51
|
Abstract
Platforms for pathogen discovery have improved since the days of Koch and Pasteur; nonetheless, the challenges of proving causation are at least as daunting as they were in the late 1800 s. Although we will almost certainly continue to accumulate low-hanging fruit, where simple relationships will be found between the presence of a cultivatable agent and a disease, these successes will be increasingly infrequent. The future of the field rests instead in our ability to follow footprints of infectious agents that cannot be characterized using classical microbiological techniques and to develop the laboratory and computational infrastructure required to dissect complex host-microbe interactions. I have tried to refine the criteria used by Koch and successors to prove linkage to disease. These refinements are working constructs that will continue to evolve in light of new technologies, new models, and new insights. What will endure is the excitement of the chase. Happy hunting!
Collapse
|
52
|
Black CE, Costerton JW. Current concepts regarding the effect of wound microbial ecology and biofilms on wound healing. Surg Clin North Am 2010; 90:1147-60. [PMID: 21074033 DOI: 10.1016/j.suc.2010.08.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Biofilms are a collection of microbes that adhere to surfaces by manufacturing a matrix that shields them from environmental elements. Wound biofilms are difficult to evaluate clinically, and standard culture methods are inadequate for capturing the true bioburden present in the biofilm. New molecular techniques provide the means for rapid detection and evaluation of wound biofilms, and may prove to be useful in the clinical setting. Studies have shown that many commercial topical agents and wound dressings in use are ineffective against the biofilm matrix. At this stage, mechanical debridement appears to be essential in the eradication of a wound biofilm. Topical antimicrobial agents and antibiotics may be effective in the treatment of the wound bed after debridement in the prevention of biofilm reformation.
Collapse
Affiliation(s)
- Carrie E Black
- Department of General Surgery, General Surgery Residency Program, Marshfield Clinic, 1000 North Oak Avenue, Marshfield, WI 54449, USA
| | | |
Collapse
|
53
|
Molecular diagnosis of bloodstream infections: planning to (physically) reach the bedside. Curr Opin Infect Dis 2010; 23:311-9. [PMID: 20592531 DOI: 10.1097/qco.0b013e32833bfc44] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE OF REVIEW Faster identification of infecting microorganisms and treatment options is a first-ranking priority in the infectious disease area, in order to prevent inappropriate treatment and overuse of broad-spectrum antibiotics. Standard bacterial identification is intrinsically time-consuming, and very recently there has been a burst in the number of commercially available nonphenotype-based techniques and in the documentation of a possible clinical impact of these techniques. RECENT FINDINGS Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is now a standard diagnostic procedure on cultures and hold promises on spiked blood. Meanwhile, commercial PCR-based techniques have improved with the use of bacterial DNA enrichment methods, the diversity of amplicon analysis techniques (melting curve analysis, microarrays, gel electrophoresis, sequencing and analysis by mass spectrometry) leading to the ability to challenge bacterial culture as the gold standard for providing earlier diagnosis with a better 'clinical' sensitivity and additional prognostic information. SUMMARY Laboratory practice has already changed with MALDI-TOF MS, but a change in clinical practice, driven by emergent nucleic acid-based techniques, will need the demonstration of real-life applicability as well as robust clinical-impact-oriented studies.
Collapse
|
54
|
Deyde VM, Sampath R, Garten RJ, Blair PJ, Myers CA, Massire C, Matthews H, Svoboda P, Reed MS, Pohl J, Klimov AI, Gubareva LV. Genomic signature-based identification of influenza A viruses using RT-PCR/electro-spray ionization mass spectrometry (ESI-MS) technology. PLoS One 2010; 5:e13293. [PMID: 20967258 PMCID: PMC2953491 DOI: 10.1371/journal.pone.0013293] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 09/16/2010] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The emergence and rapid spread of the 2009 H1N1 pandemic influenza A virus (H1N1pdm) in humans highlights the importance of enhancing the capability of existing influenza surveillance systems with tools for rapid identification of emerging and re-emerging viruses. One of the new approaches is the RT-PCR electrospray ionization mass spectrometry (RT-PCR/ESI-MS) technology, which is based on analysis of base composition (BC) of RT-PCR amplicons from influenza "core" genes. Combination of the BC signatures represents a "genomic print" of an influenza A virus. METHODOLOGY/PRINCIPAL FINDINGS Here, 757 samples collected between 2006 and 2009 were tested, including 302 seasonal H1N1, 171 H3N2, 7 swine triple reassortants, and 277 H1N1pdm viruses. Of the 277 H1N1pdm samples, 209 were clinical specimens (throat, nasal and nasopharyngeal swabs, nasal washes, blood and sputum). BC signatures for the clinical specimen from one of the first cases of the 2009 pandemic, A/California/04/2009, confirmed it as an unusual, previously unrecognized influenza A virus, with "core" genes related to viruses of avian, human and swine origins. Subsequent analysis of additional 276 H1N1pdm samples revealed that they shared the genomic print of A/California/04/2009, which differed from those of North American swine triple reassortant viruses, seasonal H1N1 and H3N2 and other viruses tested. Moreover, this assay allowed distinction between "core" genes of co-circulating groups of seasonal H1N1, such as clades 2B, 2C, and their reassortants with dual antiviral resistance to adamantanes and oseltamivir. CONCLUSIONS/SIGNIFICANCE The RT-PCR/ESI-MS assay is a broad range influenza identification tool that can be used directly on clinical specimens for rapid and accurate detection of influenza virus genes. The assay differentiates the H1N1pdm from seasonal and other nonhuman hosts viruses. Although not a diagnostic tool, this assay demonstrates its usefulness and robustness in influenza virus surveillance and detection of novel and unusual viruses with previously unseen genomic prints.
Collapse
Affiliation(s)
- Varough M. Deyde
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Rangarajan Sampath
- Genomics & Computational Biology, Ibis Biosciences, Carlsbad, California, United States of America
| | - Rebecca J. Garten
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Patrick J. Blair
- Naval Respiratory Disease Laboratory, Naval Health Research Center, San Diego, California, United States of America
| | - Christopher A. Myers
- Naval Respiratory Disease Laboratory, Naval Health Research Center, San Diego, California, United States of America
| | - Christian Massire
- Genomics & Computational Biology, Ibis Biosciences, Carlsbad, California, United States of America
| | - Heather Matthews
- Genomics & Computational Biology, Ibis Biosciences, Carlsbad, California, United States of America
| | - Pavel Svoboda
- Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Matthew S. Reed
- Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Jan Pohl
- Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Alexander I. Klimov
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Larisa V. Gubareva
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| |
Collapse
|
55
|
Initial identification and characterization of an emerging zoonotic influenza virus prior to pandemic spread. J Clin Microbiol 2010; 48:4228-34. [PMID: 20861338 DOI: 10.1128/jcm.01336-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two cases of febrile respiratory illness associated with untypeable influenza A virus were identified in Southern California in March 2009. One was initially detected as influenza virus using an experimental diagnostic device in a clinical trial, while the other was detected at a local reference lab using a diagnostic PCR assay. In both cases, analyses yielded negative results for strain-specific tests targeting circulating strains of influenza A virus (seasonal H1 and H3). These two samples became the first reported cases of the pandemic 2009/H1N1 influenza virus. The first reportable characterization was made from the second collected specimen on 15 April 2009 at the Centers for Disease Control and Prevention central lab using traditional culture and sequencing methods. The novel nature of the strain and its apparent zoonotic origins were initially characterized using the first collected specimen at the Naval Health Research Center in San Diego, CA, on 13 April using an experimental molecular analysis tool, PCR electro-spray ionization-mass spectrometry (PCR/ESI-MS), designed to amplify PCR products from any strain of influenza virus and to generate informative (phylogenetic) strain identifications through mass spectrometry of PCR amplicons. The ability of this high-throughput tool to correctly identify both well-characterized and novel influenza strains offers the possibility to integrate surveillance for emerging strains with on-site rapid diagnosis used for patient management, shortening the times between the emergence of new strains, their detection and identification, and appropriate public health response activities. Here we describe the initial characterization of the pandemic 2009/H1N1 influenza strain and discuss the possible roles of diagnostic tools with discovery potential.
Collapse
|
56
|
Jabbour RE, Wade MM, Deshpande SV, Stanford MF, Wick CH, Zulich AW, Snyder AP. Identification of Yersinia pestis and Escherichia coli Strains by Whole Cell and Outer Membrane Protein Extracts with Mass Spectrometry-Based Proteomics. J Proteome Res 2010; 9:3647-55. [DOI: 10.1021/pr100402y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Rabih E. Jabbour
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - Mary Margaret Wade
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - Samir V. Deshpande
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - Michael F. Stanford
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - Charles H. Wick
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - Alan W. Zulich
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| | - A. Peter Snyder
- SAIC, Aberdeen Proving Ground, Maryland 21010, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010-5424, and Science and Technology Corporation, Edgewood, Maryland 21040
| |
Collapse
|
57
|
Response to Questions Posed by the Food Safety and Inspection Service Regarding Determination of the Most Appropriate Technologies for the Food Safety and Inspection Service To Adopt in Performing Routine and Baseline Microbiological Analyses†,‡. J Food Prot 2010; 73:1160-200. [DOI: 10.4315/0362-028x-73.6.1160] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
58
|
Grant-Klein RJ, Baldwin CD, Turell MJ, Rossi CA, Li F, Lovari R, Crowder CD, Matthews HE, Rounds MA, Eshoo MW, Blyn LB, Ecker DJ, Sampath R, Whitehouse CA. Rapid identification of vector-borne flaviviruses by mass spectrometry. Mol Cell Probes 2010; 24:219-28. [PMID: 20412852 DOI: 10.1016/j.mcp.2010.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/02/2010] [Accepted: 04/05/2010] [Indexed: 11/30/2022]
Abstract
Flaviviruses are a highly diverse group of RNA viruses classified within the genus Flavivirus, family Flaviviridae. Most flaviviruses are arthropod-borne, requiring a mosquito or tick vector. Several flaviviruses are highly pathogenic to humans; however, their high genetic diversity and immunological relatedness makes them extremely challenging to diagnose. In this study, we developed and evaluated a broad-range Flavivirus assay designed to detect both tick- and mosquito-borne flaviviruses by using RT-PCR/electrospray ionization mass spectrometry (RT-PCR/ESI-MS) on the Ibis T5000 platform. The assay was evaluated with a panel of 13 different flaviviruses. All samples were correctly identified to the species level. To determine the limit of detection for the mosquito-borne primer sets, serial dilutions of RNA from West Nile virus (WNV) were assayed and could be detected down to an equivalent viral titer of 0.2 plaque-forming units/mL. Analysis of flaviviruses in their natural biological background included testing Aedes aegypti mosquitoes that were laboratory-infected with dengue-1 virus. The assay accurately identified the virus within infected mosquitoes, and we determined the average viral genome per mosquito to be 2.0 x 10(6). Using human blood, serum, and urine spiked with WNV and mouse blood and brain tissues from Karshi virus-infected mice, we showed that these clinical matrices did not inhibit the detection of these viruses. Finally, we used the assay to test field-collected Ixodes scapularis ticks collected from sites in New York and Connecticut. We found 16/322 (5% infection rate) ticks positive for deer tick virus, a subtype of Powassan virus. In summary, we developed a single high-throughput Flavivirus assay that could detect multiple tick- and mosquito-borne flaviviruses and thus provides a new analytical tool for their medical diagnosis and epidemiological surveillance.
Collapse
Affiliation(s)
- Rebecca J Grant-Klein
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
59
|
Identification of pathogenic Vibrio species by multilocus PCR-electrospray ionization mass spectrometry and its application to aquatic environments of the former soviet republic of Georgia. Appl Environ Microbiol 2010; 76:1996-2001. [PMID: 20118359 DOI: 10.1128/aem.01919-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Ibis T5000 is a novel diagnostic platform that couples PCR and mass spectrometry. In this study, we developed an assay that can identify all known pathogenic Vibrio species and field-tested it using natural water samples from both freshwater lakes and the Georgian coastal zone of the Black Sea. Of the 278 total water samples screened, 9 different Vibrio species were detected, 114 (41%) samples were positive for V. cholerae, and 5 (0.8%) samples were positive for the cholera toxin A gene (ctxA). All ctxA-positive samples were from two freshwater lakes, and no ctxA-positive samples from any of the Black Sea sites were detected.
Collapse
|
60
|
Fabris D. A role for the MS analysis of nucleic acids in the post-genomics age. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:1-13. [PMID: 19897384 DOI: 10.1016/j.jasms.2009.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Revised: 09/04/2009] [Accepted: 09/04/2009] [Indexed: 05/28/2023]
Abstract
The advances of mass spectrometry in the analysis of nucleic acids have tracked very closely the exciting developments of instrumentation and ancillary technologies, which have taken place over the years. However, their diffusion in the broader life sciences community has been and will be linked to the ever evolving focus of biomedical research and its changing demands. Before the completion of the Human Genome Project, great emphasis was placed on sequencing technologies that could help accomplish this project of exceptional scale. After the publication of the human genome, the emphasis switched toward techniques dedicated to the exploration of sequences not coding for actual protein products, which amount to the vast majority of transcribed elements. The broad range of capabilities offered by mass spectrometry is rapidly advancing this platform to the forefront of the technologies employed for the structure-function investigation of these noncoding elements. Increasing focus on the characterization of functional assemblies and their specific interactions has prompted a re-evaluation of what has been traditionally construed as nucleic acid analysis by mass spectrometry. Inspired by the accelerating expansion of the broader field of nucleic acid research, new applications to fundamental biological studies and drug discovery will help redefine the evolving role of MS-analysis of nucleic acids in the post-genomics age.
Collapse
Affiliation(s)
- Daniele Fabris
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, Maryland 21228, USA.
| |
Collapse
|
61
|
Oberacher H. Frontiers of mass spectrometry in nucleic acids analysis. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2010; 16:351-365. [PMID: 20530841 DOI: 10.1255/ejms.1045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Nucleic acids research is a highly competitive field of research. A number of well established methods are available. The current output of high throughput ("next generation") sequencing technologies is impressive, and still technologies are continuing to make progress regarding read lengths, bp per second, accuracy and costs. Although in the 1990s MS was considered as an analytical platform for sequencing, it was soon realized that MS will never be competitive. Thus, the focus shifted from de novo sequencing towards other areas of application where MS has proven to be a powerful analytical tool. Potential niches for the application of MS in nucleic acids research include genotyping of genetic markers (single nucleotide polymorphisms, short tandem repeats, and combinations thereof), quality control of synthetic oligonucleotides, metabolic profiling of therapeutics, characterization of modified nucleobases in DNA and RNA molecules, and the study of non covalent interactions among nucleic acids as well as interactions of nucleic acids with drugs and proteins. The diversity of possible applications for MS highlights its significance for nucleic acid research.
Collapse
Affiliation(s)
- Herbert Oberacher
- Institute of Legal Medicine, Innsbruck Medical University, Innsbruck, Austria.
| |
Collapse
|
62
|
Mandviwala T, Shinde R, Kalra A, Sobel JD, Akins RA. High-throughput identification and quantification of Candida species using high resolution derivative melt analysis of panfungal amplicons. J Mol Diagn 2009; 12:91-101. [PMID: 20007848 DOI: 10.2353/jmoldx.2010.090085] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungal infections pose unique challenges to molecular diagnostics; fungal molecular diagnostics consequently lags behind bacterial and viral counterparts. Nevertheless, fungal infections are often life-threatening, and early detection and identification of species is crucial to successful intervention. A high throughput PCR-based method is needed that is independent of culture, is sensitive to the level of one fungal cell per milliliter of blood or other tissue types, and is capable of detecting species and resistance mutations. We introduce the use of high resolution melt analysis, in combination with more sensitive, inclusive, and appropriately positioned panfungal primers, to address these needs. PCR-based amplification of the variable internal transcribed regions of the rDNA genes generates an amplicon whose sequence melts with a shape that is characteristic and therefore diagnostic of the species. Simple analysis of the differences between test and reference melt curves generates a single number that calls the species. Early indications suggest that high resolution melt analysis can distinguish all eight major species of Candida of clinical significance without interference from excess human DNA. Candida species, including mixed and novel species, can be identified directly in vaginal samples. This tool can potentially detect, count, and identify fungi in hundreds of samples per day without further manipulation, costs, or delays, offering a major step forward in fungal molecular diagnostics.
Collapse
Affiliation(s)
- Tasneem Mandviwala
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | | | | | | | | |
Collapse
|
63
|
Detection and identification of Ehrlichia species in blood by use of PCR and electrospray ionization mass spectrometry. J Clin Microbiol 2009; 48:472-8. [PMID: 19955274 DOI: 10.1128/jcm.01669-09] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rapid detection and identification of Ehrlichia species improves clinical outcome for patients suspected of ehrlichiosis. We describe an assay that employs multilocus PCR and electrospray ionization mass spectrometry (PCR/ESI-MS) to detect and identify Ehrlichia species directly from blood specimens. The results were compared to those of a colorimetric microtiter PCR enzyme immunoassay (PCR-EIA) used as a diagnostic assay. Among 213 whole-blood samples collected from patients who were clinically suspected of ehrlichiosis from 1 May to 1 August 2008 at Vanderbilt University Hospital, 40 were positive for an Ehrlichia species by PCR/ESI-MS, giving a positive rate of 18.8%. In comparison to the PCR-EIA, PCR/ESI-MS possessed a sensitivity, a specificity, and positive and negative predictive values of 95.0%, 98.8%, 95.0%, and 98.8%, respectively. The 38 specimens that were positive for Ehrlichia by both PCR/ESI-MS and the PCR-EIA were further characterized to the species level, with 100% agreement between the two assays. In addition, Rickettsia rickettsii was detected by PCR/ESI-MS from four specimens that were confirmed retrospectively by serology and PCR-EIA. In three specimens, the PCR/ESI-MS assay identified Pseudomonas aeruginosa, Neisseria meningitidis, and Staphylococcus aureus; these were confirmed by culture and/or clinical diagnosis as being clinically relevant. From specimen processing to result reporting, the PCR/ESI-MS assay can be completed within 6 h, providing another laboratory tool for the diagnosis of ehrlichiosis. Moreover, this system may provide rapid detection and identification of additional pathogens directly from blood specimens.
Collapse
|
64
|
Abstract
The rate of discovery of new microbes and of new associations of microbes with health and disease is accelerating. Many factors contribute to this phenomenon including those that favor the true emergence of new pathogens as well as new technologies and paradigms that enable their detection and characterization. This chapter reviews recent progress in the field of pathogen surveillance and discovery with a focus on viral hemorrhagic fevers.
Collapse
Affiliation(s)
- W Ian Lipkin
- Center for Infection and Immunity, Mailman School of Public Health of Columbia University, New York, New York, USA.
| | | | | |
Collapse
|
65
|
Belák S, Thorén P, LeBlanc N, Viljoen G. Advances in viral disease diagnostic and molecular epidemiological technologies. Expert Rev Mol Diagn 2009; 9:367-81. [PMID: 19435457 PMCID: PMC7105750 DOI: 10.1586/erm.09.19] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The early and rapid detection and characterization of specific nucleic acids of medico-veterinary pathogens have proven invaluable for diagnostic purposes. The integration of amplification and signal detection systems, including online real-time devices, have increased speed and sensitivity and greatly facilitated the quantification of target nucleic acids. They have also allowed for sequence characterization using melting or hybridization curves. The newer-generation molecular diagnostic technologies offer, hitherto, unparalleled detection and discrimination methodologies, which are vital for the positive detection and identification of pathogenic agents, as well as the effects of the pathogens on the production of antibodies. The development phase of the novel technologies entails a thorough understanding of accurate diagnosis and discrimination of present and emerging diseases. The development of novel technologies can only be successful if they are transferred and used in the field with a sustainable quality-assured application to allow for the optimal detection and effective control of diseases. The aim of these new tools is to detect the presence of a pathogen agent before the onset of disease. This manuscript focuses mainly on the experiences of two World Organisation for Animal Health collaborating centers in context to molecular diagnosis and molecular epidemiology of transboundary and endemic animal diseases of viral origin, food safety and zoonoses.
Collapse
Affiliation(s)
- Sándor Belák
- Department of Virology, Joint Research and Development Division, Swedish University of Agricultural Sciences and National Veterinary Institute, Uppsala, Sweden.
| | | | | | | |
Collapse
|
66
|
Extracting evidence from forensic DNA analyses: future molecular biology directions. Biotechniques 2009; 46:339-40, 342-50. [PMID: 19480629 DOI: 10.2144/000113136] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Molecular biology tools have enhanced the capability of the forensic scientist to characterize biological evidence to the point where it is feasible to analyze minute samples and achieve high levels of individualization. Even with the forensic DNA field's maturity, there still are a number of areas where improvements can be made. These include: enabling the typing of samples of limited quantity and quality; using genetic information and novel markers to provide investigative leads; enhancing automation with robotics, different chemistries, and better software tools; employing alternate platforms for typing DNA samples; developing integrated microfluidic/microfabrication devices to process DNA samples with higher throughput, faster turnaround times, lower risk of contamination, reduced labor, and less consumption of evidentiary samples; and exploiting high-throughput sequencing, particularly for attribution in microbial forensics cases. Knowledge gaps and new directions have been identified where molecular biology will likely guide the field of forensics. This review aims to provide a roadmap to guide those interested in contributing to the further development of forensic genetics.
Collapse
|
67
|
Gardner SN, Hiddessen AL, Williams PL, Hara C, Wagner MC, Colston BW. Multiplex primer prediction software for divergent targets. Nucleic Acids Res 2009; 37:6291-304. [PMID: 19759213 PMCID: PMC2770652 DOI: 10.1093/nar/gkp659] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We describe a Multiplex Primer Prediction (MPP) algorithm to build multiplex compatible primer sets to amplify all members of large, diverse and unalignable sets of target sequences. The MPP algorithm is scalable to larger target sets than other available software, and it does not require a multiple sequence alignment. We applied it to questions in viral detection, and demonstrated that there are no universally conserved priming sequences among viruses and that it could require an unfeasibly large number of primers (∼3700 18-mers or ∼2000 10-mers) to generate amplicons from all sequenced viruses. We then designed primer sets separately for each viral family, and for several diverse species such as foot-and-mouth disease virus (FMDV), hemagglutinin (HA) and neuraminidase (NA) segments of influenza A virus, Norwalk virus, and HIV-1. We empirically demonstrated the application of the software with a multiplex set of 16 short (10 nt) primers designed to amplify the Poxviridae family to produce a specific amplicon from vaccinia virus.
Collapse
Affiliation(s)
- Shea N Gardner
- Computations/Global Security, Lawrence Livermore National Laboratory and QuantaLife, Inc, Livermore, CA, USA.
| | | | | | | | | | | |
Collapse
|
68
|
Eshoo MW, Whitehouse CA, Nalca A, Zoll S, Ecker JA, Hall TA, Pennella TTD, Duncan DD, Desai A, Moradi EK, Rudnick K, Libby B, Ranken R, Sampath R, Hofstadler SA, Ecker DJ, Blyn LB. Rapid and high-throughput pan-Orthopoxvirus detection and identification using PCR and mass spectrometry. PLoS One 2009; 4:e6342. [PMID: 19623263 PMCID: PMC2710004 DOI: 10.1371/journal.pone.0006342] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 06/01/2009] [Indexed: 11/18/2022] Open
Abstract
The genus Orthopoxvirus contains several species of related viruses, including the causative agent of smallpox (Variola virus). In addition to smallpox, several other members of the genus are capable of causing human infection, including monkeypox, cowpox, and other zoonotic rodent-borne poxviruses. Therefore, a single assay that can accurately identify all orthopoxviruses could provide a valuable tool for rapid broad orthopovirus identification. We have developed a pan-Orthopoxvirus assay for identification of all members of the genus based on four PCR reactions targeting Orthopoxvirus DNA and RNA helicase and polymerase genes. The amplicons are detected using electrospray ionization-mass spectrometry (PCR/ESI-MS) on the Ibis T5000 system. We demonstrate that the assay can detect and identify a diverse collection of orthopoxviruses, provide sub-species information and characterize viruses from the blood of rabbitpox infected rabbits. The assay is sensitive at the stochastic limit of PCR and detected virus in blood containing approximately six plaque-forming units per milliliter from a rabbitpox virus-infected rabbit.
Collapse
|
69
|
Schwahn AB, Wong JWH, Downard KM. Subtyping of the Influenza Virus by High Resolution Mass Spectrometry. Anal Chem 2009; 81:3500-6. [DOI: 10.1021/ac900026f] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander B. Schwahn
- School of Molecular & Microbial Biosciences, University of Sydney, NSW 2006, Australia, and UNSW Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Jason W. H. Wong
- School of Molecular & Microbial Biosciences, University of Sydney, NSW 2006, Australia, and UNSW Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Kevin M. Downard
- School of Molecular & Microbial Biosciences, University of Sydney, NSW 2006, Australia, and UNSW Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
70
|
Abstract
PURPOSE OF REVIEW The purpose of this article is to review the molecular methods commonly used in medical microbiology as well as to update the clinician as to newer molecular technologies that show promise in the identification of microorganisms as well as evaluation of the presence of virulence factors and antibiotic resistance determinants. RECENT FINDINGS Numerous molecular assays have been developed recently using a variety of technologies. Direct hybridization techniques have allowed analysis of blood culture bottles for organisms such as methicillin-resistant Staphylococcus aureus. Target amplification methods allow postamplification analysis using a variety of technologies depending on the clinical needs for the assay. Postamplification analysis includes methods such as Sanger sequencing, pyrosequencing, reverse hybridization, and Luminex analysis, which are becoming more widely utilized. In the future, whole genome sequencing, mass spectrometry, and microarray analysis may provide a wealth of information that can be used to specifically tailor the treatment of infectious diseases. SUMMARY The implications of current trends in molecular infectious diseases are moving towards high-throughput, simple, array-type technologies that will provide a wealth of data regarding types of organisms present in a sample and the virulence factors/resistance determinants that influence the severity of disease. As a result of these developments, infectious diseases will be more accurately and effectively treated.
Collapse
|
71
|
Downard KM, Morrissey B, Schwahn AB. Mass spectrometry analysis of the influenza virus. MASS SPECTROMETRY REVIEWS 2009; 28:35-49. [PMID: 18785239 DOI: 10.1002/mas.20194] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The role of mass spectrometry to probe characteristics of the influenza virus, and vaccine and antiviral drugs that target the virus, are reviewed. Genetic and proteomic approaches have been applied which incorporate high resolution mass spectrometry and mass mapping to genotype the virus and establish its evolution in terms of the primary structure of the surface protein antigens. A mass spectrometric immunoassay has been developed and applied to assess the structure and antigenicity of the virus in terms of the hemagglutinin antigen. The quantitation of the hemagglutinin antigen in vaccine preparations has also been conducted that is of importance to their efficacy. Finally, the characterization and quantitation of antiviral drugs against the virus, and their metabolites, have been monitored in blood, serum, and urine. The combined approaches demonstrate the strengths of modern mass spectrometric methods for the characterization of this killer virus. [This article was published online 10 September 2008. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 7 November 2008.]
Collapse
Affiliation(s)
- Kevin M Downard
- School of Molecular & Microbial Biosciences, The University of Sydney, Sydney, NSW, Australia.
| | | | | |
Collapse
|
72
|
Naffakh N, Tomoiu A, Rameix-Welti MA, van der Werf S. Host restriction of avian influenza viruses at the level of the ribonucleoproteins. Annu Rev Microbiol 2008; 62:403-24. [PMID: 18785841 DOI: 10.1146/annurev.micro.62.081307.162746] [Citation(s) in RCA: 169] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although transmission of avian influenza viruses to mammals, particularly humans, has been repeatedly documented, adaptation and sustained transmission in the new host is a rare event that in the case of humans may result in pandemics. Host restriction involves multiple genetic determinants. Among the known determinants of host range, key determinants have been identified on the genes coding for the nucleoprotein and polymerase proteins that, together with the viral RNA segments, form the ribonucleoproteins (RNPs). The RNP genes form host-specific lineages and harbor host-associated genetic signatures. The functional significance of these determinants has been studied by reassortment and reverse genetics experiments, underlining the influence of the global genetic context. In some instances the molecular mechanisms have been approached, pointing to the importance of the polymerase activity and interaction with cellular host factors. Better knowledge of determinants of host restriction will allow monitoring of the pandemic potential of avian influenza viruses.
Collapse
Affiliation(s)
- Nadia Naffakh
- Unité de Génétique Moléculaire des Virus Respiratoires, URA CNRS 3015, Institut Pasteur, Paris, 75015 France
| | | | | | | |
Collapse
|
73
|
Emerson D, Agulto L, Liu H, Liu L. Identifying and Characterizing Bacteria in an Era of Genomics and Proteomics. Bioscience 2008. [DOI: 10.1641/b581006] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
74
|
Demirev PA, Fenselau C. Mass spectrometry in biodefense. JOURNAL OF MASS SPECTROMETRY : JMS 2008; 43:1441-57. [PMID: 18720458 DOI: 10.1002/jms.1474] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Potential agents for biological attacks include both microorganisms and toxins. In mass spectrometry (MS), rapid identification of potential bioagents is achieved by detecting the masses of unique biomarkers, correlated to each agent. Currently, proteins are the most reliable biomarkers for detection and characterization of both microorganisms and toxins, and MS-based proteomics is particularly well suited for biodefense applications. Confident identification of an organism can be achieved by top-down proteomics following identification of individual protein biomarkers from their tandem mass spectra. In bottom-up proteomics, rapid digestion of intact protein biomarkers is again followed by MS/MS to provide unambiguous bioagent identification and characterization. Bioinformatics obviates the need for culturing and rigorous control of experimental variables to create and use MS fingerprint libraries for various classes of bioweapons. For specific applications, MS methods, instruments and algorithms have also been developed for identification based on biomarkers other than proteins and peptides.
Collapse
Affiliation(s)
- Plamen A Demirev
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA.
| | | |
Collapse
|
75
|
Abstract
OBJECTIVE Influenza is a major concern for intensivists in all communities in the U.S. While there is considerable concern whether or not the country will be ready for a pandemic influenza, even seasonal influenza poses a major challenge to hospitals. The objective of this review is to summarize current knowledge of influenza with emphasis on the issues that intensivist will encounter. SETTING Intensive care unit in a 450-bed, tertiary care, teaching hospital. METHODS Source data were obtained from a PubMed search of the medical literature. PubMed "related articles" search strategies were likewise employed frequently. SUMMARY AND CONCLUSIONS Seasonal influenza causes more than 200,000 hospitalizations and 41,000 deaths in the U.S. every year, and is the seventh leading cause of death in the U.S. Despite this impact there is a shortcoming in knowledge of influenza among many health care workers, and a paucity of clinical data and studies to guide therapy. Intensivists need to recognize the importance of seasonal influenza as a cause of severe morbidity and mortality. This review summarizes current knowledge of the diagnosis, complications, therapy, and infection control measures associated with influenza.
Collapse
Affiliation(s)
- John H Beigel
- National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, MD, USA.
| |
Collapse
|
76
|
Abstract
PURPOSE OF REVIEW To provide an update on the state of biofilm research in otolaryngology. RECENT FINDINGS Chronic rhinosinusitis is a polymicrobial infection, which includes planktonic and biofilm infections with bacterial and fungal elements. The importance of genetic shift in microbes, when converting into a biofilm state, as well as the multiple phenotypes in each bacterial colony cannot be overemphasized. This creates a very sophisticated community of pathogens, some of which will likely survive a simple chemical treatment. Sinus cultures cannot be expected to provide a complete knowledge of the cause of chronic sinusitis. A new diagnostic method and innovative treatment plans will be necessary to provide a lasting treatment of chronic rhinosinusitis. Surgery combined with postoperative treatment is the most effective mean of controlling the majority of chronic rhinosinusitis infections. The challenges associated with the treatment of chronic rhinosinusitis patients may be met by focusing more on the community of microorganism present in the sinuses. SUMMARY The understanding of the implication of chronic biofilm infections is growing rapidly but will require an enormous effort to completely control chronic rhinosinusitis.
Collapse
|
77
|
Juste RA, Elguezabal N, Garrido JM, Pavon A, Geijo MV, Sevilla I, Cabriada JL, Tejada A, García-Campos F, Casado R, Ochotorena I, Izeta A, Greenstein RJ. On the prevalence of M. avium subspecies paratuberculosis DNA in the blood of healthy individuals and patients with inflammatory bowel disease. PLoS One 2008; 3:e2537. [PMID: 18596984 PMCID: PMC2434204 DOI: 10.1371/journal.pone.0002537] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 05/21/2008] [Indexed: 12/13/2022] Open
Abstract
Background Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics. Methods We studied 100 healthy individuals (90 blood donors) and 246 patients with IBD. IS900 MAP DNA was identified using a nested primer PCR in the buffy coat of blood. Positive signal was confirmed as MAP by DNA sequence analysis. PCR positive results frequencies were compared according to medications used. Significance was accepted at p<0.05. Results 47% (47/100) healthy controls and 16% (40/246) IBD patients were IS900 positive (p<0.0001). MAP DNA was identified in 17% of 143 patients receiving mesalamine and 6% of 16 receiving sulfasalazine. None of the IBD patients receiving methotrexate (n = 9), 6-MP (n = 3), ciprofloxacin (n = 5) or Tacrolimus® (n = 3) had MAP DNA detectable in their blood. Discussion We found a disquietingly large percentage of healthy individuals have MAP DNA in their blood, the significance of which remains to be determined. Counter-intuitively, the incidence of MAP DNA was significantly lower in patients with IBD. Agents with the most potent in vitro antiMAP activity were associated with clearance of blood MAP DNA. We posit that the use antiMAP antibiotics was responsible for the decreased prevalence of MAP DNA in patients with IBD.
Collapse
Affiliation(s)
- Ramon A Juste
- Departamento de Producción y Sanidad Animal, Instituto Vasco de Investigación y Desarrollo Agrario (NEIKER-Tecnalia), Derio, Bizkaia, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
78
|
Rapid differentiation of influenza A virus subtypes and genetic screening for virus variants by high-resolution melting analysis. J Clin Microbiol 2008; 46:1090-7. [PMID: 18174299 DOI: 10.1128/jcm.02015-07] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We assessed the use of high-resolution melting (HRM) analysis for the rapid identification of influenza A virus subtypes and the detection of newly emerging virus variants. The viral matrix gene was amplified by LightCycler real-time reverse transcription-PCR (RT-PCR) in the presence of the LCGreen I fluorescent dye. Upon optimization of the assay conditions, all the major influenza A virus subtypes, including H1N1, H3N2, H5N1, H7N3, and H9N2, were amplifiable by this method and had a PCR product length of 179 bp. Real-time RT-PCR of in vitro-transcribed H3N2 RNA revealed a standard curve for quantification with a linear range (correlation coefficient = 0.9935) across at least 8 log units of RNA concentrations and a detection limit of 10(3) copies of viral RNA. We performed HRM analysis of the PCR products with the HR-1 instrument and used the melting profiles as molecular fingerprints for virus subtyping. The virus subtypes were identified from the high-resolution derivative plot obtained by heteroduplex formation between the PCR products of the viral isolates tested and those of the reference viral isolates. The melting profiles were consistent with minimal interassay variability. Hence, an HRM database and a working protocol were established for the identification of these five influenza A virus subtypes. When this protocol was used to test 21 clinical influenza A virus isolates, the results were comparable to those obtained by RT-PCR with hemagglutinin-specific primer sets. Sequence variants of the clinical isolates (n = 4) were also revealed by our HRM analytical scheme. This assay requires no multiplexing or hybridization probes and provides a new approach for influenza A virus subtyping and genetic screening of virus variants in a clinical virology laboratory.
Collapse
|
79
|
Sampath R, Russell KL, Massire C, Eshoo MW, Harpin V, Blyn LB, Melton R, Ivy C, Pennella T, Li F, Levene H, Hall TA, Libby B, Fan N, Walcott DJ, Ranken R, Pear M, Schink A, Gutierrez J, Drader J, Moore D, Metzgar D, Addington L, Rothman R, Gaydos CA, Yang S, St George K, Fuschino ME, Dean AB, Stallknecht DE, Goekjian G, Yingst S, Monteville M, Saad MD, Whitehouse CA, Baldwin C, Rudnick KH, Hofstadler SA, Lemon SM, Ecker DJ. Global surveillance of emerging Influenza virus genotypes by mass spectrometry. PLoS One 2007; 2:e489. [PMID: 17534439 PMCID: PMC1876795 DOI: 10.1371/journal.pone.0000489] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Accepted: 05/14/2007] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Effective influenza surveillance requires new methods capable of rapid and inexpensive genomic analysis of evolving viral species for pandemic preparedness, to understand the evolution of circulating viral species, and for vaccine strain selection. We have developed one such approach based on previously described broad-range reverse transcription PCR/electrospray ionization mass spectrometry (RT-PCR/ESI-MS) technology. METHODS AND PRINCIPAL FINDINGS Analysis of base compositions of RT-PCR amplicons from influenza core gene segments (PB1, PB2, PA, M, NS, NP) are used to provide sub-species identification and infer influenza virus H and N subtypes. Using this approach, we detected and correctly identified 92 mammalian and avian influenza isolates, representing 30 different H and N types, including 29 avian H5N1 isolates. Further, direct analysis of 656 human clinical respiratory specimens collected over a seven-year period (1999-2006) showed correct identification of the viral species and subtypes with >97% sensitivity and specificity. Base composition derived clusters inferred from this analysis showed 100% concordance to previously established clades. Ongoing surveillance of samples from the recent influenza virus seasons (2005-2006) showed evidence for emergence and establishment of new genotypes of circulating H3N2 strains worldwide. Mixed viral quasispecies were found in approximately 1% of these recent samples providing a view into viral evolution. CONCLUSION/SIGNIFICANCE Thus, rapid RT-PCR/ESI-MS analysis can be used to simultaneously identify all species of influenza viruses with clade-level resolution, identify mixed viral populations and monitor global spread and emergence of novel viral genotypes. This high-throughput method promises to become an integral component of influenza surveillance.
Collapse
Affiliation(s)
- Rangarajan Sampath
- Ibis Biosciences Inc., A Wholly Owned Subsidiary of Isis Pharmaceuticals, Carlsbad, California, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|