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Giacobbe DR, Marelli C, Mora S, Guastavino S, Russo C, Brucci G, Limongelli A, Vena A, Mikulska M, Tayefi M, Peluso S, Signori A, Di Biagio A, Marchese A, Campi C, Giacomini M, Bassetti M. Early diagnosis of candidemia with explainable machine learning on automatically extracted laboratory and microbiological data: results of the AUTO-CAND project. Ann Med 2023; 55:2285454. [PMID: 38010342 PMCID: PMC10836245 DOI: 10.1080/07853890.2023.2285454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND Candidemia is associated with a heavy burden of morbidity and mortality in hospitalized patients. The availability of blood culture results could require up to 48-72 h after blood draw; thus, early treatment decisions are made in the absence of a definite diagnosis. METHODS In this retrospective study, we assessed the performance of different supervised machine learning algorithms for the early differential diagnosis of candidemia and bacteremia in adult patients on a large dataset automatically extracted within the AUTO-CAND project. RESULTS Overall, 12,483 episodes of candidemia (1275; 10%) or bacteremia (11,208; 90%) were included in the analysis. A random forest classifier achieved the best diagnostic performance for candidemia, with sensitivity 0.98 and specificity 0.65 on the training set (true skill statistic [TSS] = 0.63) and sensitivity 0.74 and specificity 0.57 on the test set (TSS = 0.31). Then, the random classifier was trained in the subgroup of patients with available serum β-D-glucan (BDG) and procalcitonin (PCT) values by exploiting the feature ranking learned in the entire dataset. Although no statistically significant differences were observed from the performance measures obtained by employing BDG and PCT alone, the performance measures of the classifier that included the features selected in the entire dataset, plus BDG and PCT, were the highest in most cases. CONCLUSIONS Random forest classifiers trained on large datasets of automatically extracted data have the potential to improve current diagnostic algorithms for candidemia. However, further development through implementation of automatically extracted clinical features may be necessary to achieve crucial improvements.
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Affiliation(s)
- Daniele Roberto Giacobbe
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Cristina Marelli
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Sara Mora
- Department of Informatics, Bioengineering, Robotics and System Engineering (DIBRIS), University of Genoa, Genoa, Italy
| | | | - Chiara Russo
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Giorgia Brucci
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Alessandro Limongelli
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Antonio Vena
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Malgorzata Mikulska
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Maryam Tayefi
- Norwegian Centre for E-Health Research, Tromsø, Norway
| | - Stefano Peluso
- Department of Statistics and Quantitative Methods, University of Milan - Bicocca, Milan, Italy
| | - Alessio Signori
- Section of Biostatistics, Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Antonio Di Biagio
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Marchese
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy
- Microbiology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Cristina Campi
- Department of Mathematics (DIMA), University of Genoa, Genoa, Italy
- Life Science Computational Laboratory (LISCOMP), IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Mauro Giacomini
- Department of Informatics, Bioengineering, Robotics and System Engineering (DIBRIS), University of Genoa, Genoa, Italy
| | - Matteo Bassetti
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Clinica Malattie Infettive, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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Eades CP, Bakri ARBA, Lau JCY, Moore CB, Novak-Frazer L, Richardson MD, Rautemaa-Richardson R. Comparison of β-1-3-D-Glucan and Candida Mannan Biomarker Assays with Serological Tests for the Diagnosis of Candidemia. J Fungi (Basel) 2023; 9:813. [PMID: 37623584 PMCID: PMC10455369 DOI: 10.3390/jof9080813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023] Open
Abstract
Invasive candidiasis, including bloodstream infection (candidemia), encompasses the most severe forms of Candida infection. Several species-specific and non-specific serological assays are commercially available to aid in diagnosis. This study compared the performance of five such biomarker assays. Serum samples from 14 patients with proven or probable invasive candidiasis, and from 10 control patients, were included in the analysis. A total of 50 serum samples were tested using C. albicans germ tube antibody (CAGTA) assay (Vircell), C. albicans IgM, C. albicans IgG and Candida mannan assays (Dynamiker Biotechnology). Among these samples, the β-1-3-D-glucan (BDG) assay (Fungitell), a laboratory standard for the diagnosis of invasive candidiasis, was positive in 20 (40%), intermediate in five (10%) and negative in 25 (50%). In cases of proven or probable candidemia, the sensitivity and specificity of the BDG assay was 86% and 80%, respectively; the Candida mannan assay, 14% and 86%; the CAGTA test, 57% and 60%; the C. albicans IgM assay, 71% and 60%; and C. albicans IgG assay 29% and 90%. In 4/8 (50%) cases with multiple serum samples, C. albicans IgM was positive sooner than BDG. Thus, when used as a rule-out test for invasive candidiasis, our data suggest that the C. albicans IgM assay may assist antifungal stewardship (over serum BDG).
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Affiliation(s)
- Christopher P. Eades
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK;
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Ahmed Rafezzan Bin Ahmed Bakri
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Jeffrey C. Y. Lau
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Caroline B. Moore
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
| | - Lilyann Novak-Frazer
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Malcolm D. Richardson
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
- Manchester Fungal Infection Group (MFIG), Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9NT, UK
| | - Riina Rautemaa-Richardson
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK;
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, NIHR Manchester Biomedical Research Centre (BRC) at the Manchester Academic Health Science Centre, The University of Manchester and Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK (J.C.Y.L.); (L.N.-F.); (M.D.R.)
- Mycology Reference Centre Manchester (MRCM), ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
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Morovati H, Kord M, Ahmadikia K, Eslami S, Hemmatzadeh M, Kurdestani KM, Khademi M, Darabian S. A Comprehensive Review of Identification Methods for Pathogenic Yeasts: Challenges and Approaches. Adv Biomed Res 2023; 12:187. [PMID: 37694259 PMCID: PMC10492613 DOI: 10.4103/abr.abr_375_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 09/12/2023] Open
Abstract
Given the increasing incidence of yeast infections and the presence of drug-resistant isolates, accurate identification of the pathogenic yeasts is essential for the management of yeast infections. In this review, we tried to introduce the routine and novel techniques applied for yeast identification. Laboratory identification methods of pathogenic yeast are classified into three categories; I. conventional methods, including microscopical and culture-base methods II. biochemical/physiological-processes methods III. molecular methods. While conventional and biochemical methods require more precautions and are not specific in some cases, molecular diagnostic methods are the optimum tools for diagnosing pathogenic yeasts in a short time with high accuracy and specificity, and having various methods that cover different purposes, and affordable costs for researchers. Nucleotide sequencing is a reference or gold standard for identifying pathogenic yeasts. Since it is an expensive method, it is not widely used in developing countries. However, novel identification techniques are constantly updated, and we recommend further studies in this field. The results of this study will guide researchers in finding more accurate diagnostic method(s) for their studies in a short period of time.
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Affiliation(s)
- Hamid Morovati
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Kord
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Kazem Ahmadikia
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Saba Eslami
- Central Research Laboratory, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Masoumeh Hemmatzadeh
- Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Kian M. Kurdestani
- Department of Microbiology, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
| | | | - Sima Darabian
- Department of Medical Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
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Fernández-Manteca MG, Ocampo-Sosa AA, Ruiz de Alegría-Puig C, Pía Roiz M, Rodríguez-Grande J, Madrazo F, Calvo J, Rodríguez-Cobo L, López-Higuera JM, Fariñas MC, Cobo A. Automatic classification of Candida species using Raman spectroscopy and machine learning. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 290:122270. [PMID: 36580749 DOI: 10.1016/j.saa.2022.122270] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/29/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
One of the problems that most affect hospitals is infections by pathogenic microorganisms. Rapid identification and adequate, timely treatment can avoid fatal consequences and the development of antibiotic resistance, so it is crucial to use fast, reliable, and not too laborious techniques to obtain quick results. Raman spectroscopy has proven to be a powerful tool for molecular analysis, meeting these requirements better than traditional techniques. In this work, we have used Raman spectroscopy combined with machine learning algorithms to explore the automatic identification of eleven species of the genus Candida, the most common cause of fungal infections worldwide. The Raman spectra were obtained from more than 220 different measurements of dried drops from pure cultures of each Candida species using a Raman Confocal Microscope with a 532 nm laser excitation source. After developing a spectral preprocessing methodology, a study of the quality and variability of the measured spectra at the isolate and species level, and the spectral features contributing to inter-class variations, showed the potential to discriminate between those pathogenic yeasts. Several machine learning and deep learning algorithms were trained using hyperparameter optimization techniques to find the best possible classifier for this spectral data, in terms of accuracy and lowest possible overfitting. We found that a one-dimensional Convolutional Neural Network (1-D CNN) could achieve above 80 % overall accuracy for the eleven classes spectral dataset, with good generalization capabilities.
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Affiliation(s)
| | - Alain A Ocampo-Sosa
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - Carlos Ruiz de Alegría-Puig
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain; CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - María Pía Roiz
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - Jorge Rodríguez-Grande
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - Fidel Madrazo
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain
| | - Jorge Calvo
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain; CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Rodríguez-Cobo
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Photonics Engineering Group, Universidad de Cantabria, Santander, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Madrid, Spain
| | - José Miguel López-Higuera
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Photonics Engineering Group, Universidad de Cantabria, Santander, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Madrid, Spain
| | - María Carmen Fariñas
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain; Servicio de Enfermedades Infecciosas, Hospital Universitario Marqués de Valdecilla, Santander, Spain; Departamento de Medicina y Psiquiatría, Universidad de Cantabria, Santander, Spain
| | - Adolfo Cobo
- Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander, Spain; Photonics Engineering Group, Universidad de Cantabria, Santander, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Madrid, Spain.
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Varghese JA, Guhan S, Zheng L. Emerging Fungal Infections and Cutaneous Manifestations in Immunosuppressed Patients. CURRENT DERMATOLOGY REPORTS 2023. [DOI: 10.1007/s13671-023-00386-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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Validation of an Automated System for the Extraction of a Wide Dataset for Clinical Studies Aimed at Improving the Early Diagnosis of Candidemia. Diagnostics (Basel) 2023; 13:diagnostics13050961. [PMID: 36900105 PMCID: PMC10001256 DOI: 10.3390/diagnostics13050961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
There is increasing interest in assessing whether machine learning (ML) techniques could further improve the early diagnosis of candidemia among patients with a consistent clinical picture. The objective of the present study is to validate the accuracy of a system for the automated extraction from a hospital laboratory software of a large number of features from candidemia and/or bacteremia episodes as the first phase of the AUTO-CAND project. The manual validation was performed on a representative and randomly extracted subset of episodes of candidemia and/or bacteremia. The manual validation of the random extraction of 381 episodes of candidemia and/or bacteremia, with automated organization in structured features of laboratory and microbiological data resulted in ≥99% correct extractions (with confidence interval < ±1%) for all variables. The final automatically extracted dataset consisted of 1338 episodes of candidemia (8%), 14,112 episodes of bacteremia (90%), and 302 episodes of mixed candidemia/bacteremia (2%). The final dataset will serve to assess the performance of different ML models for the early diagnosis of candidemia in the second phase of the AUTO-CAND project.
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Moteshareie H, Hassen WM, Dirieh Y, Groulx E, Dubowski JJ, Tayabali AF. Rapid, Sensitive, and Selective Quantification of Bacillus cereus Spores Using xMAP Technology. Microorganisms 2022; 10:microorganisms10071408. [PMID: 35889128 PMCID: PMC9319878 DOI: 10.3390/microorganisms10071408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 12/04/2022] Open
Abstract
Bacillus cereus is a spore-forming ubiquitous bacterium notable as a food poisoning agent. Detection of B. cereus spores using selective media is laborious and non-specific. Herein, the quantitative detection of B. cereus spores was investigated with commercial antibodies and published aptamer sequences. Several detection reagents were screened for affinity to Bacillus collagen-like protein A (BclA), an abundant exosporium glycoprotein. Sensitivity and selectivity toward B. cereus spores were tested using immunoassays and multi-analyte profiling (xMAP). A recombinant antibody developed in llama against BclA protein showed B. cereus spore selectivity and sensitivity between 102 and 105 spores/mL using xMAP. DNA aptamer sequences demonstrated sensitivity from 103 to 107 spores/mL and no cross-reaction to B. megaterium and B. subtilis. Selectivity for B. cereus spores was also demonstrated in a mixture of several diverse microorganisms and within a food sample with no compromise of sensitivity. As proof of concept for multiplexed measurement of human pathogens, B. cereus and three other microorganisms, E. coli, P. aeruginosa, and S. cerevisiae, were simultaneously detected using xMAP. These data support the development of a rapid, sensitive, and selective system for quantitation of B. cereus spores and multiplexed monitoring of human pathogens in complex matrices.
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Affiliation(s)
- Houman Moteshareie
- Department of Electrical and Computer Engineering, Interdisciplinary Institute for Technological Innovation (3IT), Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (H.M.); (W.M.H.); (J.J.D.)
| | - Walid M. Hassen
- Department of Electrical and Computer Engineering, Interdisciplinary Institute for Technological Innovation (3IT), Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (H.M.); (W.M.H.); (J.J.D.)
| | - Yasmine Dirieh
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, ON K1A 0K9, Canada; (Y.D.); (E.G.)
| | - Emma Groulx
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, ON K1A 0K9, Canada; (Y.D.); (E.G.)
| | - Jan J. Dubowski
- Department of Electrical and Computer Engineering, Interdisciplinary Institute for Technological Innovation (3IT), Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (H.M.); (W.M.H.); (J.J.D.)
| | - Azam F. Tayabali
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Environmental Health Centre, Health Canada, Ottawa, ON K1A 0K9, Canada; (Y.D.); (E.G.)
- Correspondence:
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Moteshareie H, Hassen WM, Vermette J, Dubowski JJ, Tayabali AF. Strategies for capturing Bacillus thuringiensis spores on surfaces of (001) GaAs-based biosensors. Talanta 2022; 236:122813. [PMID: 34635209 DOI: 10.1016/j.talanta.2021.122813] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/18/2021] [Accepted: 08/16/2021] [Indexed: 12/17/2022]
Abstract
Bacillus thuringiensis (Bt) is used as a bioinsecticide since it effectively kills insect larvae. Bt is also genetically similar to Bacillus cereus (Bc), a well recognized foodborne human pathogen; they are both members of the Bacillus cereus group (BC group). Although approved Bt bioinsecticide products have been confirmed to be non-pathogenic to humans, close monitoring of Bt during dissemination is important for cost considerations and to limit impact on biodiversity towards nontarget organisms. As such, developing rapid, sensitive, and specific tools for quantitative detection of Bt spores during and following spray operations is highly desirable. The goals of this study were to investigate commercially available detection reagents for sensitivity and selectivity in detecting Bt spores, and then functionalize a surface of (001) GaAs used in photonic biosensing. To achieve these goals, we (1) screened commercial antibodies for their capacity to bind recombinant proteins from Bt spores, (2) screened antibodies and aptamers for their sensitivity and selectivity against Bt spores, and (3) tested the efficiency of selected antibodies and aptamers in capturing Bt spores on the surface of functionalized GaAs biochips. Seven genes encoding Bt spore proteins were cloned and expressed in Escherichia coli. The binding of each purified spore antigen was tested by commercially available polyclonal and monoclonal antibodies claimed to exclusively target spores. Of the seven targets, Bacillus collagen-like protein A, was the most abundant protein on Bt spores and demonstrated the strongest binding affinity to all test antibodies. The commercial antibodies (Abs) were also tested for specificity to BC Group versus non-BC Group spores. Three of six commercial antibodies showed selectivity to Bt spores, with recombinant Abs providing the most robust lower range of detection (102 to 6 × 103 spores/mL). The sensitivity and selectivity of three published DNA aptamer sequences demonstrated a wide range of detection sensitivity for Bt spores. Two of the three test aptamers also showed reasonable selectivity towards Bt spores while the third demonstrated reactivity to non-BC Group B. megaterium and B. subtilis. Of the reagents tested, a thiolated aptamer and llama recombinant Ab showed highest Bt spore capture efficiency as measured by spore coverage of the GaAs surface. These results confirm that the selected aptamer and llama rAb can be considered strong candidates for the development of GaAs-based biosensing devices.
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Affiliation(s)
- Houman Moteshareie
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada; Interdisciplinary Institute for Technological Innovation (3IT), CNRS UMI-3463, Laboratory for Quantum Semiconductors and Photon-based BioNanotechnology, Department of Electrical and Computer Engineering, Sherbrooke, Québec, Canada.
| | - Walid M Hassen
- Interdisciplinary Institute for Technological Innovation (3IT), CNRS UMI-3463, Laboratory for Quantum Semiconductors and Photon-based BioNanotechnology, Department of Electrical and Computer Engineering, Sherbrooke, Québec, Canada
| | - Jonathan Vermette
- Interdisciplinary Institute for Technological Innovation (3IT), CNRS UMI-3463, Laboratory for Quantum Semiconductors and Photon-based BioNanotechnology, Department of Electrical and Computer Engineering, Sherbrooke, Québec, Canada
| | - Jan J Dubowski
- Interdisciplinary Institute for Technological Innovation (3IT), CNRS UMI-3463, Laboratory for Quantum Semiconductors and Photon-based BioNanotechnology, Department of Electrical and Computer Engineering, Sherbrooke, Québec, Canada.
| | - Azam F Tayabali
- Biotechnology Laboratory, Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada; Interdisciplinary Institute for Technological Innovation (3IT), CNRS UMI-3463, Laboratory for Quantum Semiconductors and Photon-based BioNanotechnology, Department of Electrical and Computer Engineering, Sherbrooke, Québec, Canada.
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Gupta Y, Ghrera AS. Recent advances in gold nanoparticle-based lateral flow immunoassay for the detection of bacterial infection. Arch Microbiol 2021; 203:3767-3784. [PMID: 34086107 DOI: 10.1007/s00203-021-02357-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/24/2021] [Accepted: 05/03/2021] [Indexed: 12/17/2022]
Abstract
Diagnosis of bacterial infections (BI) is becoming an increasingly difficult task in clinical practice due to their high prevalence and frequency, as well as the growth of antibiotic resistance worldwide. World Health Organization (WHO) reported antibiotic resistance is a major public health problem. BI becomes difficult or impossible to treat when the bacteria acquire immunity against antibiotics. Thus, there is a need for a quick and accurate technique to detect infection. Lateral flow immunoassay (LFIA) is an ideal technique for point-of-care testing of a disease or pathological changes inside the human body. In recent years, several LFIA based strips are being used for the detection of BI by targeting specific analytes which may range from the causative bacterium, whole-cell, DNA, or biomarker. Numerous nanoparticles like lipid-based nanoparticles, polymeric nanoparticles, and inorganic nanoparticles such as quantum dots, magnetic, ceramic, and metallic nanoparticles (copper, silver gold, iron) are widely being used in the advanced treatment of BI. Out of these gold nanoparticle (AuNPs), is being used for detection BI more effectively than other nanoparticles due to their surface functionalization, extraordinary chemical stability, biorecognition, and signal amplification properties and help to improve in conjugation with capture antibodies, and act as a color marker with unique optical properties on LFIA strips. Herein, a review that provides an overview of the principle of LFIA, how LFIA based strip is developed, and how it is helpful to detect a specific biomarker for bedside detection of the BI.
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Affiliation(s)
- Yachana Gupta
- Applied Science Department, The NorthCap University, Gurugram, India
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Bassetti M, Azoulay E, Kullberg BJ, Ruhnke M, Shoham S, Vazquez J, Giacobbe DR, Calandra T. EORTC/MSGERC Definitions of Invasive Fungal Diseases: Summary of Activities of the Intensive Care Unit Working Group. Clin Infect Dis 2021; 72:S121-S127. [PMID: 33709127 DOI: 10.1093/cid/ciaa1751] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The EORTC/MSGERC recently revised and updated the consensus definitions of invasive fungal disease (IFD). These definitions primarily focus on patients with cancer and stem cell or solid-organ transplant patients. They may therefore not be suitable for intensive care unit (ICU) patients. More in detail, while the definition of proven IFD applies to a broad range of hosts, the categories of probable and possible IFD were primarily designed for classical immunocompromised hosts and may therefore not be ideal for other populations. Moreover, the scope of the possible category of IFD has been diminished in the recently revised definitions for classically immunocompromised hosts. Diagnosis of IFD in the ICU presents many challenges, which are different for invasive candidiasis and for invasive aspergillosis. The aim of this article is to review progresses made in recent years and difficulties remaining in the development of definitions applicable in the ICU setting.
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Affiliation(s)
- Matteo Bassetti
- Infectious Diseases Unit, Ospedale Policlinico San Martino-IRCCS, Genoa, Italy.,Department of Health Sciences, University of Genoa, Genoa, Italy
| | - Elie Azoulay
- Medical ICU, APHP, Saint-Louis Hospital, Paris, France.,Université de Paris, Paris, France
| | - Bart-Jan Kullberg
- Department of Medicine and Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Markus Ruhnke
- Division of Hematology, Oncology and Palliative Care, Department of Internal Medicine, Helios Klinikum Aue, Aue, Germany
| | - Shmuel Shoham
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jose Vazquez
- Department of Medicine, Division of Infectious Diseases, Medical College of Georgia/Augusta University, Augusta, Georgia, USA
| | | | - Thierry Calandra
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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White PL, Posso R, Parr C, Price JS, Finkelman M, Barnes RA. The Presence of (1→3)-β-D-Glucan as Prognostic Marker in Patients After Major Abdominal Surgery. Clin Infect Dis 2020; 73:e1415-e1422. [PMID: 32914187 DOI: 10.1093/cid/ciaa1370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/07/2020] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND While the serological detection of (1→3)-β-D-glucan (BDG) can indicate invasive fungal disease (IFD), false positivity occurs. Nevertheless, the presence of BDG can still be recognized by the host's innate immune system and persistent BDG antigenemia, in the absence of IFD, can result in deleterious proinflammatory immune responses. METHODS During the XXX (INTENSE) study into the preemptive use of micafungin to prevent invasive candidiasis (IC) after abdominal surgery, the serum burden of BDG was determined to aid diagnosis of IC. Data from the INTENSE study were analyzed to determine whether BDG was associated with organ failure and patient mortality, while accounting for the influences of IC and antifungal therapy. RESULTS A BDG concentration >100 pg/mL was associated with a significantly increased Sequential Organ Failure Assessment score (≤100 pg/mL: 2 vs >100 pg/mL: 5; P < .0001) and increased rates of mortality (≤100 pg/mL: 13.7% vs >100 pg/mL: 39.0%; P = .0002). Multiple (≥2) positive results >100 pg/mL or a BDG concentration increasing >100 pg/mL increased mortality (48.1%). The mortality rate in patients with IC and a BDG concentration >100 pg/mL and ≤100 pg/mL was 42.3% and 25.0%, respectively. The mortality rate in patients without IC but a BDG concentration >100 pg/mL was 37.3%. The use of micafungin did not affect the findings. CONCLUSIONS The presence of persistent or increasing BDG in the patient's circulation is associated with significant morbidity and mortality after abdominal surgery, irrespective of IC. The potential lack of a specific therapeutic focus has consequences when trying to manage these patients, and when designing clinical trials involving patients where host-associated BDG concentrations may be elevated. CLINICAL TRIALS REGISTRATION NCT01122368.
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Affiliation(s)
- P Lewis White
- Mycology Reference Laboratory, Microbiology Cardiff, Public Health Wales, Cardiff, United Kingdom
| | - Raquel Posso
- Mycology Reference Laboratory, Microbiology Cardiff, Public Health Wales, Cardiff, United Kingdom
| | - Christian Parr
- Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Jessica S Price
- Mycology Reference Laboratory, Microbiology Cardiff, Public Health Wales, Cardiff, United Kingdom
| | | | - Rosemary A Barnes
- Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Cardiff, United Kingdom
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Kashiha A, Setayesh N, Panahi Y, Ahmadi A, Soltany-Rezaee-Rad M, Najafi A, Rouini MR, Namipashaki A, Sahebkar A, Mojtahedzadeh M. Prevalence of candidemia and associated candida subtypes following severe sepsis in non-neutropenic critically ill patients. ACTA BIO-MEDICA : ATENEI PARMENSIS 2018; 89:193-202. [PMID: 29957751 PMCID: PMC6179014 DOI: 10.23750/abm.v89i2.5385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 05/25/2016] [Indexed: 11/23/2022]
Abstract
Background: Invasive candidiasis management through the rapid initiation of appropriate antifungal therapy has been shown to be associated with the better prognosis, improved clinical outcome and reduced mortality in critically ill patients. Therefore, selection of an appropriate antifungal therapy should be based on the distribution of candida species and the pattern of antifungal resistance. This study aimed to assess the prevalence of candidemia and associated subtypes following severe sepsis in non-neutropenic critically ill patients. Methods: This study was a cross-sectional study that was conducted on severe sepsis patients stayed at least seven days in intensive care unit. Patients less than 18 years old, pregnant and breastfeeding patients, immunocompromised patients, neutropenic patients, patients with concurrent use of antifungal medicines and cytotoxic agents were excluded.To asses the candidemia, one mililiter of patients’ blood sample was collected. Sample analysis was performed by Real-Time PCR and high resolution melting curve analysis method. Results: Thirty-one critically ill patients were recruited in this study over 12-month period. Candidemia with a detection limit of 100 pg per 0.2 ml blood sample was not recognized in any of the included patients. Conclusion: The present result indicates low incidence of candidemia in the targeted intensive care units, but other factors such as small sample size, exclusion of patients with compromised immune system and the low fungal load at the time of sampling may also account for our observation. (www.actabiomedica.it)
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Affiliation(s)
- Arefeh Kashiha
- Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | - Neda Setayesh
- Department of Pharmaceutical Biotechnology and Pharmaceutical Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | | | - Arezoo Ahmadi
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mohammad Soltany-Rezaee-Rad
- Department of Pharmaceutical Biotechnology and Pharmaceutical Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | - Atabak Najafi
- Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mohammad Reza Rouini
- epartment of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences.
| | - Atefeh Namipashaki
- Department of Medical Biotechology, Faculty of Advanced Technologies in Medicine, Tehran University of Medical Sciences. Tehran, Iran.
| | | | - Mojtaba Mojtahedzadeh
- Clinical Pharmacy Department, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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13
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Morton CO, White PL, Barnes RA, Klingspor L, Cuenca-Estrella M, Lagrou K, Bretagne S, Melchers W, Mengoli C, Caliendo AM, Cogliati M, Debets-Ossenkopp Y, Gorton R, Hagen F, Halliday C, Hamal P, Harvey-Wood K, Jaton K, Johnson G, Kidd S, Lengerova M, Lass-Florl C, Linton C, Millon L, Morrissey CO, Paholcsek M, Talento AF, Ruhnke M, Willinger B, Donnelly JP, Loeffler J. Determining the analytical specificity of PCR-based assays for the diagnosis of IA: What is Aspergillus? Med Mycol 2018; 55:402-413. [PMID: 28339744 DOI: 10.1093/mmy/myw093] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/27/2016] [Indexed: 11/14/2022] Open
Abstract
A wide array of PCR tests has been developed to aid the diagnosis of invasive aspergillosis (IA), providing technical diversity but limiting standardisation and acceptance. Methodological recommendations for testing blood samples using PCR exist, based on achieving optimal assay sensitivity to help exclude IA. Conversely, when testing more invasive samples (BAL, biopsy, CSF) emphasis is placed on confirming disease, so analytical specificity is paramount. This multicenter study examined the analytical specificity of PCR methods for detecting IA by blind testing a panel of DNA extracted from a various fungal species to explore the range of Aspergillus species that could be detected, but also potential cross reactivity with other fungal species. Positivity rates were calculated and regression analysis was performed to determine any associations between technical specifications and performance. The accuracy of Aspergillus genus specific assays was 71.8%, significantly greater (P < .0001) than assays specific for individual Aspergillus species (47.2%). For genus specific assays the most often missed species were A. lentulus (25.0%), A. versicolor (24.1%), A. terreus (16.1%), A. flavus (15.2%), A. niger (13.4%), and A. fumigatus (6.2%). There was a significant positive association between accuracy and using an Aspergillus genus PCR assay targeting the rRNA genes (P = .0011). Conversely, there was a significant association between rRNA PCR targets and false positivity (P = .0032). To conclude current Aspergillus PCR assays are better suited for detecting A. fumigatus, with inferior detection of most other Aspergillus species. The use of an Aspergillus genus specific PCR assay targeting the rRNA genes is preferential.
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Affiliation(s)
| | | | | | | | | | - Katrien Lagrou
- University Hospitals Leuven, Department of Laboratory Medicine and National Reference Center for Mycosis, Leuven, Belgium, Belgium
| | - Stéphane Bretagne
- Paris Diderot, Sorbonne Paris Cité University, Faculty of Medicine, Paris, France
| | | | | | - Angela M Caliendo
- Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island and Aspergillus Technology Consortium, USA
| | - Massimo Cogliati
- Dip. Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy
| | | | | | - Ferry Hagen
- Canisius-Wilhelmina Hospital, Nijmegen. The Netherlands
| | - Catriona Halliday
- Clinical Mycology Reference Laboratory, Pathology West, Westmead, Australia
| | - Petr Hamal
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | | | - Katia Jaton
- Institute of Microbiology, University Hospital of Lausanne, Switzerland
| | - Gemma Johnson
- Blizard Institute of Cell and Molecular Science, Queen Mary University of London, London, United Kingdom
| | - Sarah Kidd
- National Mycology Reference Centre, SA Pathology, Adelaide. Australia
| | - Martina Lengerova
- Department of Internal Medicine - Hematology and Oncology, University Hospital Brno, Brno, Czech Republic
| | | | - Chris Linton
- UK Mycology Reference Lab, Public Health England, Bristol, United Kingdom
| | - Laurence Millon
- Laboratoire de Parasitologie-Mycologie Centre Hospitalier Universitaire, Besançon, France
| | | | - Melinda Paholcsek
- University of Debrecen Medical and Health Science Center, Debrecen. Hungary
| | - Alida Fe Talento
- Department of Clinical Microbiology, Trinity College, Dublin, Ireland
| | - Markus Ruhnke
- Charité Medical School, University of Berlin, Berlin. Germany
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14
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Leeflang MMG, Debets‐Ossenkopp YJ, Wang J, Visser CE, Scholten RJPM, Hooft L, Bijlmer HA, Reitsma JB, Zhang M, Bossuyt PMM, Vandenbroucke‐Grauls CM. Galactomannan detection for invasive aspergillosis in immunocompromised patients. Cochrane Database Syst Rev 2015; 2015:CD007394. [PMID: 26716951 PMCID: PMC6483812 DOI: 10.1002/14651858.cd007394.pub2] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Invasive aspergillosis is the most common life-threatening opportunistic invasive mycosis in immunocompromised patients. A test for invasive aspergillosis should neither be too invasive nor too great a burden for the already weakened patient. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) seems to have the potential to meet both requirements. OBJECTIVES To obtain summary estimates of the diagnostic accuracy of galactomannan detection in serum for the diagnosis of invasive aspergillosis. SEARCH METHODS We searched MEDLINE, EMBASE and Web of Science with both MeSH terms and text words for both aspergillosis and the sandwich ELISA. We checked the reference lists of included studies and review articles for additional studies. We conducted the searches in February 2014. SELECTION CRITERIA We included cross-sectional studies, case-control designs and consecutive series of patients assessing the diagnostic accuracy of galactomannan detection for the diagnosis of invasive aspergillosis in patients with neutropenia or patients whose neutrophils are functionally compromised. The reference standard was composed of the criteria given by the European Organization for Research and Treatment of Cancer (EORTC) and the Mycoses Study Group (MSG). DATA COLLECTION AND ANALYSIS Two review authors independently assessed quality and extracted data. We carried out meta-analysis using the bivariate method. We investigated sources of heterogeneity by adding potential sources of heterogeneity to the model as covariates. MAIN RESULTS We included 54 studies in the review (50 in the meta-analyses), containing 5660 patients, of whom 586 had proven or probable invasive aspergillosis. When using an optical density index (ODI) of 0.5 as a cut-off value, the sensitivity of the test was 82% (73% to 90%) and the specificity was 81% (72% to 90%). At a cut-off value of 1.0 ODI, the sensitivity was 72% (65% to 80%) and the specificity was 88% (84% to 92%). At a cut-off value of 1.5 ODI, the sensitivity was 61% (47% to 75%) and the specificity was 93% (89% to 97%). None of the potential sources of heterogeneity had a statistically significant effect on either sensitivity or specificity. AUTHORS' CONCLUSIONS If we used the test at a cut-off value of 0.5 ODI in a population of 100 patients with a disease prevalence of 9% (overall median prevalence), two patients who have invasive aspergillosis would be missed (sensitivity 82%, 18% false negatives), and 17 patients would be treated unnecessarily or referred unnecessarily for further testing (specificity 81%, 19% false negatives). If we used the test at a cut-off value of 1.5 in the same population, that would mean that four invasive aspergillosis patients would be missed (sensitivity 61%, 39% false negatives), and six patients would be treated or referred for further testing unnecessarily (specificity 93%, 7% false negatives). These numbers should, however, be interpreted with caution because the results were very heterogeneous.
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Affiliation(s)
- Mariska MG Leeflang
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsP.O. Box 22700AmsterdamNetherlands1100 DE
| | - Yvette J Debets‐Ossenkopp
- VU University Medical CenterDepartment of Medical Microbiology and Infection ControlPO Box 7057AmsterdamNetherlands1007 MB
| | - Junfeng Wang
- Academic Medical CenterDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsMeibergdreef 9AmsterdamNetherlands1105 AZ
| | - Caroline E Visser
- Academic Medical CentreDepartment of Medical MicrobiologyAmsterdamNetherlands
| | - Rob JPM Scholten
- Julius Center for Health Sciences and Primary Care / University Medical Center UtrechtCochrane NetherlandsRoom Str. 6.126P.O. Box 85500UtrechtNetherlands3508 GA
| | - Lotty Hooft
- Julius Center for Health Sciences and Primary Care / University Medical Center UtrechtCochrane NetherlandsRoom Str. 6.126P.O. Box 85500UtrechtNetherlands3508 GA
| | - Henk A Bijlmer
- Bronovo HospitalDepartment of Clinical Microbiology and Infection ControlThe HagueNetherlands
| | - Johannes B Reitsma
- University Medical Center UtrechtJulius Center for Health Sciences and Primary CarePO Box 85500UtrechtNetherlands3508 GA Utrecht
| | - Mingming Zhang
- West China Hospital, Sichuan UniversityChinese Cochrane Centre, Chinese Evidence‐Based Medicine CentreNo. 37, Guo Xue XiangChengduSichuanChina610041
| | - Patrick MM Bossuyt
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsP.O. Box 22700AmsterdamNetherlands1100 DE
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Rodrigues AM, de Hoog GS, de Camargo ZP. Molecular Diagnosis of Pathogenic Sporothrix Species. PLoS Negl Trop Dis 2015; 9:e0004190. [PMID: 26623643 PMCID: PMC4666615 DOI: 10.1371/journal.pntd.0004190] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/02/2015] [Indexed: 01/08/2023] Open
Abstract
Background Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective. Methodology We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens. Results Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10–100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals. Conclusions This PCR-based method could successfully detect and identify a single species in samples from cultures and from clinical specimens. The method proved to be simple, high throughput, sensitive, and accurate for diagnosing sporotrichosis. Sporotrichosis, a disease caused by infections from Sporothrix species, primarily affects warm-blooded animals, particularly humans and cats. Sporotrichosis is emerging as a global threat, with high incidences in Brazil and China. The gold standard for diagnosing sporotrichosis is microscopic characterization of the pathogen isolated in culture. This methodology is tedious and time-consuming. Moreover, closely related Sporothrix species are often misidentified, due to similar phenotypic characteristics. The introduction of dissimilar species with specific geographic distributions, host predilections, virulence, and antifungal susceptibilities, has made species-level identification of Sporothrix mandatory. To facilitate meeting this requirement, we developed a PCR-based method for detecting and identifying Sporothrix species. We designed species-specific primers for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and Ophiostoma stenoceras. With this method, we could detect as little as 1 pg and 10 fg (depending on the species) of Sporothrix DNA derived from isolated cultures. Furthermore, we successfully detected S. brasiliensis and S. schenckii DNA in tissue samples derived from a murine model of disseminated sporotrichosis. These species-specific primers can be applied in epidemiology, clinical diagnosis, and experimental studies of sporotrichosis. Improvements in early diagnosis and surveillance systems may facilitate rapid identification and control of future outbreaks.
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Affiliation(s)
- Anderson Messias Rodrigues
- Departamento de Microbiologia, Imunologia e Parasitologia, Disciplina de Biologia Celular, Universidade Federal de São Paulo (UNIFESP), São Paulo, São Paulo, Brazil
- * E-mail: (AMR); (ZPC)
| | | | - Zoilo Pires de Camargo
- Departamento de Microbiologia, Imunologia e Parasitologia, Disciplina de Biologia Celular, Universidade Federal de São Paulo (UNIFESP), São Paulo, São Paulo, Brazil
- * E-mail: (AMR); (ZPC)
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Application of Culture-Independent Rapid Diagnostic Tests in the Management of Invasive Candidiasis and Cryptococcosis. J Fungi (Basel) 2015; 1:217-251. [PMID: 29376910 PMCID: PMC5753112 DOI: 10.3390/jof1020217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/17/2015] [Accepted: 08/17/2015] [Indexed: 12/26/2022] Open
Abstract
The diagnosis of invasive candidiasis (IC) and cryptococcosis is often complicated by slow and insensitive culture-based methods. Such delay results in poor outcomes due to the lack of timely therapeutic interventions. Advances in serological, biochemical, molecular and proteomic approaches have made a favorable impact on this process, improving the timeliness and accuracy of diagnosis with resultant improvements in outcome. This paper will serve as an overview of recent developments in the diagnostic approaches to infections due to these important yeast-fungi.
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17
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Bhunia AK. One day to one hour: how quickly can foodborne pathogens be detected? Future Microbiol 2015; 9:935-46. [PMID: 25302952 DOI: 10.2217/fmb.14.61] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Foodborne pathogens pose serious public health risks. Rapid, accurate technologies to detect a low number of target cells (1 cell/25-325 g sample) and microbial toxins are in demand in order to assess product safety in hours to up to 1 day. Varied pathogen loads and the complexity of food present a major challenge. Current culture methods, while accurate, are lengthy. New methods, using brief culturing and detection kits (antibody based, nucleic acid amplification or nano/biosensors) or a culture-independent approach coupled with nucleic acid amplification, traditionally used for viruses/parasites, can be used to obtain results in hours. A strategic approach involving two-step, rapid, high-throughput screening to rule out negatives followed by a confirmatory test could accomplish product testing in 1 h to 1 day.
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18
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Molecular and nonmolecular diagnostic methods for invasive fungal infections. Clin Microbiol Rev 2015; 27:490-526. [PMID: 24982319 DOI: 10.1128/cmr.00091-13] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.
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20
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Ashrafi M, Nabili M, Shokohi T, Janbabaie G, Hedayati MT, Ali-Moghaddam K. A real time PCR assay on blood for diagnosis of invasive candidiasis in immunocompromised patient. Curr Med Mycol 2015; 1:35-41. [PMID: 28680979 PMCID: PMC5490320 DOI: 10.18869/acadpub.cmm.1.1.35] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background and Purpose: Invasive candidiasis (IC) is a significant cause of morbidity and mortality in patients with hematologic disorders and bone marrow transplant recipients. Rapid, specific and sensitive test for the timely accuracy in immunocompromised patients to reduce mortality rates and prevent IC progress is necessary. We established a real-time PCR assay on blood for the diagnosis and differentiation of the causative Candida species. Materials and Methods: Whole blood samples were collected twice, from 72 patients for Real Time PCR and blood culture assays. The primers and hybridization probes were designed to potentiate the specific sequence of 18S rRNA genes using Light Cycler system and Fluorescence Resonance Energy Transfer (FERT). The patients with hematologic malignancies and bone marrow transplant recipients were evaluated for IC based on the revised European Organization for Research and Treatment of Cancer/ Mycoses Study Group (EORTC/MSG) criteria. Results: From 2009 to 2011, 72 patients with hematologic malignancies and bone marrow transplant recipients were evaluated for IC. The female to male ratio was 27:45; the mean age was 32.1 years. The most common malignancy in this patient was acute myeloid leukemia (AML) (27.8%) and acute lymphoblastic leukemia (ALL) (26.4%). Out of 72 patients, 11 patients (15.3%) had positive real time PCR /probe results. Based on the melting temperature (Tm) analysis, 5 (45.4%) C. krusei, 3 (27.2%) C. tropicalis, 2 (18.1%) C. parapsilosis and 1 C. albicans (9%) were identified. According to the revised EORTC / MSG, 1 patient (9%) and 10 patients (91%) were defined as proven and possible groups of IC, respectively. The mortality rate in proven and possible IC patient was found 54.5%. Conclusion: The established Real-time PCR/FRET probe assay is an appropriate diagnostic tool for the detection of Candida species DNA and the management of patients suffering from hematologic malignancies and bone marrow recipient are at risk for IC
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Affiliation(s)
- M Ashrafi
- Student research committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - M Nabili
- Student research committee, Mazandaran University of Medical Sciences, Sari, Iran.,Social Security Organization, Golestan, Iran
| | - T Shokohi
- Invasive Fungi Research Center (IFRC), and Department of Medical Parasitology and Mycology, Mazandaran University of Medical Sciences, Sari, Iran
| | - G Janbabaie
- Department of Internal Medicine, Cell and Molecular Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - M T Hedayati
- Invasive Fungi Research Center (IFRC), and Department of Medical Parasitology and Mycology, Mazandaran University of Medical Sciences, Sari, Iran
| | - K Ali-Moghaddam
- Hematology-Oncology Research Center and Stem Cell Transplantation Research Center (HORCSCT), Tehran University of Medical Sciences, Iran
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Epidemiology of Invasive Candidiasis and Challenges for the Mycology Laboratory: Specificities of Candida glabrata. CURRENT CLINICAL MICROBIOLOGY REPORTS 2014. [DOI: 10.1007/s40588-014-0002-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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PCR in diagnosis of invasive aspergillosis: a meta-analysis of diagnostic performance. J Clin Microbiol 2014; 52:3731-42. [PMID: 25122854 DOI: 10.1128/jcm.01365-14] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Invasive aspergillosis is a difficult-to-diagnose infection with a high mortality rate that affects high-risk groups such as patients with neutropenia and hematologic malignancies. We performed a bivariate meta-analysis of diagnostic data for an Aspergillus sp. PCR assay with blood specimens from high-risk hematology patients. We included all studies involving human subjects that assessed the performance of any PCR assay for invasive aspergillosis in whole blood or serum and that used the European Organization for the treatment of Cancer/Mycoses Study Group criteria as a reference standard. Three investigators independently searched the literature for eligible studies and extracted the data. Out of a total of 37 studies, 25 met strict quality criteria and were included in our evidence synthesis. Twenty-five studies with 2,595 patients were analyzed. The pooled diagnostic performance of whole-blood and serum PCR assays was moderate, with a sensitivity and specificity of 84% (95% confidence interval [CI], 75 to 91%) and 76% (95% CI, 65 to 84%), respectively, suggesting that a positive or negative result is unable, on its own, to confirm or exclude a suspected infection. The performance of a PCR assay of serum was not significantly different from that of whole blood. Notably, at least two positive PCR test results were found to have a specificity of 95% and a sensitivity of 64% for invasive infection, achieving a high positive likelihood ratio of 12.8. Importantly, the European Aspergillus PCR Initiative (EAPCRI) recommendations improved the performance of the PCR even further when at least two positive specimens were used to define PCR positivity. In conclusion, two positive PCR results should be considered highly indicative of an active Aspergillus sp. infection. Use of the EAPCRI recommendations by clinical laboratories can further enhance PCR performance.
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Chumpitazi BFF, Lebeau B, Faure-Cognet O, Hamidfar-Roy R, Timsit JF, Pavese P, Thiebaut-Bertrand A, Quesada JL, Pelloux H, Pinel C. Characteristic and clinical relevance of Candida mannan test in the diagnosis of probable invasive candidiasis. Med Mycol 2014; 52:462-71. [DOI: 10.1093/mmy/myu018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Dimopoulos G, Antonopoulou A, Armaganidis A, Vincent JL. How to select an antifungal agent in critically ill patients. J Crit Care 2014; 28:717-27. [PMID: 24018296 DOI: 10.1016/j.jcrc.2013.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 04/11/2013] [Accepted: 04/13/2013] [Indexed: 12/29/2022]
Abstract
Fungal infections are common in critically ill patients and are associated with increased morbidity and mortality. Candida spp are the most commonly isolated fungal pathogens. The last 2 decades have seen an increased incidence of fungal infections in critical illness and the emergence of new pathogenic fungal species and also the development of more effective (better bioavailability) and safer (less toxicity, fewer drug interactions) drugs. The distinction between colonization and infection can be difficult, and problems diagnosing infection may delay initiation of antifungal treatment. A number of factors have been identified that can help to distinguish patients at high risk for fungal infection. The antifungal agents that are most frequently used in the intensive care unit are the first- and second-generation azoles and the echinocandins; amphotericin B derivatives (mainly the liposomal agents) are less widely used because of adverse effects. The choice of antifungal agent in critically ill patients will depend on the aim of therapy (prophylaxis, pre-emptive, empiric, definitive), as well as on local epidemiology and specific properties of the drug (antifungal spectrum, efficacy, toxicity, pharmacokinetic/pharmacodynamic properties, cost). In this article we will review all these aspects and propose an algorithm to guide selection of antifungal agents in critically ill patients.
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Affiliation(s)
- George Dimopoulos
- 2nd Department of Critical Care Medicine, Medical School, University of Athens, University Hospital ATTIKON, Athens, Greece
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Fungal DNA detected in blood samples of patients who received contaminated methylprednisolone injections reveals increased complexity of causative agents. J Clin Microbiol 2014; 52:2212-5. [PMID: 24719442 DOI: 10.1128/jcm.00854-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using Exserohilum rostratum-specific and panfungal real-time PCR, we studied 24 blood samples and 2 synovial fluid specimens from 20 patients with persistent or worsening pain following injections of contaminated methylprednisolone. Seven blood specimens from 6 patients were significantly positive for fungal DNA by panfungal PCR, with multiple fungal species identified.
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Romero R, Miranda J, Chaiworapongsa T, Chaemsaithong P, Gotsch F, Dong Z, Ahmed AI, Yoon BH, Hassan SS, Kim CJ, Korzeniewski SJ, Yeo L. A novel molecular microbiologic technique for the rapid diagnosis of microbial invasion of the amniotic cavity and intra-amniotic infection in preterm labor with intact membranes. Am J Reprod Immunol 2014; 71:330-58. [PMID: 24417618 DOI: 10.1111/aji.12189] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 11/25/2013] [Indexed: 12/16/2022] Open
Abstract
PROBLEM The diagnosis of microbial invasion of the amniotic cavity (MIAC) has been traditionally performed using traditional cultivation techniques, which require growth of microorganisms in the laboratory. Shortcomings of culture methods include the time required (days) for identification of microorganisms, and that many microbes involved in the genesis of human diseases are difficult to culture. A novel technique combines broad-range real-time polymerase chain reaction with electrospray ionization time-of-flight mass spectrometry (PCR/ESI-MS) to identify and quantify genomic material from bacteria and viruses. METHOD OF STUDY AF samples obtained by transabdominal amniocentesis from 142 women with preterm labor and intact membranes (PTL) were analyzed using cultivation techniques (aerobic, anaerobic, and genital mycoplasmas) as well as PCR/ESI-MS. The prevalence and relative magnitude of intra-amniotic inflammation [AF interleukin 6 (IL-6) concentration ≥ 2.6 ng/mL], acute histologic chorioamnionitis, spontaneous preterm delivery, and perinatal mortality were examined. RESULTS (i) The prevalence of MIAC in patients with PTL was 7% using standard cultivation techniques and 12% using PCR/ESI-MS; (ii) seven of ten patients with positive AF culture also had positive PCR/ESI-MS [≥17 genome equivalents per PCR reaction well (GE/well)]; (iii) patients with positive PCR/ESI-MS (≥17 GE/well) and negative AF cultures had significantly higher rates of intra-amniotic inflammation and acute histologic chorioamnionitis, a shorter interval to delivery [median (interquartile range-IQR)], and offspring at higher risk of perinatal mortality, than women with both tests negative [90% (9/10) versus 32% (39/122) OR: 5.6; 95% CI: 1.4-22; (P < 0.001); 70% (7/10) versus 35% (39/112); (P = 0.04); 1 (IQR: <1-2) days versus 25 (IQR: 5-51) days; (P = 0.002), respectively]; (iv) there were no significant differences in these outcomes between patients with positive PCR/ESI-MS (≥17 GE/well) who had negative AF cultures and those with positive AF cultures; and (v) PCR/ESI-MS detected genomic material from viruses in two patients (1.4%). CONCLUSION (i) Rapid diagnosis of intra-amniotic infection is possible using PCR/ESI-MS; (ii) the combined use of biomarkers of inflammation and PCR/ESI-MS allows for the identification of specific bacteria and viruses in women with preterm labor and intra-amniotic infection; and (iii) this approach may allow for administration of timely and specific interventions to reduce morbidity attributed to infection-induced preterm birth.
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Affiliation(s)
- Roberto Romero
- Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA, and Detroit, MI, USA; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
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Laín A, Elguezabal N, Moragues MD, García-Ruiz JC, del Palacio A, Pontón J. Contribution of serum biomarkers to the diagnosis of invasive candidiasis. Expert Rev Mol Diagn 2014; 8:315-25. [DOI: 10.1586/14737159.8.3.315] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Invasive candidiasis serological diagnosis in solid organ transplant recipients. Cent Eur J Immunol 2014; 39:187-92. [PMID: 26155122 PMCID: PMC4440018 DOI: 10.5114/ceji.2014.43721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 04/29/2014] [Indexed: 11/23/2022] Open
Abstract
Solid organ transplant recipients are at high risk of fungal infections, because of ongoing immunosuppressive treatment. There are three post organ transplant phases: early, intermediate, and late, all of them at risk of Candida infections. Since conventional tests are insufficient, specific secondary diagnostic tests are still being explored. Serological tests are currently the most common choice. The present study was to determine the usefulness of mannan antigen and anti-mannan antibody detection in diagnosing invasive candidiasis in liver or kidney transplant recipients. The levels of mannan and anti-mannan antibodies were assessed with Platelia Candida Ag Plus, and Platelia Candida Ab Plus (Biorad, Marne-la-Coquette, France) commercial tests, according to manufacturer's guidelines. Sixty six serum samples were obtained from 25 patients (9 liver transplant recipients, 7 kidney transplant recipients, and 9 patients prepared for a kidney transplant), 29 serum samples from 15 patients tested positive for mannan antigen. Serum samples were obtained from 14 patients tested positive for anti- mannan antibodies. Fungal antigen detection in blood serum in patients under immunosuppression, especially with neutropenia, suggests that antifungal treatment should be administered. Serological tests, especially mannan and anti-mannan ones, are very useful for confirmation or exclusion of invasive candidiasis in high-risk patients.
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Maly J, Szarszoi O, Netuka I, Dorazilova Z, Pirk J. Fungal infections associated with long-term mechanical circulatory support-diagnosis and management. J Card Surg 2013; 29:95-100. [PMID: 24279890 DOI: 10.1111/jocs.12258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Left ventricular assist devices (LVADs) are increasingly used as a treatment option for advanced heart failure. Fungal infections present a serious concern given the high association with major adverse events including death in this group of patients. The objective of this review is to summarize the incidence, risk factors, method for diagnosis, complication rate, and outcomes in patients with VADs who develop fungal infections.
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Affiliation(s)
- Jiri Maly
- Department of Cardiovascular Surgery, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Department of Cardiovascular Surgery, Second Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
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Barnes RA, Stocking K, Bowden S, Poynton MH, White PL. Prevention and diagnosis of invasive fungal disease in high-risk patients within an integrative care pathway. J Infect 2013; 67:206-14. [DOI: 10.1016/j.jinf.2013.04.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/06/2013] [Accepted: 04/26/2013] [Indexed: 10/26/2022]
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New strategy for rapid diagnosis and characterization of fungal infections: the example of corneal scrapings. PLoS One 2012; 7:e37660. [PMID: 22768289 PMCID: PMC3388096 DOI: 10.1371/journal.pone.0037660] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Purpose The prognosis of people infected with Fungi especially immunocompromised depends on rapid and accurate diagnosis to capitalize on time administration of specific treatments. However, cultures produce false negative results and nucleic-acid amplification techniques require complex post-amplification procedures to differentiate relevant fungal types. The objective of this work was to develop a new diagnostic strategy based on real-time polymerase-chain reaction high-resolution melting analysis (PCR-HRM) that a) detects yeasts and filamentous Fungi, b) differentiates yeasts from filamentous Fungi, and c) discriminates among relevant species of yeasts. Methods PCR-HRM detection limits and specificity were assessed with a) isolated strains; b) human blood samples experimentally infected with Fungi; c) blood experimentally infected with other infectious agents; d) corneal scrapings from patients with suspected fungal keratitis (culture positive and negative) and e) scrapings from patients with suspected bacterial, viral or Acanthamoeba infections. The DNAs were extracted and mixed with primers diluted in the MeltDoctor® HRM Master Mix in 2 tubes, the first for yeasts, containing the forward primer CandUn (5'CATGCCTGTTTGAGCGTC) and the reverse primer FungUn (5'TCCTCCGCTT ATTGATATGCT) and the second for filamentous Fungi, containing the forward primer FilamUn (5'TGCCTGTCCGAGCGTCAT) and FungUn. Molecular probes were not necessary. The yields of DNA extraction and the PCR inhibitors were systematically monitored. Results PCR-HRM detected 0.1 Colony Forming Units (CFU)/µl of yeasts and filamentous Fungi, differentiated filamentous Fungi from yeasts and discriminated among relevant species of yeasts. PCR-HRM performances were higher than haemoculture and sensitivity and specificity was 100% for culture positive samples, detecting and characterizing Fungi in 7 out 10 culture negative suspected fungal keratitis. Conclusions PCR-HRM appears as a new, sensitive, specific and inexpensive test that detects Fungi and differentiates filamentous Fungi from yeasts. It allows direct fungal detection from clinical samples and experimentally infected blood in less than 2.30 h after DNA extraction.
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Kourkoumpetis TK, Fuchs BB, Coleman JJ, Desalermos A, Mylonakis E. Polymerase chain reaction-based assays for the diagnosis of invasive fungal infections. Clin Infect Dis 2012; 54:1322-31. [PMID: 22362884 DOI: 10.1093/cid/cis132] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Currently accepted fungal diagnostic techniques, such as culture, biopsy, and serology, lack rapidity and efficiency. Newer diagnostic methods, such as polymerase chain reaction (PCR)-based assays, have the potential to improve fungal diagnostics in a faster, more sensitive, and specific manner. Preliminary data indicate that, when PCR-based fungal diagnostic assays guide antifungal therapy, they may lower patient mortality and decrease unnecessary antifungal treatment, improving treatment-associated costs and avoiding toxicity. Moreover, newer PCR techniques can identify antifungal resistance DNA loci, but the clinical correlation between those loci and clinical failure has to be studied further. In addition, future studies need to focus on the implementation of PCR techniques in clinical decision making and on combining them with other diagnostic tests. A consensus on the standardization of PCR techniques, along with validation from large prospective studies, is necessary to allow widespread adoption of these assays.
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Affiliation(s)
- Themistoklis K Kourkoumpetis
- Department of Medicine, Infectious Disease Division, Massachusetts General Hospital, Harvard Medical School, Boston 02214, USA
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Goldschmidt P, Degorge S, Benallaoua D, Semoun O, Borsali E, Le Bouter A, Batellier L, Borderie V, Laroche L, Chaumeil C. New strategy for rapid diagnosis and characterization of keratomycosis. Ophthalmology 2012; 119:945-50. [PMID: 22342013 DOI: 10.1016/j.ophtha.2011.10.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 10/31/2011] [Accepted: 10/31/2011] [Indexed: 10/28/2022] Open
Abstract
PURPOSE The first-line therapy for patients with keratitis is different for bacteria, filamentous fungi, and yeasts. The timely onset of treatments depends on rapid and accurate diagnosis. However, fungal cultures produce high rates of false-negative results. Nucleic acid amplification techniques (polymerase chain reaction [PCR]) improve fungal diagnosis performance, but they require complex postamplification procedures to differentiate filamentous fungi from yeasts or to identify the agent. The objective of this work was to develop a new diagnostic strategy based on real-time PCR high-resolution melting (HRM) analysis that in 1 run (a) detects and semiquantifies yeasts and filamentous fungi, (b) differentiates yeasts from filamentous fungi, and (c) discriminates among relevant species of yeasts. DESIGN Experimental study to compare HRM diagnosis performances with microscopic examination of corneal scrapings and fungal culture. PARTICIPANTS AND CONTROLS High-resolution melting detection limits and specificity were assessed with (a) isolated strains; (b) agents (other than fungi) producing keratitis; (c) corneal scrapings from fungal keratitis (culture positive and negative); and (d) corneal scrapings from bacterial, viral, or Acanthamoeba keratitis. METHODS The DNA extracted from cornea specimens was mixed with primers diluted in the MeltDoctor HRM Master Mix (Applied Biosystems, Paris, France) in 2 tubes, the first for yeasts, containing the forward primer CandUn (5'CATGCCTGTTTGAGCGTC) and the reverse primer FungUn2 (5'TCCTCCGCTTATTGATATGCT), and the second for filamentous fungi, containing the forward primer FilamUn1 (5'TGCCTGTCCGAGCGTCAT) and FungUn2. Molecular probes were not necessary. The yields of DNA extraction and the PCR inhibitors were monitored by adding internal controls to each sample. MAIN OUTCOME MEASURES Detection of fungi in corneal samples by HRM. RESULTS High-resolution melting consistently detects the equivalent of 0.1 colony-forming units /ml of yeasts and filamentous fungi, differentiates filamentous fungi from yeasts, and discriminates among relevant species of yeasts. High-resolution melting sensitivity and specificity were 100% for culture-positive samples, detecting and characterizing fungi in 7 of 10 culture-negative suspected fungal keratitis. CONCLUSIONS High-resolution melting is a new, sensitive, specific, and inexpensive test that detects fungi and differentiates filamentous fungi from yeasts directly from clinical specimens in less than 2.30 hours after DNA extraction.
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Affiliation(s)
- Pablo Goldschmidt
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France.
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Slechta ES, Hohmann SL, Simmon K, Hanson KE. Internal transcribed spacer region sequence analysis using SmartGene IDNS software for the identification of unusual clinical yeast isolates. Med Mycol 2011; 50:458-66. [PMID: 22103344 DOI: 10.3109/13693786.2011.630683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rapid and accurate identification of clinically important yeasts is essential given their inherent differences in antifungal susceptibility. We implemented nucleic acid sequencing for those species that could not be identified by phenotypic methods. Internal Transcribed Spacer region 1 and 2 (ITS1 and ITS2) sequences were investigated using SmartGene IDNS software, an rDNA sequence database and analysis program for microbial identification (ID). Over a 2.5-year period, 2,938 specimens were evaluated. Most (94%) isolates were fully identified by conventional methods, with Candida species accounting for the majority of them. Of the 169 organisms that required molecular analysis, 79% were identified to species level, 19% to genus and 2% remained unresolved. Sequenced isolates encompassed 33 unique species of which approximately half (52%) were common pathogens with atypical biochemical profiles and the remainder were rarer yeast species. A significant proportion (33%) of sequenced organisms displayed elevated MICs to fluconazole. Our experience supports the use of molecular techniques as an adjunct to conventional methods for the identification of medically important yeasts. Susceptibility testing alone may provide valuable treatment information in situations where phenotypic assessments are inconclusive and molecular or proteomic testing is not readily available.
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Affiliation(s)
- E Susan Slechta
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, USA
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Ruhnke M, Rickerts V, Cornely OA, Buchheidt D, Glöckner A, Heinz W, Höhl R, Horré R, Karthaus M, Kujath P, Willinger B, Presterl E, Rath P, Ritter J, Glasmacher A, Lass-Flörl C, Groll AH. Diagnosis and therapy of Candida infections: joint recommendations of the German Speaking Mycological Society and the Paul-Ehrlich-Society for Chemotherapy. Mycoses 2011; 54:279-310. [PMID: 21672038 DOI: 10.1111/j.1439-0507.2011.02040.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Invasive Candida infections are important causes of morbidity and mortality in immunocompromised and hospitalised patients. This article provides the joint recommendations of the German-speaking Mycological Society (Deutschsprachige Mykologische Gesellschaft, DMyKG) and the Paul-Ehrlich-Society for Chemotherapy (PEG) for diagnosis and treatment of invasive and superficial Candida infections. The recommendations are based on published results of clinical trials, case-series and expert opinion using the evidence criteria set forth by the Infectious Diseases Society of America (IDSA). Key recommendations are summarised here: The cornerstone of diagnosis remains the detection of the organism by culture with identification of the isolate at the species level; in vitro susceptibility testing is mandatory for invasive isolates. Options for initial therapy of candidaemia and other invasive Candida infections in non-granulocytopenic patients include fluconazole or one of the three approved echinocandin compounds; liposomal amphotericin B and voriconazole are secondary alternatives because of their less favourable pharmacological properties. In granulocytopenic patients, an echinocandin or liposomal amphotericin B is recommended as initial therapy based on the fungicidal mode of action. Indwelling central venous catheters serve as a main source of infection independent of the pathogenesis of candidaemia in the individual patients and should be removed whenever feasible. Pre-existing immunosuppressive treatment, particularly by glucocorticosteroids, ought to be discontinued, if feasible, or reduced. The duration of treatment for uncomplicated candidaemia is 14 days following the first negative blood culture and resolution of all associated symptoms and findings. Ophthalmoscopy is recommended prior to the discontinuation of antifungal chemotherapy to rule out endophthalmitis or chorioretinitis. Beyond these key recommendations, this article provides detailed recommendations for specific disease entities, for antifungal treatment in paediatric patients as well as a comprehensive discussion of epidemiology, clinical presentation and emerging diagnostic options of invasive and superficial Candida infections.
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Affiliation(s)
- Markus Ruhnke
- Medizinische Klinik m S Onkologie u Hämatologie, Charité Universitätsmedizin, Charité, Campus Mitte, Berlin, Germany.
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ECIL recommendations for the use of biological markers for the diagnosis of invasive fungal diseases in leukemic patients and hematopoietic SCT recipients. Bone Marrow Transplant 2011; 47:846-54. [DOI: 10.1038/bmt.2011.178] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Update on the laboratory diagnosis of invasive fungal infections. Mediterr J Hematol Infect Dis 2011; 3:e2011002. [PMID: 21625306 PMCID: PMC3103235 DOI: 10.4084/mjhid.2011.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 12/31/2010] [Indexed: 11/22/2022] Open
Abstract
Recent advances in the management of patients with haematological malignancies and transplant recipients have paralleled an increase in the incidence of fungal diseases due to pathogenic genera such as Candida and Aspergillus and the emergence of less common genera including Fusarium and Zygomycetes. Despite availability of new antifungal agents these opportunistic infections have high mortality. Rapid and reliable species identification is essential for antifungal treatment, but detection of the increasing diversity of fungal pathogens by conventional phenotypic methods remains difficult and time-consuming, and the results may sometimes be inconclusive, especially for unusual species. New diagnostic techniques (e.g., 1,3-beta-d-glucan detection) could improve this scenario, although further studies are necessary to confirm their usefulness in clinical practice.
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Comparación entre métodos convencionales, ChromAgar Candida® y el método de la PCR para la identificación de especies de Candida en aislamientos clínicos. Rev Iberoam Micol 2011; 28:36-42. [DOI: 10.1016/j.riam.2010.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 11/09/2010] [Accepted: 11/18/2010] [Indexed: 11/19/2022] Open
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Mikulska M, Calandra T, Sanguinetti M, Poulain D, Viscoli C. The use of mannan antigen and anti-mannan antibodies in the diagnosis of invasive candidiasis: recommendations from the Third European Conference on Infections in Leukemia. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R222. [PMID: 21143834 PMCID: PMC3219989 DOI: 10.1186/cc9365] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/02/2010] [Accepted: 12/08/2010] [Indexed: 12/16/2022]
Abstract
Introduction Timely diagnosis of invasive candidiasis (IC) remains difficult as the clinical presentation is not specific and blood cultures lack sensitivity and need a long incubation time. Thus, non-culture-based methods for diagnosing IC have been developed. Mannan antigen (Mn) and anti-mannan antibodies (A-Mn) are present in patients with IC. On behalf of the Third European Conference on Infections in Leukemia, the performance of these tests was analysed and reviewed. Methods The literature was searched for studies using the commercially available sandwich enzyme-linked immunosorbent assays (Platelia™, Bio-Rad Laboratories, Marnes-la-Coquette, France) for detecting Mn and A-Mn in serum. The target condition of this review was IC defined according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity, specificity and diagnostic odds ratios (DOR) were calculated for Mn, A-Mn and combined Mn/A-Mn testing. Results Overall, 14 studies that comprised 453 patients and 767 controls were reviewed. The patient populations included in the studies were mainly haematological and cancer cases in seven studies and mainly intensive care unit and surgery cases in the other seven studies. All studies but one were retrospective in design. Mn sensitivity was 58% (95% confidence interval [CI], 53-62); specificity, 93% (95% CI, 91-94) and DOR, 18 (95% CI 12-28). A-Mn sensitivity was 59% (95% CI, 54-65); specificity, 83% (95% CI, 79-97) and DOR, 12 (95% CI 7-21). Combined Mn/A-Mn sensitivity was 83% (95% CI, 79-87); specificity, 86% (95% CI, 82-90) and DOR, 58 (95% CI 27-122). Significant heterogeneity of the studies was detected. The sensitivity of both Mn and A-Mn varied for different Candida species, and it was the highest for C. albicans, followed by C. glabrata and C. tropicalis. In 73% of 45 patients with candidemia, at least one of the serological tests was positive before the culture results, with mean time advantage being 6 days for Mn and 7 days for A-Mn. In 21 patients with hepatosplenic IC, 18 (86%) had Mn or A-Mn positive test results at a median of 16 days before radiological detection of liver or spleen lesions. Conclusions Mn and A-Mn are useful for diagnosis of IC. The performance of combined Mn/A-Mn testing is superior to either Mn or A-Mn testing.
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Affiliation(s)
- Malgorzata Mikulska
- Division of Infectious Diseases, San Martino University Hospital, L,go R, Benzi, 10, Genoa, Italy.
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PCR diagnosis of invasive candidiasis: systematic review and meta-analysis. J Clin Microbiol 2010; 49:665-70. [PMID: 21106797 DOI: 10.1128/jcm.01602-10] [Citation(s) in RCA: 267] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Invasive candidiasis (IC) is a significant cause of morbidity and mortality. Diagnosis relies on culture-based methods, which lack sensitivity and delay diagnosis. We conducted a systematic review assessing the diagnostic accuracy of PCR-based methods to detect Candida spp. directly in blood samples. We searched electronic databases for prospective or retrospective cohort and case-control studies. Two reviewers abstracted data independently. Meta-analysis was performed using a hierarchical logistic regression model. Random-effects metaregression was performed to assess the effects of study methods and infection characteristics on sensitivity or specificity values. We included 54 studies with 4,694 patients, 963 of whom had proven/probable or possible IC. Perfect (100%) sensitivity and specificity for PCR in whole-blood samples was observed when patients with cases had candidemia and controls were healthy people. When PCR was performed to evaluate patients with suspected invasive candidiasis, the pooled sensitivity for the diagnosis of candidemia was 0.95 (confidence interval, 0.88 to 0.98) and the pooled specificity was 0.92 (0.88 to 0.95). A specificity of >90% was maintained in several analyses considering different control groups. The use of whole-blood samples, rRNA, or P450 gene targets and a PCR detection limit of ≤ 10 CFU/ml were associated with improved test performance. PCR positivity rates among patients with proven or probable IC were 85% (78 to 91%), while blood cultures were positive for 38% (29 to 46%). We conclude that direct PCR using blood samples had good sensitivity and specificity for the diagnosis of IC and offers an attractive method for early diagnosis of specific Candida spp. Its effects on clinical outcomes should be investigated.
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Fricke S, Fricke C, Schimmelpfennig C, Oelkrug C, Schönfelder U, Blatz R, Zilch C, Faber S, Hilger N, Ruhnke M, Rodloff AC. A real-time PCR assay for the differentiation of Candida species. J Appl Microbiol 2010; 109:1150-8. [PMID: 20456528 DOI: 10.1111/j.1365-2672.2010.04736.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
AIMS We established a real-time PCR assay for the detection and strain identification of Candida species and demonstrated the ability to differentiate between Candida albicans the most common species, and also Candida parapsilosis, Candida glabrata, Candida tropicalis and Candida dubliniensis by LightCycler PCR and melting curve analysis. METHODS AND RESULTS The DNA isolation from cultures and serum was established using the QIAmp Tissue Kit. The sensitivity of the assay was ≥ 2 genome equivalents/assay. It was possible to differentiate all investigated Candida species by melting curve analysis, and no cross-reaction to human DNA or Aspergillus species could be observed. CONCLUSIONS The established real-time PCR assay is a useful tool for the rapid identification of Candida species and a base technology for more complex PCR assays. SIGNIFICANCE AND IMPACT OF THE STUDY We carried out initial steps in validation of a PCR assay for the detection and differentiation of medically relevant Candida species. The PCR was improved by generating PCR standards, additional generation of melting curves for species identification and the possibility to investigate different specimens simultaneously.
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Affiliation(s)
- S Fricke
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Leipzig, Germany.
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Arendrup M, Bergmann O, Larsson L, Nielsen H, Jarløv J, Christensson B. Detection of candidaemia in patients with and without underlying haematological disease. Clin Microbiol Infect 2010; 16:855-62. [DOI: 10.1111/j.1469-0691.2009.02931.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Khot PD, Fredricks DN. PCR-based diagnosis of human fungal infections. Expert Rev Anti Infect Ther 2010; 7:1201-21. [PMID: 19968513 DOI: 10.1586/eri.09.104] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PCR is a very appealing technology for the detection of human pathogens, but the detection of fungal pathogens is particularly challenging. Fungi have cell walls that impede the efficient lysis of organisms and liberation of DNA, which can lead to false-negative PCR results. Conversely, some human pathogens are also ubiquitous environmental saprophytes that can contaminate PCR reagents and cause false-positive results. We examine the quality of PCR-based studies for fungal diagnostics using 42 variables within the Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines. This review focuses on taxon-directed PCR assays for the diagnosis of invasive aspergillosis, candidiasis and Pneumocystis pneumonia. Finally, we evaluate broad-range fungal PCR assays capable of detecting a wide spectrum of human pathogens.
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Affiliation(s)
- Prasanna D Khot
- Vaccine and Infectious Disease Institute, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109-1024, USA.
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Goyal NK, Gore MA, Goyal RS. Fungal colonisation in burn wounds: An Indian scenerio. Indian J Surg 2010; 72:49-52. [PMID: 23133204 DOI: 10.1007/s12262-010-0009-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2009] [Accepted: 05/18/2009] [Indexed: 11/28/2022] Open
Abstract
UNLABELLED Burn patients are susceptible hosts for fungal colonisation. AIM To study incidence and profile of fungal colonisation of burn wounds. MATERIALS AND METHODS This prospective study was conducted in 201 consecutive adult patients (39 male and 162 female) with burn wounds, admitted from October 2005 to September 2006. Wounds with clinical suspicion of fungal colonisation were biopsied and examined by wet smear, Potassium hydroxide (KOH) mount, nigrosin stain, 1% Acid fast bacilli (AFB) stain, Gomori methenamine silver (GMS) stain, histopathological examination and fungal culture. All wounds with suspicion of fungal colonisation were treated with topical application of miconazole ointment mixed with povidone-iodine/silver sulphadiazine topically and itraconazole (oral) systemically. RESULTS Fungal infection of burn wound was suspected in 77 patients (38.31%) with 20-70% total body surface area (TBSA) burns. Ninety-two biopsy samples were collected from 77 patients. On investigations, fungal colonisation was confirmed in 35 patients. Culture was positive in 23 patients with Candida in 12 and Aspergillus in 4. GMS stain and KOH stain showed sensitivity and specificity of 70.8% and 86.5%, respectively for detecting fungi in burn wound. Nigrosin stain was negative in all patients. Duration of hospitalisation was more in patients having fungal colonisation without any significant effect on the mortality DISCUSSION In 38.31% of patients fungal colonisation was clinically suspected and it was confirmed in 17.41% of 201 patients. GMS stain and KOH stain were observed to have acceptable sensitivity and specificity. With increasing prevalence of Aspergillus, flucanazole cannot be relied upon in controlling fungal colonisation and drugs like itraconazole may have to be used as empirical therapy. CONCLUSION Fungal colonisation of burn wound is not uncommon and should be suspected. Fungi detected most commonly were Candida and Aspergillus. KOH and GMS stain were identified as reliable, simple and inexpensive methods for confirming fungal colonisation.
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Affiliation(s)
- Navin Kumar Goyal
- Department of Surgery, LTM Medical College, Sion, Mumbai, Maharashtra India
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Pagano L, Caira M, Valentini CG, Posteraro B, Fianchi L. Current therapeutic approaches to fungal infections in immunocompromised hematological patients. Blood Rev 2010; 24:51-61. [PMID: 20056300 DOI: 10.1016/j.blre.2009.11.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Invasive fungal infections are significant causes of morbidity and mortality in patients with hematological malignancies. Patients with acute myeloid leukemia and those who have undergone allogeneic hematopoietic stem cell transplantation are at especially high risk. Various fungal agents are responsible for this complication, but Aspergillus spp. and Candida spp. are the most frequently isolated micro-organisms; less commonly, infections could be caused by Zygomycetes or other rare molds or yeasts. Several new systemically-administered antifungal agents have been approved for clinical use since 2001; these agents include liposomal amphotericin B, voriconazole, caspofungin, and posaconazole, and they represent a major advance in antifungal therapy and have improved the prognosis of patients with hematological malignancies. This review focuses on therapeutic aspects of the management of fungal infections in hematological patients.
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Affiliation(s)
- Livio Pagano
- Istituto di Ematologia, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, Rome, Italy.
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Prospective monitoring for invasive aspergillosis using galactomannan and polymerase chain reaction in high risk pediatric patients. J Pediatr Hematol Oncol 2009; 31:920-6. [PMID: 19855303 DOI: 10.1097/mph.0b013e3181b83e77] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND The diagnosis of invasive aspergillus remains a challenge in the care of high-risk patients. Outcomes are improved when invasive aspergillus is diagnosed early, prompting the initiation of appropriate antifungal therapy. We evaluated the utility of prospective monitoring for invasive aspergillosis (IA) using biomarkers such as serum galactomannan (GM) and/or blood polymerase chain reaction (PCR) in high-risk pediatric patients. METHODS Patients with high-risk leukemia (HRL) or allogenic hematopoietic cell transplant (HCT) recipients were prospectively monitored twice weekly for IA using GM and PCR for Aspergillus species. RESULTS Sixty-eight patients had collected >or=2 specimens. The 1086 specimens were collected; 627 from HRL (58%) and 459 (42%) from HCT recipients. Median specimens/patient was 11.0 (2 to 58), and median follow-up/patient was 98.5 days (14 to 437). Fifty-six percent of samples were obtained from patients receiving mold-active agents; 32% HRL and 89% HCT. There were no proven, 3 probable, and 20 possible episodes of IA. Thirteen specimens (1.2%) from 4 patients (5%) were GM+. None were positive by PCR. CONCLUSIONS The prospective use of GM and PCR in this high-risk pediatric population did not identify cases of proven IA. A high false positive rate was not detected. It is speculated that changes in clinical practice, such as early use of empiric and/or prophylactic mold-active agent and frequent imaging studies have impacted the epidemiology of IA. In a population with low incidence of IA, the use of these assays as a screening device on blood may not further enhance current outcomes.
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Polymerase chain reaction diagnosis of fungal disease: Finally coming of age. CURRENT FUNGAL INFECTION REPORTS 2009. [DOI: 10.1007/s12281-009-0029-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lau A, Chen S, Sleiman S, Sorrell T. Current status and future perspectives on molecular and serological methods in diagnostic mycology. Future Microbiol 2009; 4:1185-222. [DOI: 10.2217/fmb.09.70] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex® xMAP™) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum β-D-glucan test have value for diagnosing infection and monitoring therapeutic response.
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Affiliation(s)
- Anna Lau
- Centre for Infectious Diseases & Microbiology, University of Sydney, Sydney, Australia
| | - Sharon Chen
- Centre for Infectious Diseases & Microbiology, University of Sydney, Sydney, Australia and Centre for Infectious Diseases & Microbiology Laboratory Services, Institute of Clinical Pathology & Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Sue Sleiman
- Centre for Infectious Diseases & Microbiology Laboratory Services, Institute of Clinical Pathology & Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Tania Sorrell
- Centre for Infectious Diseases & Microbiology, Westmead Hospital, Darcy and Hawkesbury Roads, Westmead, NSW 2145, Australia
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Abstract
Invasive fungal infections are important causes of morbidity and mortality in patients with bone marrow failure syndromes and hematological malignancies, or who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Current epidemiological trends indicate a shift toward infections by Aspergillus spp., non-albicans Candida spp., and previously uncommon fungal pathogens that have decreased susceptibility to the available antifungal agents. The last two decades have seen substantial improvements in the clinical, laboratory, and radiological diagnosis of these infections and the development of new antifungal compounds. Progress has been made in establishing disease definitions and paradigms for antifungal intervention and in the design and conduct of interventional clinical trials. Collectively, these advances have led to major but ongoing changes in the management of patients at risk of or being affected by invasive fungal infections. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in immunocompromised patients with hematological disorders and discusses novel approaches to antifungal chemotherapy and adjunctive treatments.
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Affiliation(s)
- Andreas H Groll
- Infectious Disease Research Program, Center for Bone Marrow Transplantation and Department of Pediatric Hematology/Oncology, University Children's Hospital Muenster, Muenster, Germany.
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