement activators, and complement regulatory proteins were identified as molecular constituents of drusen, the hallmark extracellular deposits associated with early AMD. Subsequently, genetic studies revealed highly significant statistical associations between AMD and variants of several complement pathway-associated genes including: Complement factor H (CFH), complement factor H-related 1 and 3 (CFHR1 and CFHR3), complement factor B (CFB), complement component 2 (C2), and complement component 3 (C3). In this article, we revisit our original hypothesis that chronic local inflammatory and immune-mediated events at the level of Bruch's membrane play critical roles in drusen biogenesis and, by extension, in the pathobiology of AMD. Secondly, we report the results of a new screening for additional AMD-associated polymorphisms in a battery of 63 complement-related genes. Third, we identify and characterize the local complement system in the RPE-choroid complex - thus adding a new dimension of biological complexity to the role of the complement system in ocular aging and AMD. Finally, we evaluate the most salient, recent evidence that bears directly on the role of complement in AMD pathogenesis and progression. Collectively, these recent findings strongly re-affirm the importance of the complement system in AMD. They lay the groundwork for further studies that may lead to the identification of a transcriptional disease signature of AMD, and hasten the development of new therapeutic approaches that will restore the complement-modulating activity that appears to be compromised in genetically susceptible individuals.
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Affiliation(s)
- Don H Anderson
- Center for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
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Buchholz DE, Hikita ST, Rowland TJ, Friedrich AM, Hinman CR, Johnson LV, Clegg DO. Derivation of Functional Retinal Pigmented Epithelium from Induced Pluripotent Stem Cells. Stem Cells 2009; 27:2427-34. [DOI: 10.1002/stem.189] [Citation(s) in RCA: 332] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Desai C, Jain K, Patel B, Madamwar D. Efficacy of bacterial consortium-AIE2 for contemporaneous Cr(VI) and azo dye bioremediation in batch and continuous bioreactor systems, monitoring steady-state bacterial dynamics using qPCR assays. Biodegradation 2009; 20:813-26. [DOI: 10.1007/s10532-009-9269-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 05/26/2009] [Indexed: 11/25/2022]
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Radeke MJ, Peterson KE, Johnson LV, Anderson DH. Disease susceptibility of the human macula: Differential gene transcription in the retinal pigmented epithelium/choroid. Exp Eye Res 2007; 85:366-80. [PMID: 17662275 DOI: 10.1016/j.exer.2007.05.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 05/18/2007] [Accepted: 05/22/2007] [Indexed: 10/23/2022]
Abstract
The discoveries of gene variants associated with macular diseases have provided valuable insight into their molecular mechanisms, but they have not clarified why the macula is particularly vulnerable to degenerative disease. Its predisposition may be attributable to specialized structural features and/or functional properties of the underlying macular RPE/choroid. To examine the molecular basis for the macula's disease susceptibility, we compared the gene expression profile of the human RPE/choroid in the macula with the profile in the extramacular region using DNA microarrays. Seventy-five candidate genes with differences in macular:extramacular expression levels were identified by microarray analysis, of which 29 were selected for further analysis. Quantitative PCR confirmed that 21 showed statistically significant differences in expression. Five genes were expressed at higher levels in the macula. Two showed significant changes in the macular:extramacular expression ratio; another two exhibited changes in absolute expression level, as a function of age or AMD. Several of the differentially expressed genes have potential relevance to AMD pathobiology. One is an RPE cell growth factor (TFPI2), five are extracellular matrix components (DCN, MYOC, OGN, SMOC2, TFPI2), and six are related to inflammation (CCL19, CCL26, CXCL14, SLIT2) and/or angiogenesis (CXCL14, SLIT2, TFPI2, WFDC1). The identification of regional differences in gene expression in the RPE/choroid is a first step in clarifying the macula's propensity for degeneration. These findings lay the groundwork for further studies into the roles of the corresponding gene products in the normal, aged, and diseased macula.
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Affiliation(s)
- Monte J Radeke
- Center for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
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Kositanont U, Rugsasuk S, Leelaporn A, Phulsuksombati D, Tantitanawat S, Naigowit P. Detection and differentiation between pathogenic and saprophytic Leptospira spp. by multiplex polymerase chain reaction. Diagn Microbiol Infect Dis 2006; 57:117-22. [PMID: 17020799 DOI: 10.1016/j.diagmicrobio.2006.07.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 07/11/2006] [Accepted: 07/24/2006] [Indexed: 10/24/2022]
Abstract
A multiplex polymerase chain reaction (PCR) was developed for diagnosing leptospirosis and differentiating pathogenic and saprophytic leptospires. Specific primers were designed to amplify 23S rDNA from pathogenic Leptospira and saprophytic Leptospira spp. PCR products from 27 pathogenic and 5 (including 1 intermediate) saprophytic serovars were 615 and 316 base pairs (bp), respectively. After the restriction enzyme's digestion of PCR products, the fragments by SacI of pathogenic serovars and by PstI of saprophytic serovars were 339 and 276 bp and 202 and 114 bp, respectively. The PCR primers enabled amplification of DNA from L. meyeri serovar Ranarum as a pathogenic Leptospira spp. The PCR assay could detect 1 to 2 cells of leptospires and not amplify DNA from other 18 bacterial species. The sensitivity and specificity of this PCR in rat kidney, using isolation as gold standard, were 98.6% and 100%, respectively. The most appropriate sample preparation of blood for detecting DNA was buffy coat. Among the sample preparations from 7 laboratory-confirmed leptospirosis cases, leptospiral DNA was detected in all 7 buffy coat preparations, whereas leptospiral DNA was detected in only 3 plasma or serum samples. The PCR assay may be useful as a diagnostic tool for leptospirosis.
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Affiliation(s)
- Uraiwan Kositanont
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
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Jouglard SDD, Simionatto S, Seixas FK, Nassi FL, Dellagostin OA. Nested polymerase chain reaction for detection of pathogenic leptospires. Can J Microbiol 2006; 52:747-52. [PMID: 16917533 DOI: 10.1139/w06-027] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptospirosis is a widespread zoonosis caused by pathogenic members of the genus Leptospira that has a great impact on human and veterinary public health. Early diagnosis of leptospirosis is important because severe lepto spiral infection can have a fulminant course. The available serological techniques for the diagnosis of leptospirosis have low sensitivity during the early stage of the disease. Efforts are being made to develop simpler, effective, efficient, and inexpensive diagnostic methods. In this work, we first evaluate a polymerase chain reaction (PCR) based method for diagnosis of leptospirosis. Primers were designed to amplify a 264 bp region within the lipL32 gene that is conserved among pathogenic Leptospira and absent in nonpathogenic species. The sensitivity and specificity of the assay were evaluated using 7 saprophytic serovars, 37 pathogenic serovars, and 15 other microorganisms. The method was very specific for pathogenic serovars, however, it lacked sensitivity. To enhance the sensitivity, another primer pair was designed to amplify a 183 bp region within the 264 bp region of the lipL32 gene and was used in a nested PCR assay. This approach was much more sensitive than conventional PCR.Key words: leptospirosis, diagnosis, nested PCR, lipL32.
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Hageman GS, Hancox LS, Taiber AJ, Gehrs KM, Anderson DH, Johnson LV, Radeke MJ, Kavanagh D, Richards A, Atkinson J, Meri S, Bergeron J, Zernant J, Merriam J, Gold B, Allikmets R, Dean M. Extended haplotypes in the complement factor H (CFH) and CFH-related (CFHR) family of genes protect against age-related macular degeneration: Characterization, ethnic distribution and evolutionary implications. Ann Med 2006; 38:592-604. [PMID: 28950782 DOI: 10.1080/07853890601097030] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Variants in the complement factor H gene (CFH) are associated with age-related macular degeneration (AMD). CFH and five CFH-related genes (CFHR1-5) lie within the regulators of complement activation (RCA) locus on chromosome 1q32. AIMS AND METHODS In this study, the structural and evolutionary relationships between these genes and AMD was refined using a combined genetic, molecular and immunohistochemical approach. RESULTS We identify and characterize a large, common deletion that encompasses both the CFHR1 and CFHR3 genes. CFHR1, an abundant serum protein, is absent in subjects homozygous for the deletion. Genotyping analyses of AMD cases and controls from two cohorts demonstrates that deletion homozygotes comprise 1.1% of cases and 5.7% of the controls (chi-square = 32.8; P = 1.6 E-09). CFHR1 and CFHR3 transcripts are abundant in liver, but undetectable in the ocular retinal pigmented epithelium/choroid complex. AMD-associated CFH/CFHR1/CFHR3 haplotypes are widespread in human populations. CONCLUSION The absence of CFHR1 and/or CFHR3 may account for the protective effects conferred by some CFH haplotypes. Moreover, the high frequencies of the 402H allele and the delCFHR1/CFHR3 alleles in African populations suggest an ancient origin for these alleles. The considerable diversity accumulated at this locus may be due to selection, which is consistent with an important role for the CFHR genes in innate immunity.
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Affiliation(s)
- Gregory S Hageman
- a Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa.,b Center for the Study of Macular Degeneration, University of California, Santa Barbara, CA
| | - Lisa S Hancox
- a Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa
| | - Andrew J Taiber
- a Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa
| | - Karen M Gehrs
- a Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa
| | - Don H Anderson
- b Center for the Study of Macular Degeneration, University of California, Santa Barbara, CA.,c Neuroscience Research Institute, University of California, Santa Barbara, CA
| | - Lincoln V Johnson
- b Center for the Study of Macular Degeneration, University of California, Santa Barbara, CA.,c Neuroscience Research Institute, University of California, Santa Barbara, CA
| | - Monte J Radeke
- b Center for the Study of Macular Degeneration, University of California, Santa Barbara, CA.,c Neuroscience Research Institute, University of California, Santa Barbara, CA
| | - David Kavanagh
- d Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St Louis, MO
| | - Anna Richards
- d Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St Louis, MO
| | - John Atkinson
- d Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St Louis, MO
| | - Seppo Meri
- e Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | | | - Jana Zernant
- h Department of Ophthalmology, Columbia University, New York
| | - Joanna Merriam
- h Department of Ophthalmology, Columbia University, New York
| | - Bert Gold
- g Laboratory of Genomic Diversity, National Cancer Institute, NCI-Frederick, Frederick, Maryland
| | - Rando Allikmets
- h Department of Ophthalmology, Columbia University, New York.,i Department of Pathology and Cell Biology, Columbia University, New York
| | - Michael Dean
- g Laboratory of Genomic Diversity, National Cancer Institute, NCI-Frederick, Frederick, Maryland
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Abu-Halaweh M, Bates J, Patel BKC. Rapid detection and differentiation of pathogenic Campylobacter jejuni and Campylobacter coli by real-time PCR. Res Microbiol 2005; 156:107-14. [PMID: 15636755 DOI: 10.1016/j.resmic.2004.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Accepted: 08/17/2004] [Indexed: 10/26/2022]
Abstract
A two-tube real-time assay, developed in a LightCycler, was used to detect, identify and differentiate Campylobacter jejuni and Campylobacter coli from all other pathogenic members of the family Campylobacteriaceae. In the first assay, continuous monitoring of the fluorescence resonance energy transfer (FRET) signal acquired from the hybridisation of two adjacent fluoroprobes, a specific FITC probe 5'-GTGCTAGCTTGCTAGAACTTAGAGA-FITC-3') and a universal downstream probe Cy5 (5'-Cy5-AGGTGITGCATGGITGTCGTTGTCG-PO(4)-3'), to the 681-base pair 16S rRNA gene amplicon target (Escherichia coli position 1024-1048 and 1050-1075, respectively) produced by the primer pair, F2 (ATCTAATGGCTTAACCATTAAAC, E. coli position 783) and Cam-Rev (AATACTAAACTAGTTACCGTC, E. coli position 1464), detected C. coli, C. lari and C. jejuni. As expected, a Tm of 65 degrees C was derived from the temperature-dependent probe DNA strand disassociation. In the second assay, an increase in fluorescence due to binding of the intercalating dye SYBR Green I to the DNA amplicons of the hippuricase gene (hipO) (produced by the primer pair hip2214F and hip2474R) was observed for C. jejuni but not for C. coli which lacks the hipO gene. A Tm of 85+/-0.5 and 56 degrees C determined from temperature-dependent dye-DNA disassociation identified C. jejuni and the non-specific PCR products, respectively, in line with our expectation. The two-tube assay was subsequently used to identify and differentiate the 169 Campylobacteriaceae isolates of animal, human, plant and bird origin held in our culture collection into C. coli (74 isolates), C. jejuni (86 isolates) and non-C. coli-C. jejuni (9 isolates). In addition, the method successfully detected C. jejuni, C. coli and C. lari from 24-h enrichment cultures initiated from 30 commercial chicken samples.
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Affiliation(s)
- Marwan Abu-Halaweh
- Microbial Gene Research and Resources Facility, Eskitis Institute and School of Biomolecular and Biomedical Sciences, Griffith University, Nathan, Brisbane 4111, Australia
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Ooteman MC, Vago AR, Koury MC. Potential application of low-stringency single specific primer-PCR in the identification ofLeptospirain the serum of patients with suspected leptospirosis. Can J Microbiol 2004; 50:1073-9. [PMID: 15714239 DOI: 10.1139/w04-096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study we tested the potential use of low-stringency single specific primer-PCR (LSSP-PCR) for genetically typing Leptospira directly from biological samples. Serum samples obtained from 29 patients with clinically suspected leptospirosis were amplified by specific PCR, using the previously selected G1 and G2 primers. The PCR products of approximately 300 bp were subsequently used as a template for LSSP-PCR analysis. We were able to produce genetic signatures from the leptospires present in the human samples, which permitted us to make a preliminary identification of the infective serovar by comparing the LSSP-PCR profiles obtained directly from serum samples with those from reference leptospires. Thus, LSSP-PCR has the potential to become a useful diagnostic tool for identifying leptospires in biological samples without the need for bacteria isolation and culture.Key words: LSSP-PCR, Leptospira.
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Affiliation(s)
- Márcia Costa Ooteman
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Fenk R, Haas R, Kronenwett R. Molecular monitoring of minimal residual disease in patients with multiple myeloma. ACTA ACUST UNITED AC 2004; 9:17-33. [PMID: 14965865 DOI: 10.1080/10245330310001638965] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Improvement of transplantation strategies and a multitude of emerging novel therapies result in a better treatment outcome in patients with multiple myeloma (MM). This gives rise to the need for sensitive methods to detect minimal residual disease (MRD) in MM. Qualitative molecular monitoring using allele-specific oligonucleotide PCR for the immunoglobulin heavy chain (IgH) is well established to detect clonotypic cells after therapy or in stem cell harvests. Recently, real-time IgH PCR or limiting dilution based PCR assays offer the possibility to quantify the amount of residual tumour cells. In this review, different qualitative and quantitative IgH PCR techniques will be discussed as well as the current clinical role of molecular monitoring of MRD in patients with MM.
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Affiliation(s)
- Roland Fenk
- Department of Haematology, Oncology and Clinical Immunology, University of Duesseldorf, Germany.
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Nicolas L, Prina E, Lang T, Milon G. Real-time PCR for detection and quantitation of leishmania in mouse tissues. J Clin Microbiol 2002; 40:1666-9. [PMID: 11980939 PMCID: PMC130941 DOI: 10.1128/jcm.40.5.1666-1669.2002] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leishmania spp. are intracellular protozoan parasites that cause a wide spectrum of diseases in humans and dogs worldwide. However, monitoring of the Leishmania burden in its different hosts is still based on cumbersome and poorly sensitive methods. Here we have developed a highly accurate real-time PCR assay with which to reproducibly detect and quantify the relative Leishmania major burden in mouse tissue samples. The assay is performed with the LightCycler system using SYBR Green I and primers amplifying a ca. 120-bp fragment from minicircles of the kinetoplast DNA (kDNA). The assay was able to detect as little as 100 fg of L. major DNA per reaction, which is equivalent to 0.1 parasite. The standard curve designed for quantitation of parasites showed linearity over an at least 6-log DNA concentration range, corresponding to 0.1 to 10(4) parasites per reaction, with a correlation coefficient of 0.979. The assay also proved to have a detection range of the same magnitude as that used for detection of L. donovani and L. amazonensis, but it was 100-fold less sensitive for L. mexicana. When applied to tissues from experimentally infected mice, the real-time PCR assay is not only as sensitive as a conventional PCR assay for detection of Leishmania kDNA but also more rapid. Results indicate that this assay is compatible with the clinical diagnosis of leishmaniasis and will be a great help to scientists who use animals to monitor the efficacy of antileishmanial drugs or vaccines or decipher the unique properties of the life cycle of Leishmania spp.
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Affiliation(s)
- Luc Nicolas
- Unité d'Immunophysiologie et Parasitisme Intracellulaire, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris Cedex 15, France.
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Azek F, Grossiord C, Joannes M, Limoges B, Brossier P. Hybridization assay at a disposable electrochemical biosensor for the attomole detection of amplified human cytomegalovirus DNA. Anal Biochem 2000; 284:107-13. [PMID: 10933863 DOI: 10.1006/abio.2000.4692] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A disposable electrochemical biosensor for the detection of DNA sequences related to the human cytomegalovirus (HCMV) is described. The sensor relies on the adsorption of an amplified human cytomegalovirus DNA strand onto the sensing surface of a screen-printed carbon electrode, and to its hybridization to a complementary single-stranded biotinylated DNA probe. The extent of hybrids formed was determined with streptavidin conjugated to horseradish peroxidase. The peroxidase label was indirectly quantified by measuring the amount of the chromophore and electroactive product 2,2'-diaminoazobenzene generated from the o-phenylenediamine substrate. The intensity of differential pulse voltammetric peak currents resulting from the reduction of the enzyme-generated product was related to the number of target HCMV-amplified DNA molecules present in the sample, and the results were compared to those obtained with standard methods, i.e., agarose gel electrophoresis quantification and colorimetric hybridization assay in a microtiter plate. A detection limit of 0.6 amol/ml of HCMV-amplified DNA fragment was obtained with the electrochemical DNA biosensor. The electrochemical method was 23,000-fold more sensitive than the gel electrophoresis technique and 83-fold more sensitive than the colorimetric hybridization assay in a microtiter plate.
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Affiliation(s)
- F Azek
- Laboratoire de Microbiologie Médicale et Moléculaire, Faculté de Médecine et Pharmacie, 7 Boulevard Jeanned'Arc, Dijon, 21033, France
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de Silva D, Wittwer CT. Monitoring hybridization during polymerase chain reaction. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 741:3-13. [PMID: 10839126 DOI: 10.1016/s0378-4347(00)00055-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The polymerase chain reaction (PCR) is usually analyzed by gel electrophoresis for size separation of PCR products. Additional separation techniques, such as single-stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE) and denaturing high-performance liquid chromatography (DHPLC), can also be used to scan for sequence alterations. These techniques are all based on the effect of PCR product hybridization on mobility. Hybridization can also be monitored with fluorescence during PCR without chromatographic or electrophoretic separation. Continuous monitoring of PCR allows the detection, quantification and sequence specificity of PCR products to be assessed, often without any need for further analysis. In such a closed system, PCR quantification with sensitivity to the single copy level can be achieved using either double-stranded DNA binding dyes or fluorescently labeled allele-specific oligonucleotide (ASO) probes. Melting curve analysis with ASO probes can be used to genotype various alleles, including single base alterations. The integration of rapid cycle PCR and ASO probes in an automated system greatly facilitates research and clinical applications of nucleic acid analysis in genetics, oncology, and infectious disease.
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Affiliation(s)
- D de Silva
- Idaho Technology Inc., Salt Lake City, UT 84108, USA
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