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Senécal J, Smyth E, Del Corpo O, Hsu JM, Amar-Zifkin A, Bergeron A, Cheng MP, Butler-Laporte G, McDonald EG, Lee TC. Non-invasive diagnosis of Pneumocystis jirovecii pneumonia: a systematic review and meta-analysis. Clin Microbiol Infect 2021; 28:23-30. [PMID: 34464734 DOI: 10.1016/j.cmi.2021.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/05/2021] [Accepted: 08/20/2021] [Indexed: 02/01/2023]
Abstract
BACKGROUND Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection commonly affecting immunocompromised people. Diagnosis usually requires invasive techniques to obtain respiratory specimens. Minimally invasive detection tests have been proposed, but their operating characteristics are poorly described. OBJECTIVES To systematically review and meta-analyse the performance of minimally invasive PCP detection tests to inform diagnostic algorithms. DATA SOURCES Medline, Embase, Cochrane Library (inception to 15 October 2020). STUDY ELIGIBILITY CRITERIA Studies of minimally invasive PCP detection tests were included if they contained a minimum of ten PCP cases. PARTICIPANTS Adults at risk of PCP. TESTS Non-invasive PCP detection tests. REFERENCE STANDARD Diagnosis using the combination of clinical and radiographical features with invasive sampling. ASSESSMENT OF RISK BIAS Using the QUADAS-2 tool. METHODS We used bivariate and, when necessary, univariate analysis models to estimate diagnostic test sensitivity and specificity. RESULTS Fifty-two studies were included; most studies (40) comprised exclusively human immunodeficiency virus (HIV) -infected individuals; nine were mixed (HIV and non-HIV), two were non-HIV and one study did not report HIV status. Sampling sites included induced sputum, nasopharyngeal aspirate, oral wash and blood. The four testing modalities evaluated were cytological staining, fluorescent antibody, PCR and lactate dehydrogenase. Induced sputum had the most data available; this modality was both highly sensitive at 99% (95% CI 51%-100%) and specific at 96% (95% CI 88%-99%). Induced sputum cytological staining had moderate sensitivity at 50% (95% CI 39%-61%) and high specificity at 100% (95% CI 100%-100%), as did fluorescent antibody testing with sensitivity 74% (95% CI 62%-87%) and specificity 100% (95% CI 91%-100%). CONCLUSION There are several promising minimally invasive PCP diagnostic tests available, some of which may reduce the need for invasive respiratory sampling. Understanding the operating characteristics of these tests can augment current diagnostic strategies and help establish a more confident clinical diagnosis of PCP. Further studies in non-HIV infected populations are needed.
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Affiliation(s)
- Julien Senécal
- Faculty of Medicine, McGill University, Montreal, Canada
| | - Elizabeth Smyth
- Research Institute of the McGill University Health Centre, Montreal, Canada
| | | | - Jimmy M Hsu
- Faculty of Medicine, McGill University, Montreal, Canada
| | | | - Amy Bergeron
- McGill University Health Centre (MUHC) Medical Libraries, Montreal, Canada
| | - Matthew P Cheng
- Research Institute of the McGill University Health Centre, Montreal, Canada; Division of Infectious Diseases, Department of Medicine, McGill University, Montreal, Canada; Division of Medical Microbiology Department of Laboratory Medicine, MUCH, Montreal, Canada
| | - Guillaume Butler-Laporte
- Division of Infectious Diseases, Department of Medicine, McGill University, Montreal, Canada; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Emily G McDonald
- Research Institute of the McGill University Health Centre, Montreal, Canada; Division of General Internal Medicine, Department of Medicine, McGill University, Montreal, Canada; Clinical Practice Assessment Unit, Department of Medicine, McGill University, Montreal, Canada
| | - Todd C Lee
- Research Institute of the McGill University Health Centre, Montreal, Canada; Division of Infectious Diseases, Department of Medicine, McGill University, Montreal, Canada; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada; Division of General Internal Medicine, Department of Medicine, McGill University, Montreal, Canada.
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Abstract
PURPOSE OF REVIEW Pneumocystis pneumonia (PCP) is a frequent opportunistic infection associated with a high mortality rate. PCP is of increasing importance in non-HIV immunocompromised patients, who present with severe respiratory distress with low fungal loads. Molecular detection of Pneumocystis in broncho-alveolar lavage (BAL) has become an important diagnostic tool, but quantitative PCR (qPCR) needs standardization. RECENT FINDINGS Despite a high negative predictive value, the positive predictive value of qPCR is moderate, as it also detects colonized patients. Attempts are made to set a cut-off value of qPCR to discriminate between PCP and colonization, or to use noninvasive samples or combined strategies to increase specificity. SUMMARY It is easy to set a qPCR cut-off for HIV-infected patients. In non-HIV IC patients, a gain in specificity could be obtained by combining strategies, that is, qPCR on BAL and a noninvasive sample, or qPCR and serum beta-1,3-D-glucan dosage.
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Wang D, Hu Y, Li T, Rong HM, Tong ZH. Diagnosis of Pneumocystis jirovecii pneumonia with serum cell-free DNA in non-HIV-infected immunocompromised patients. Oncotarget 2017; 8:71946-71953. [PMID: 29069759 PMCID: PMC5641102 DOI: 10.18632/oncotarget.18037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/08/2017] [Indexed: 01/06/2023] Open
Abstract
Conventional respiratory tract specimens, such as bronchoalveolar lavage (BAL) fluid and induced sputum for diagnosing Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients are difficult to obtain. Besides, bronchoscopy is an invasive procedure that carries the risk of causing rapidly progressive respiratory insufficiency. By contrast, serum cell-free DNA (cfDNA) is easy to obtain and has been proven useful in diagnosing cancer, pregnancy associated complications, parasite infection and sepsis. In this study, we performed quantitative polymerase chain reaction (qPCR) to assess the diagnostic efficiency of using serum cfDNA, BAL fluid, and sputum DNA for PCP. Seventy-one patients (35 PCP patients and 36 non-PCP patients) were enrolled according to the clinical PCP diagnostic criteria. The sensitivity, specificity, positive predictive value, and negative predictive value of PCR using serum cfDNA were 68.6% (95% CI, 50.7–83.1), 97.2% (95% CI, 85.5–99.9), 96.0%, and 76.1%, respectively. PCR using BAL fluid and sputum had a high sensitivity (97.1% and 91.4%, respectively) but relatively low specificity (86.1% and 86.1%, respectively). The combination of the sputum PCR OR serum cfDNA PCR yielded a sensitivity of 97.1%.These results indicated that serum cfDNA might be a valuable method in PCP diagnosis.
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Affiliation(s)
- Dong Wang
- Department of Respiratory Medicine and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Yang Hu
- Department of Respiratory Medicine and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Ting Li
- Department of Respiratory Medicine and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Heng-Mo Rong
- Department of Respiratory Medicine and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Zhao-Hui Tong
- Department of Respiratory Medicine and Critical Care Medicine, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
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Development and evaluation of a real-time PCR assay for detection of Pneumocystis jirovecii on the fully automated BD MAX platform. J Clin Microbiol 2013; 51:2337-43. [PMID: 23678059 DOI: 10.1128/jcm.00616-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Pneumocystis jirovecii is an opportunistic pathogen in immunocompromised and AIDS patients. Detection by quantitative PCR is faster and more sensitive than microscopic diagnosis yet requires specific infrastructure. We adapted a real-time PCR amplifying the major surface glycoprotein (MSG) target from Pneumocystis jirovecii for use on the new BD MAX platform. The assay allowed fully automated DNA extraction and multiplex real-time PCR. The BD MAX assay was evaluated against manual DNA extraction and conventional real-time PCR. The BD MAX was used in the research mode running a multiplex PCR (MSG, internal control, and sample process control). The assay had a detection limit of 10 copies of an MSG-encoding plasmid per PCR that equated to 500 copies/ml in respiratory specimens. We observed accurate quantification of MSG targets over a 7- to 8-log range. Prealiquoting and sealing of the complete PCR reagents in conical tubes allowed easy and convenient handling of the BD MAX PCR. In a retrospective analysis of 54 positive samples, the BD MAX assay showed good quantitative correlation with the reference PCR method (R(2) = 0.82). Cross-contamination was not observed. Prospectively, 278 respiratory samples were analyzed by both molecular assays. The positivity rate overall was 18.3%. The BD MAX assay identified 46 positive samples, compared to 40 by the reference PCR. The BD MAX assay required liquefaction of highly viscous samples with dithiothreitol as the only manual step, thus offering advantages for timely availability of molecular-based detection assays.
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5
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Samuel CM, Whitelaw A, Corcoran C, Morrow B, Hsiao NY, Zampoli M, Zar HJ. Improved detection of Pneumocystis jirovecii in upper and lower respiratory tract specimens from children with suspected pneumocystis pneumonia using real-time PCR: a prospective study. BMC Infect Dis 2011; 11:329. [PMID: 22123076 PMCID: PMC3254081 DOI: 10.1186/1471-2334-11-329] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 11/28/2011] [Indexed: 12/02/2022] Open
Abstract
Background Pneumocystis pneumonia (PCP) is a major cause of hospitalization and mortality in HIV-infected African children. Microbiologic diagnosis relies predominantly on silver or immunofluorescent staining of a lower respiratory tract (LRT) specimens which are difficult to obtain in children. Diagnosis on upper respiratory tract (URT) specimens using PCR has been reported useful in adults, but data in children are limited. The main objectives of the study was (1) to compare the diagnostic yield of PCR with immunofluorescence (IF) and (2) to investigate the usefulness of upper compared to lower respiratory tract samples for diagnosing PCP in children. Methods Children hospitalised at an academic hospital with suspected PCP were prospectively enrolled. An upper respiratory sample (nasopharyngeal aspirate, NPA) and a lower respiratory sample (induced sputum, IS or bronchoalveolar lavage, BAL) were submitted for real-time PCR and direct IF for the detection of Pneumocystis jirovecii. A control group of children with viral lower respiratory tract infections were investigated with PCR for PCP. Results 202 children (median age 3.3 [inter-quartile range, IQR 2.2 - 4.6] months) were enrolled. The overall detection rate by PCR was higher than by IF [180/349 (52%) vs. 26/349 (7%) respectively; p < 0.0001]. PCR detected more infections compared to IF in lower respiratory tract samples [93/166 (56%) vs. 22/166 (13%); p < 0.0001] and in NPAs [87/183 (48%) vs. 4/183 (2%); p < 0.0001]. Detection rates by PCR on upper (87/183; 48%) compared with lower respiratory tract samples (93/166; 56%) were similar (OR, 0.71; 95% CI, 0.46 - 1.11). Only 2/30 (6.6%) controls were PCR positive. Conclusion Real-time PCR is more sensitive than IF for the detection of P. jirovecii in children with PCP. NPA samples may be used for diagnostic purposes when PCR is utilised. Wider implementation of PCR on NPA samples is warranted for diagnosing PCP in children.
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Affiliation(s)
- Catherine M Samuel
- Division of Medical Microbiology, University of Cape Town and National Health Laboratory Service, Cape Town, South Africa.
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FUJISAWA T, SUDA T, MATSUDA H, INUI N, NAKAMURA Y, SATO J, TOYOSHIMA M, NAKANO Y, YASUDA K, GEMMA H, HAYAKAWA H, CHIDA K. Real-time PCR is more specific than conventional PCR for induced sputum diagnosis of Pneumocystispneumonia in immunocompromised patients without HIV infection. Respirology 2009; 14:203-9. [DOI: 10.1111/j.1440-1843.2008.01457.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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8
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Robberts FJL, Liebowitz LD, Chalkley LJ. Polymerase chain reaction detection of Pneumocystis jiroveci: evaluation of 9 assays. Diagn Microbiol Infect Dis 2007; 58:385-92. [PMID: 17689766 DOI: 10.1016/j.diagmicrobio.2007.02.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 02/26/2007] [Accepted: 02/27/2007] [Indexed: 11/26/2022]
Abstract
Various polymerase chain reaction (PCR) amplification strategies have been described for detecting Pneumocystis jiroveci in clinical specimens. Different combinations of primer/target and platforms have been reported to yield varying PCR detection rates. PCR was evaluated on clinical specimens using internal transcribed spacer regions of the rRNA nested, dihydropteroate synthase single and nested, dihydrofolate reductase nested, major surface glycoprotein heminested, mitochondrial large subunit rRNA (mtLSUrRNA) single and nested, 18S rRNA 1-tube nested, and real-time 5S rRNA PCR. The most sensitive PCR was subsequently compared with routine diagnostic immunofluorescence (IF) microscopy. Discrepant PCR and IF results were resolved after review of clinical and histology/cytology records. Major discrepancies were observed among the methods investigated. mtLSUrRNA nested PCR was the most sensitive, produced less false-negative results, and displayed the highest degree of concordance with histology. Direct comparison of mtLSUrRNA nested PCR versus IF yielded low sensitivity and specificity, which were improved for PCR and lowered for IF on review of clinical and laboratory records.
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MESH Headings
- DNA, Fungal/genetics
- DNA, Mitochondrial/genetics
- DNA, Ribosomal/genetics
- DNA, Ribosomal Spacer/genetics
- Dihydropteroate Synthase/genetics
- False Negative Reactions
- Fungal Proteins/genetics
- Humans
- Membrane Glycoproteins/genetics
- Microscopy, Fluorescence
- Pneumocystis Infections/diagnosis
- Pneumocystis Infections/microbiology
- Pneumocystis Infections/pathology
- Pneumocystis carinii/genetics
- Pneumocystis carinii/isolation & purification
- Polymerase Chain Reaction/methods
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5S/genetics
- Sensitivity and Specificity
- Tetrahydrofolate Dehydrogenase/genetics
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Affiliation(s)
- Frans J L Robberts
- Department of Medical Microbiology, The University of Stellenbosch, Tygerberg, South Africa.
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9
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Deepak SA, Kottapalli KR, Rakwal R, Oros G, Rangappa KS, Iwahashi H, Masuo Y, Agrawal GK. Real-Time PCR: Revolutionizing Detection and Expression Analysis of Genes. Curr Genomics 2007; 8:234-51. [PMID: 18645596 PMCID: PMC2430684 DOI: 10.2174/138920207781386960] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 02/27/2007] [Accepted: 03/02/2007] [Indexed: 02/06/2023] Open
Abstract
Invention of polymerase chain reaction (PCR) technology by Kary Mullis in 1984 gave birth to real-time PCR. Real-time PCR - detection and expression analysis of gene(s) in real-time - has revolutionized the 21(st) century biological science due to its tremendous application in quantitative genotyping, genetic variation of inter and intra organisms, early diagnosis of disease, forensic, to name a few. We comprehensively review various aspects of real-time PCR, including technological refinement and application in all scientific fields ranging from medical to environmental issues, and to plant.
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Affiliation(s)
- SA Deepak
- Department of Studies in Applied Botany and Biotechnology, University of Mysore, Manasagangotri, Mysore 570006,
India
| | - KR Kottapalli
- Plant Genome Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba 305-
8602, Ibaraki, Japan
| | - R Rakwal
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
- Research Laboratory for
Agricultural Biotechnology and Biochemistry (RLABB), GPO Box 8207, Kathmandu, Nepal
| | - G Oros
- Plant Protection Institute,
Hungarian Academy of Sciences, Budapest, Hungary
| | - KS Rangappa
- Department of Studies in Chemistry, University of Mysore,
Manasagangotri, Mysore 570006, India
| | - H Iwahashi
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
| | - Y Masuo
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
| | - GK Agrawal
- Research Laboratory for
Agricultural Biotechnology and Biochemistry (RLABB), GPO Box 8207, Kathmandu, Nepal
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Alvarez-Martínez MJ, Miró JM, Valls ME, Moreno A, Rivas PV, Solé M, Benito N, Domingo P, Muñoz C, Rivera E, Zar HJ, Wissmann G, Diehl ARS, Prolla JC, de Anta MTJ, Gatell JM, Wilson PE, Meshnick SR. Sensitivity and specificity of nested and real-time PCR for the detection of Pneumocystis jiroveci in clinical specimens. Diagn Microbiol Infect Dis 2006; 56:153-60. [PMID: 16678378 DOI: 10.1016/j.diagmicrobio.2006.03.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2005] [Revised: 02/23/2006] [Accepted: 03/08/2006] [Indexed: 02/08/2023]
Abstract
A polymerase chain reaction (PCR)-based test for Pneumocystis jiroveci (formerly Pneumocystis carinii f. sp. hominis) might be an alternative to histologic diagnoses of P. jiroveci pneumonia (PCP). However, previously developed nested PCR methods tend to have low specificities (high false-positive rates). In this study, nested and quantitative real-time PCR methods for the amplification of the P. jiroveci DHPS (dihydropteroate synthase) gene were evaluated in a variety of stored clinical samples from Spain, South Africa, and Brazil. The sensitivities of both assays were high, ranging from 62.5% to 100% depending on the type of specimen. In a subset of 71 microscopically confirmed PCP cases and 70 negative cases, the sensitivities and specificities were 94% and 81% for nested PCR and 94% and 96% for real-time PCR, respectively. Real-time PCR has a statistically significantly better specificity than nested PCR (P = .015) and is likely to generate fewer false positives.
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Klingspor L, Jalal S. Molecular detection and identification of Candida and Aspergillus spp. from clinical samples using real-time PCR. Clin Microbiol Infect 2006; 12:745-53. [PMID: 16842569 DOI: 10.1111/j.1469-0691.2006.01498.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This report describes the development of a real-time LightCycler assay for the detection and identification of Candida and Aspergillus spp., using the MagNa Pure LC Instrument for automated extraction of fungal DNA. The assay takes 5-6 h to perform. The oligonucleotide primers and probes used for species identification were derived from the DNA sequences of the 18S rRNA genes of various fungal pathogens. All samples were screened for Aspergillus and Candida to the genus level in the real-time PCR assay. If a sample was Candida-positive, typing to species level was performed using five species-specific probes. The assay detected and identified most of the clinically relevant Aspergillus and Candida spp. with a sensitivity of 2 CFU/mL blood. Amplification was 100% specific for all Aspergillus and Candida spp. tested. To assess clinical applicability, 1,650 consecutive samples (1,330 blood samples, 295 samples from other body fluids and 25 biopsy samples) from patients with suspected invasive fungal infections were analysed. In total, 114 (6.9%) samples were PCR-positive, 5.3% for Candida and 1.7% for Aspergillus spp. In patients with positive PCR results for Candida and Aspergillus, verification with conventional methods was possible in 83% and 50% of cases, respectively. In conclusion, the real-time PCR assay allows sensitive and specific detection and identification of fungal pathogens in vitro and in vivo.
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Affiliation(s)
- L Klingspor
- Department of Laboratory Medicine, Division of Clinical Bacteriology, Karolinska Institute, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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12
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Arcenas RC, Uhl JR, Buckwalter SP, Limper AH, Crino D, Roberts GD, Wengenack NL. A real-time polymerase chain reaction assay for detection of Pneumocystis from bronchoalveolar lavage fluid. Diagn Microbiol Infect Dis 2006; 54:169-75. [PMID: 16423488 DOI: 10.1016/j.diagmicrobio.2005.08.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 08/08/2005] [Indexed: 11/19/2022]
Abstract
Pneumocystis jiroveci is an important cause of pneumonia in immunocompromised individuals. This organism cannot be cultured, and therefore, diagnosis relies on microscopic identification of the organism using stains or antibodies. Although simple, these tests are insensitive and require expertise for accurate interpretation. We developed a real-time polymerase chain reaction (PCR) assay that provides sensitive and objective detection of Pneumocystis from bronchoalveolar lavage fluid. Primers and fluorescence resonance energy transfer probes were developed that target the cdc2 gene of P. jiroveci. Assay sensitivity is 6 copies of target per microliter of sample. No cross-reactivity occurs with other pathogens, and the PCR assay has a 21% increase in clinical sensitivity as compared with Calcofluor white staining. The real-time PCR assay provides a sensitive, rapid, and objective method for the detection of Pneumocystis from bronchoalveolar lavage fluid.
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Affiliation(s)
- Rodney C Arcenas
- Division of Clinical Microbiology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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Espy MJ, Uhl JR, Sloan LM, Buckwalter SP, Jones MF, Vetter EA, Yao JDC, Wengenack NL, Rosenblatt JE, Cockerill FR, Smith TF. Real-time PCR in clinical microbiology: applications for routine laboratory testing. Clin Microbiol Rev 2006; 19:165-256. [PMID: 16418529 PMCID: PMC1360278 DOI: 10.1128/cmr.19.1.165-256.2006] [Citation(s) in RCA: 800] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Real-time PCR has revolutionized the way clinical microbiology laboratories diagnose many human microbial infections. This testing method combines PCR chemistry with fluorescent probe detection of amplified product in the same reaction vessel. In general, both PCR and amplified product detection are completed in an hour or less, which is considerably faster than conventional PCR detection methods. Real-time PCR assays provide sensitivity and specificity equivalent to that of conventional PCR combined with Southern blot analysis, and since amplification and detection steps are performed in the same closed vessel, the risk of releasing amplified nucleic acids into the environment is negligible. The combination of excellent sensitivity and specificity, low contamination risk, and speed has made real-time PCR technology an appealing alternative to culture- or immunoassay-based testing methods for diagnosing many infectious diseases. This review focuses on the application of real-time PCR in the clinical microbiology laboratory.
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Affiliation(s)
- M J Espy
- Mayo Clinic, 200 First St. SW, Hilton 470, Rochester, MN 55905, USA.
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14
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Strutt M, Smith M. Development of a real-time probe-based PCR assay for the diagnosis of Pneumocystis pneumonia. Med Mycol 2005; 43:343-7. [PMID: 16110780 DOI: 10.1080/13693780412331282340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
This paper describes the development of a rapid probe-based real-time polymerase chain reaction assay (PCR) for the diagnosis of Pneumocystis pneumonia. To develop the PCR, primers and fluorescent resonance energy transfer probes were designed after sequencing products obtained using previously published primers. This gave results that were concordant with conventional cytological staining techniques, but were available within 2 h instead of greater than 24 h.
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Affiliation(s)
- Matthew Strutt
- Health Protection Agency London, Guy's, Kings and St Thomas' School of Medicine, Kings College Hospital, London, UK.
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Brancart F, Rodriguez-Villalobos H, Fonteyne PA, Peres-Bota D, Liesnard C. Quantitative TaqMan PCR for detection of Pneumocystis jiroveci. J Microbiol Methods 2005; 61:381-7. [PMID: 15767014 DOI: 10.1016/j.mimet.2005.01.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 12/30/2004] [Accepted: 01/04/2005] [Indexed: 10/25/2022]
Abstract
We developed a quantitative real-time PCR assay for detection and quantification of Pneumocystis jiroveci in bronchoalveolar lavage (BAL) specimens based on primers and probe targeting the gene encoding beta-tubulin. The assay was able to detect 50 DNA copies per ml of a standard plasmid containing the target sequence. The intra- and interassay coefficients of variation were 0.46%-4.27% and 0.05-2.00% over 5 log(10) values. Fifty-seven controls of human, viruses, bacteria and fungi DNA samples were amplified and found negative. Fifty-three BAL samples sent to the laboratory for diagnosis of pneumocystosis were prospectively investigated by real-time PCR and direct microscopic examinations (DME) using Giemsa stain and direct immunofluorescence. All PCR negative samples were negative by microscopy. Among the 24 (45%) BAL found PCR positive, 8 were positive by microscopy (35%). The copy numbers of the target gene were between 4.4 x 10(3) and 2.8 x 10(6) per ml for the microscopically positive samples and between 8 and 9.2 x 10(3) per ml for the microscopically negative samples. In conclusion, we developed a rapid, sensitive and specific real time PCR for the diagnosis and quantification of Pneumocystis jiroveci in BAL samples.
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Affiliation(s)
- Françoise Brancart
- Laboratory of Microbiology, Erasme Hospital-ULB, 808 Route de Lennik, 1070 Brussels, Belgium.
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Linke MJ, Rebholz S, Collins M, Tanaka R, Cushion MT. Noninvasive method for monitoring Pneumocystis carinii pneumonia. Emerg Infect Dis 2004; 9:1613-6. [PMID: 14720405 PMCID: PMC3034349 DOI: 10.3201/eid0912.030270] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The progression of Pneumocystis carinii pneumonia was temporally monitored and quantified by real-time polymerase chain reaction of P. carinii–specific DNA in oral swabs and lung homogenates from infected rats. DNA levels correlated with the number of P. carinii organisms in the rats’ lungs, as enumerated by microscopic methods. This report is the first of a noninvasive, antemortem method that can be used to monitor infection in a host over time.
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Affiliation(s)
| | - Sandy Rebholz
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Margaret Collins
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Reiko Tanaka
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Melanie T. Cushion
- Veterans Affairs Medical Center, Cincinnati, Ohio, USA
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Wright TW, Pryhuber GS, Chess PR, Wang Z, Notter RH, Gigliotti F. TNF Receptor Signaling Contributes to Chemokine Secretion, Inflammation, and Respiratory Deficits duringPneumocystisPneumonia. THE JOURNAL OF IMMUNOLOGY 2004; 172:2511-21. [PMID: 14764724 DOI: 10.4049/jimmunol.172.4.2511] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) T cells contribute to the pathophysiology of Pneumocystis pneumonia (PcP) in a murine model of AIDS-related disease. The present studies were undertaken to more precisely define the mechanisms by which these immune cells mediate the inflammatory response that leads to lung injury. Experimental mice were depleted of either CD4(+) T cells or both CD4(+) and CD8(+) T cells and then infected with Pneumocystis: The CD4(+)-depleted mice had significantly greater pulmonary TNF-alpha levels than mice depleted of both CD4(+) and CD8(+) T cells. Elevated TNF-alpha levels were associated with increased lung concentrations of the chemokines RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant. To determine whether TNFR signaling was involved in the CD8(+) T cell-dependent chemokine response, TNFRI- and II-deficient mice were CD4(+) depleted and infected with Pneumocystis: TNFR-deficient mice had significantly reduced pulmonary RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant responses, reduced inflammatory cell recruitment to the alveoli, and reduced histological evidence of PcP-related alveolitis as compared with infected wild-type mice. Diminished pulmonary inflammation correlated with improved surfactant activity and improved pulmonary function in the TNFR-deficient mice. These data indicate that TNFR signaling is required for maximal CD8(+) T cell-dependent pulmonary inflammation and lung injury during PcP and also demonstrate that CD8(+) T cells can use TNFR signaling pathways to respond to an extracellular fungal pathogen.
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MESH Headings
- Animals
- Bronchoalveolar Lavage Fluid/chemistry
- Bronchoalveolar Lavage Fluid/cytology
- Bronchoalveolar Lavage Fluid/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/pathology
- Cell Movement/immunology
- Chemokines/biosynthesis
- Chemokines/metabolism
- Dose-Response Relationship, Immunologic
- Female
- Inflammation Mediators/physiology
- Lung/blood supply
- Lung/immunology
- Lung/pathology
- Lung/physiopathology
- Lung Compliance
- Mice
- Mice, SCID
- Mice, Transgenic
- Pneumonia, Pneumocystis/genetics
- Pneumonia, Pneumocystis/immunology
- Pneumonia, Pneumocystis/pathology
- Pneumonia, Pneumocystis/physiopathology
- Pulmonary Surfactants/metabolism
- Receptors, Tumor Necrosis Factor/deficiency
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Respiratory Function Tests
- Signal Transduction/genetics
- Signal Transduction/immunology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/physiology
- Up-Regulation/genetics
- Up-Regulation/immunology
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Affiliation(s)
- Terry W Wright
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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18
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Pryce TM, Kay ID, Palladino S, Heath CH. Real-time automated polymerase chain reaction (PCR) to detect Candida albicans and Aspergillus fumigatus DNA in whole blood from high-risk patients. Diagn Microbiol Infect Dis 2003; 47:487-96. [PMID: 14596967 DOI: 10.1016/s0732-8893(03)00139-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the development and evaluation of a real-time PCR assay using the LightCycler instrument for the detection of C. albicans and A. fumigatus DNA in whole blood. Recently published consensus criteria for the diagnosis of invasive fungal infection (IFI) were used for all patient samples. Unique and published primer pairs were developed and assessed for sensitivity, specificity, and reproducibility to detect C. albicans and A. fumigatus DNA in samples spiked with purified DNA, and whole blood samples from 8 high-risk patients and 45 negative controls. The real-time assay demonstrated an analytical sensitivity of 10 fg of purified C. albicans and A. fumigatus DNA and was found to be specific for each species. The standardized approach was highly reproducible and detected C. albicans and A. fumigatus DNA in two patients with proven IFI and in one patient with a possible IFI. In addition, we report for the first time the use of recently published international consensus criteria for the diagnosis of IFI in the evaluation of a mildly invasive fungal diagnostic assay. Standardized clinical criteria and a more standardized approach to detect fungal DNA in less invasive patient samples, may permit a more reliable comparison of future studies. A rapid real-time detection of fungal DNA in whole blood, combined with standard clinical markers of response, may be more useful for monitoring patients at risk of developing IFI than other diagnostic methods currently available.
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Affiliation(s)
- Todd M Pryce
- Department of Microbiology and Infectious Diseases, Royal Perth Hospital, Western, Perth, Australia.
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19
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Spiess B, Buchheidt D, Baust C, Skladny H, Seifarth W, Zeilfelder U, Leib-Mösch C, Mörz H, Hehlmann R. Development of a LightCycler PCR assay for detection and quantification of Aspergillus fumigatus DNA in clinical samples from neutropenic patients. J Clin Microbiol 2003; 41:1811-8. [PMID: 12734210 PMCID: PMC154665 DOI: 10.1128/jcm.41.5.1811-1818.2003] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The increasing incidence of invasive aspergillosis, a life-threatening infection in immunocompromised patients, emphasizes the need to improve the diagnostic tools for this disease. We established a LightCycler-based real-time PCR assay to detect and quantify rapidly, specifically, and sensitively Aspergillus fumigatus DNA in both bronchoalveolar lavage (BAL) and blood samples from high-risk patients. The primers and hybridization probes were derived from an A. fumigatus-specific sequence of the mitochondrial cytochrome b gene. The assay is linear in the range between 13.2 fg and 1.3 ng of A. fumigatus DNA, corresponding to 3 to 300,000 CFU per ml of BAL fluid or blood. No cross-amplification was observed with human DNA or with the DNA of fungal or bacterial pathogens. For clinical evaluation we investigated 10 BAL samples from nine neutropenic patients with malignant hematological diseases and 12 blood samples from seven neutropenic patients with malignant hematological diseases. Additionally, we tested one blood sample and one BAL sample from each of two neutropenic patients. In order to characterize the validity of the novel PCR assay, only samples that had shown positive results by a previously described sensitive and specific nested PCR assay were tested. Twelve of 12 BAL samples and 6 of 14 blood samples gave positive results by the LightCycler PCR assay. Eight of 14 blood samples gave negative results by the novel method. The LightCycler PCR-mediated quantification of the fungal burden showed 15 to 269,018 CFU per ml of BAL sample and 298 to 104,114 CFU per ml of blood sample. Twenty of 20 BAL samples and 50 of 50 blood samples from subjects without evidence of invasive pulmonary aspergillosis (IPA) were PCR negative. Compared to a previously described nested PCR assay, these preliminary data for the novel real-time PCR assay indicate a less sensitive rate of detection of IPA in high-risk patients, but the assay may be valuable for quantification of the fungal burden in individual clinical samples.
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Affiliation(s)
- Birgit Spiess
- III Medizinische Klinik, Universitätsklinikum Mannheim, University of Heidelberg, D-68305 Mannheim, Germany
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20
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White PL, Shetty A, Barnes RA. Detection of seven Candida species using the Light-Cycler system. J Med Microbiol 2003; 52:229-238. [PMID: 12621088 DOI: 10.1099/jmm.0.05049-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Due to the limitations of classical methods for the detection of systemic fungal infections and the high mortality rates associated with these infections, it has become essential to develop a quick, sensitive and specific detection assay. By using the Idaho Technologies Light-Cycler system, a qualitative real-time PCR system has been developed for the detection of the leading causes of systemic infection within the genus Candida. The sensitivity of the assay was comparable to previously described PCR methods (1-5 c.f.u. ml(-1)) and, by the use of a single Candida probe, it was able to detect, but not differentiate between, seven species of Candida (Candida albicans, Candida dubliniensis, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis and Candida tropicalis). Single-round amplification on the Light-Cycler allowed rapid turn-around of clinical samples (within one working day) and it was shown to be more sensitive than classical procedures, exposing 39 possible systemic infections that were not detected by blood culture.
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Affiliation(s)
- P Lewis White
- Department of Medical Microbiology and PHLS, University Hospital Wales, Heath Park, Cardiff CF14 4XN, UK
| | - Anjali Shetty
- Department of Medical Microbiology and PHLS, University Hospital Wales, Heath Park, Cardiff CF14 4XN, UK
| | - Rosemary A Barnes
- Department of Medical Microbiology and PHLS, University Hospital Wales, Heath Park, Cardiff CF14 4XN, UK
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21
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Semighini CP, de Camargo ZP, Puccia R, Goldman MHS, Goldman GH. Molecular identification of Paracoccidioides brasiliensis by 5' nuclease assay. Diagn Microbiol Infect Dis 2002; 44:383-6. [PMID: 12543545 DOI: 10.1016/s0732-8893(02)00472-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A PCR assay based on the 5' nuclease assay using a fluorescent probe derived from the sequence of the gene coding for the 43,000-Da (gp43) antigen was developed to detect Paracoccidioides brasiliensis. The assay could detect at least 10 copies of this DNA sequence, providing efficient accuracy to be useful for diagnosis of paracoccidioidomycosis.
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Affiliation(s)
- Camile P Semighini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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22
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Fukunaga H, Murakami T, Gondo T, Sugi K, Ishihara T. Sensitivity of acid-fast staining for Mycobacterium tuberculosis in formalin-fixed tissue. Am J Respir Crit Care Med 2002; 166:994-7. [PMID: 12359660 DOI: 10.1164/rccm.2111028] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Microscopic examination of tissue sections of mycobacterial lesions frequently results in few or no bacilli seen, even if the lesions appear active histologically. This might be due to the effects of the fixative fluid and/or organic solvent, both of which are conventionally used to make tissue sections for histopathology, on the acid-fast staining of bacteria. The present study was performed to examine how formalin and xylene lower the sensitivity of acid-fast staining for Mycobacterium tuberculosis and to clarify the meaning of the staining result in tissue sections. Microscopic observation of mycobacteria smeared on glass slides revealed that both of these agents greatly reduced the sensitivity of acid-fast staining. Moreover, the number of bacilli was calculated in 30 samples of paraffin-embedded granulomatous lesions using acid-fast microscopy and real-time polymerase chain reaction. The numbers of bacilli present that were estimated by real-time polymerase chain reaction were considerably higher than those counted with a microscope. These results suggest that the bacilli are frequently missed or underestimated with acid-fast microscopy on formalin-fixed, paraffin-embedded tissue.
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Affiliation(s)
- Hajime Fukunaga
- First Department of Pathology, Yamaguchi University School of Medicine, Yamaguchi, Japan.
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