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Riebold D, Mahnkopf M, Wicht K, Zubiria-Barrera C, Heise J, Frank M, Misch D, Bauer T, Stocker H, Slevogt H. Axenic Long-Term Cultivation of Pneumocystis jirovecii. J Fungi (Basel) 2023; 9:903. [PMID: 37755011 PMCID: PMC10533121 DOI: 10.3390/jof9090903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/18/2023] [Accepted: 08/29/2023] [Indexed: 09/28/2023] Open
Abstract
Pneumocystis jirovecii, a fungus causing severe Pneumocystis pneumonia (PCP) in humans, has long been described as non-culturable. Only isolated short-term experiments with P. jirovecii and a small number of experiments involving animal-derived Pneumocystis species have been published to date. However, P. jirovecii culture conditions may differ significantly from those of animal-derived Pneumocystis, as there are major genotypic and phenotypic differences between them. Establishing a well-performing P. jirovecii cultivation is crucial to understanding PCP and its pathophysiological processes. The aim of this study, therefore, was to develop an axenic culture for Pneumocystis jirovecii. To identify promising approaches for cultivation, a literature survey encompassing animal-derived Pneumocystis cultures was carried out. The variables identified, such as incubation time, pH value, vitamins, amino acids, and other components, were trialed and adjusted to find the optimum conditions for P. jirovecii culture. This allowed us to develop a medium that produced a 42.6-fold increase in P. jirovecii qPCR copy numbers after a 48-day culture. Growth was confirmed microscopically by the increasing number and size of actively growing Pneumocystis clusters in the final medium, DMEM-O3. P. jirovecii doubling time was 8.9 days (range 6.9 to 13.6 days). In conclusion, we successfully cultivated P. jirovecii under optimized cell-free conditions in a 70-day long-term culture for the first time. However, further optimization of the culture conditions for this slow grower is indispensable.
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Affiliation(s)
- Diana Riebold
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marie Mahnkopf
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Kristina Wicht
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, B-9000 Gent, Belgium;
| | - Cristina Zubiria-Barrera
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
| | - Jan Heise
- Research Centre of Medical Technology and Biotechnology (FZMB), 99947 Bad Langensalza, Germany; (M.M.); (J.H.)
| | - Marcus Frank
- Medical Biology and Electron Microscopy Centre (EMZ), University Medicine Rostock, 18057 Rostock, Germany;
| | - Daniel Misch
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Torsten Bauer
- Lungenklinik Heckeshorn, Helios Klinikum Emil-von-Behring, 14165 Berlin, Germany; (D.M.); (T.B.)
| | - Hartmut Stocker
- Clinic for Infectiology, St. Joseph’s Hospital Berlin, 12101 Berlin, Germany;
| | - Hortense Slevogt
- Respiratory Infection Dynamics Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (C.Z.-B.); (H.S.)
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, German Center for Lung Research (DZL), BREATH, 30625 Hannover, Germany
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2
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Hauser PM, Almeida JMGCF, Richard S, Meier CS. Cell Fusion May Be Involved in the Homothallic Mating of Pneumocystis Species. mBio 2022; 13:e0085922. [PMID: 35726921 PMCID: PMC9426428 DOI: 10.1128/mbio.00859-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Pneumocystis species are obligate fungal biotrophs that colonize the lungs of mammals. They cause deadly pneumonia in immunocompromised hosts. The sexual phase seems obligate during their life cycle and essential for survival because it is believed to ensure proliferation and transmission between hosts. Here, we consider if the sexual phase is initiated by the fusion of two cells or by nucleus duplication in order to generate diploid cells that can undergo meiosis. The juxtaposition of the nucleus-associated organelles of pairs of cells with fused cytoplasmic membranes demonstrated that cell fusion can occur. Nevertheless, the frequency of cell fusion remains to be determined, and it cannot be excluded that both cell fusion and nucleus duplication are used to ensure the occurrence of the essential sexual phase. In vitro culturing of these fungi is a major milestone that could clarify the issue.
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Affiliation(s)
- Philippe M. Hauser
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Joao M. G. C. F. Almeida
- UCIBIO—REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Sophie Richard
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Caroline S. Meier
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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3
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Ruiz-Ruiz S, Ponce CA, Pesantes N, Bustamante R, Gatti G, San Martin V, Gutierrez M, Bórquez P, Vargas SL, Magne F, Calderón EJ, Pérez-Brocal V, Moya A. A Real-Time PCR Assay for Detection of Low Pneumocystis jirovecii Levels. Front Microbiol 2022; 12:787554. [PMID: 35087490 PMCID: PMC8787145 DOI: 10.3389/fmicb.2021.787554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
Here we report a new real-time PCR assay using SYBR Green which provides higher sensitivity for the specific detection of low levels of Pneumocystis jirovecii. To do so, two primer sets were designed, targeting the family of genes that code for the most abundant surface protein of Pneumocystis spp., namely the major surface glycoproteins (Msg), and the mitochondrial large subunit rRNA (mtLSUrRNA) multicopy gene, simultaneously detecting two regions. PCR methods are instrumental in detecting these low levels; however, current nested-PCR methods are time-consuming and complex. To validate our new real-time Msg-A/mtLSUrRNA PCR protocol, we compared it with nested-PCR based on the detection of Pneumocystis mitochondrial large subunit rRNA (mtLSUrRNA), one of the main targets used to detect this pathogen. All samples identified as positive by the nested-PCR method were found positive using our new real-time PCR protocol, which also detected P. jirovecii in three nasal aspirate samples that were negative for both rounds of nested-PCR. Furthermore, we read both rounds of the nested-PCR results for comparison and found that some samples with no PCR amplification, or with a feeble band in the first round, correlated with higher Ct values in our real-time Msg-A/mtLSUrRNA PCR. This finding demonstrates the ability of this new single-round protocol to detect low Pneumocystis levels. This new assay provides a valuable alternative for P. jirovecii detection, as it is both rapid and sensitive.
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Affiliation(s)
- Susana Ruiz-Ruiz
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)-Salud Pública, València, Spain.,Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain
| | - Carolina A Ponce
- Programa de Microbiología y Micología, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Nicole Pesantes
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)-Salud Pública, València, Spain.,Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain
| | - Rebeca Bustamante
- Programa de Microbiología y Micología, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Gianna Gatti
- Programa de Microbiología y Micología, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | | | | | | | - Sergio L Vargas
- Programa de Microbiología y Micología, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Fabien Magne
- Programa de Microbiología y Micología, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Enrique J Calderón
- Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain.,Hospital Universitario Virgen del Rocío, Instituto de Biomedicina de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), and Universidad de Sevilla, Seville, Spain
| | - Vicente Pérez-Brocal
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)-Salud Pública, València, Spain.,Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain
| | - Andrés Moya
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)-Salud Pública, València, Spain.,Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBEResp), Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Biología Integrativa de Sistemas (I2Sysbio), Universitat de València and Consejo Superior de Investigaciones Científicas (CSIC), València, Spain
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Friaza V, de Armas Y, Capó V, Morilla R, Plascencia-Hernández A, Pérez-Gómez HR, Iglesias E, Fonte L, de la Horra C, Calderón EJ. Multilocus Genotyping of Pneumocystis jirovecii from Deceased Cuban AIDS Patients Using Formalin-Fixed and Paraffin-Embedded Tissues. J Fungi (Basel) 2021; 7:jof7121042. [PMID: 34947024 PMCID: PMC8706017 DOI: 10.3390/jof7121042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022] Open
Abstract
The results of the genotypic characterization of Pneumocystis jirovecii are described in lung tissue samples from 41 Cubans who died of AIDS with pneumocystosis between 1995 and 2008. Histological sections of the lung preserved as formalin-fixed and paraffin-embedded tissue were examined. PCR amplification and nucleotide sequencing of the two mitochondrial genes (large and small) of the pathogen allowed verification of a predominance of genotype 3 (85T/248C) of the large mitochondrial gene and genotype 3 (160A/196T) of the small mitochondrial gene over a period of 14 years (1995–2008). These results suggest that the 85T/248C//160A/196T genotype circulates with the highest frequency (81.3%) among AIDS patients in Cuba. Multilocus analysis indicates a limited circulation of pathogen genotypes on the island with the existence of a clonal genotype with an epidemic structure. Furthermore, it appears that circulating strains of P. jirovecii have not developed mutations related to sulfonamide resistance. Taken together, the data in this study revealed important elements about pneumocystosis in Cuban patients dying of AIDS and the usefulness of formalin-fixed and paraffin-embedded samples to carry out molecular epidemiology studies of P. jirovecii.
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Affiliation(s)
- Vicente Friaza
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (V.F.); (R.M.); (E.J.C.)
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
| | - Yaxsier de Armas
- Department of Clinical Microbiology Diagnostic, Hospital Center of Institute of Tropical Medicine “Pedro Kourí”, 11400 Havana, Cuba;
- Pathology Department, Hospital Center of Institute of Tropical Medicine “Pedro Kourí”, 11400 Havana, Cuba;
| | - Virginia Capó
- Pathology Department, Hospital Center of Institute of Tropical Medicine “Pedro Kourí”, 11400 Havana, Cuba;
| | - Rubén Morilla
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (V.F.); (R.M.); (E.J.C.)
| | - Arturo Plascencia-Hernández
- Centro Universitario de Ciencias para la Salud, Universidad de Guadalajara, 44100 Guadalajara, Mexico; (A.P.-H.); (H.R.P.-G.)
| | - Héctor R. Pérez-Gómez
- Centro Universitario de Ciencias para la Salud, Universidad de Guadalajara, 44100 Guadalajara, Mexico; (A.P.-H.); (H.R.P.-G.)
| | - Enrique Iglesias
- Centro de Ingeniería Genética y Biotecnología, Departamento de Vacunas, 10600 Havana, Cuba;
| | - Luis Fonte
- Parasitology Department, Institute of Tropical Medicine “Pedro Kourí”, 11400 Havana, Cuba;
| | - Carmen de la Horra
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (V.F.); (R.M.); (E.J.C.)
- Correspondence:
| | - Enrique J. Calderón
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (V.F.); (R.M.); (E.J.C.)
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
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5
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Abstract
Pneumocystis species colonize mammalian lungs and cause deadly pneumonia if the immune system of the host weakens. Each species presents a specificity for a single mammalian host species. Pneumocystis jirovecii infects humans and provokes pneumonia, which is among the most frequent invasive fungal infections. The lack of in vitro culture methods for these fungi complicates their study. Recently, high-throughput sequencing technologies followed by comparative genomics have allowed a better understanding of the mechanisms involved in the sexuality of Pneumocystis organisms. The structure of their mating-type locus corresponding to a fusion of two loci, Plus and Minus, and the concomitant expression of the three mating-type genes revealed that their mode of sexual reproduction is primarily homothallism. This mode is favored by microbial pathogens and involves a single self-compatible mating type that can enter into the sexual cycle on its own. Pneumocystis sexuality is obligatory within the host's lungs during pneumonia in adults, primary infection in children, and possibly colonization. This sexuality participates in cell proliferation, airborne transmission to new hosts, and probably antigenic variation, processes that are crucial to ensure the survival of the fungus. Thus, sexuality is central in the Pneumocystis life cycle. The obligate biotrophic parasitism with obligate sexuality of Pneumocystis is unique among fungi pathogenic to humans. Pneumocystis organisms are similar to the plant fungal obligate biotrophs that complete their entire life cycle within their hosts, including sex, and that are also difficult to grow in vitro.
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6
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Gits-Muselli M, White PL, Mengoli C, Chen S, Crowley B, Dingemans G, Fréalle E, L Gorton R, Guiver M, Hagen F, Halliday C, Johnson G, Lagrou K, Lengerova M, Melchers WJG, Novak-Frazer L, Rautemaa-Richardson R, Scherer E, Steinmann J, Cruciani M, Barnes R, Donnelly JP, Loeffler J, Bretagne S, Alanio A. The Fungal PCR Initiative's evaluation of in-house and commercial Pneumocystis jirovecii qPCR assays: Toward a standard for a diagnostics assay. Med Mycol 2021; 58:779-788. [PMID: 31758173 DOI: 10.1093/mmy/myz115] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 10/22/2019] [Accepted: 10/31/2019] [Indexed: 01/04/2023] Open
Abstract
Quantitative real-time PCR (qPCR) is increasingly used to detect Pneumocystis jirovecii for the diagnosis of Pneumocystis pneumonia (PCP), but there are differences in the nucleic acids targeted, DNA only versus whole nucleic acid (WNA), and also the target genes for amplification. Through the Fungal PCR Initiative, a working group of the International Society for Human and Animal Mycology, a multicenter and monocenter evaluation of PCP qPCR assays was performed. For the multicenter study, 16 reference laboratories from eight different countries, performing 20 assays analyzed a panel consisting of two negative and three PCP positive samples. Aliquots were prepared by pooling residual material from 20 negative or positive- P. jirovecii bronchoalveolar lavage fluids (BALFs). The positive pool was diluted to obtain three concentrations (pure 1:1; 1:100; and 1:1000 to mimic high, medium, and low fungal loads, respectively). The monocenter study compared five in-house and five commercial qPCR assays testing 19 individual BALFs on the same amplification platform. Across both evaluations and for all fungal loads, targeting WNA and the mitochondrial small sub-unit (mtSSU) provided the earliest Cq values, compared to only targeting DNA and the mitochondrial large subunit, the major surface glycoprotein or the beta-tubulin genes. Thus, reverse transcriptase-qPCR targeting the mtSSU gene could serve as a basis for standardizing the P. jirovecii load, which is essential if qPCR is to be incorporated into clinical care pathways as the reference method, accepting that additional parameters such as amplification platforms still need evaluation.
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Affiliation(s)
- Maud Gits-Muselli
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, Paris, France.,Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.,Université de Paris, Paris, France
| | - P Lewis White
- Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, UK
| | | | - Sharon Chen
- Clinical Mycology reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead Hospital, and the University of Sydney, Australia
| | - Brendan Crowley
- Department of Virology, St James's Hospital, Dublin, Ireland
| | | | - Emilie Fréalle
- CHU Lille, Laboratoire de Parasitologie-Mycologie, F-59000 Lille, France & Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR8204-CIIL-Centre for Infection and Immunity of Lille, F-59000 Lille, France
| | - Rebecca L Gorton
- Regional UK Clinical Mycology Network (UK CMN) Laboratory, Dept. Infection Sciences, Health Services Laboratories (HSL) LLP, London, UK
| | - Malcom Guiver
- Public Health Laboratory, National Infection Service Public Health England, Manchester University NHS Foundation Trust, Manchester, UK
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,Department of Medical Microbiology, University Medical Centre Utrecht, Utrecht, The Netherlands.,Laboratory of Medical Mycology, Jining No. 1 People's Hospital, Jining, China
| | - Catriona Halliday
- Clinical Mycology reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, New South Wales Health Pathology, Westmead Hospital, and the University of Sydney, Australia
| | | | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, KU Leuven, and Department of Laboratory Medicine and National Reference Centre for Mycosis, Excellence Centre for Medical Mycology (ECMM), University Hospitals Leuven, Leuven, Belgium
| | - Martina Lengerova
- Department of Internal Medicine - Hematology and Oncology, University Hospital Brno, Brno, Czech Republic
| | - Willem J G Melchers
- Radboud University Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Lily Novak-Frazer
- Mycology Reference Centre Manchester, Manchester University NHS Foundation Trust; and Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Riina Rautemaa-Richardson
- Department of Infectious Diseases and the Mycology Reference Centre Manchester, Manchester University NHS Foundation Trust; and Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Emeline Scherer
- Department of Parasitology-Mycology, University Hospital of Besançon, Besançon, France
| | - Joerg Steinmann
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Klinikum Nürnberg, Paracelsus Medical University, Nuremberg, Germany.,Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Mario Cruciani
- Infectious Diseases Unit, San Bonifacio Hospital, Verona, Italy
| | | | | | - Juergen Loeffler
- University Hospital Wuerzburg, Medical Hospital II, C11, Wuerzburg, Germany
| | - Stéphane Bretagne
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, Paris, France.,Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.,Université de Paris, Paris, France
| | - Alexandre Alanio
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, Paris, France.,Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.,Université de Paris, Paris, France
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7
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Wills NK, Lawrence DS, Botsile E, Tenforde MW, Jarvis JN. The prevalence of laboratory-confirmed Pneumocystis jirovecii in HIV-infected adults in Africa: A systematic review and meta-analysis. Med Mycol 2021; 59:802-812. [PMID: 33578417 DOI: 10.1093/mmy/myab002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The epidemiology of Pneumocystis jirovecii, known to colonize the respiratory tract and cause a life-threatening HIV-associated pneumonia (PCP), is poorly described in Africa. We conducted a systematic review to evaluate P. jirovecii prevalence in African HIV-positive adults with or without respiratory symptoms. METHODS We searched Medline, Embase, Cochrane library, Africa-Wide, and Web of Science for studies employing PCR and/or microscopy for P. jirovecii detection in respiratory samples from HIV-positive adults in Africa between 1995 and 2020. Prevalence with respiratory symptoms was pooled using random-effect meta-analysis, and stratified by laboratory method, sample tested, study setting, CD4 count, and trimethoprim/sulfamethoxazole prophylaxis. Colonization prevalence in asymptomatic adults and in adults with non-PCP respiratory disease was described, and quantitative PCR (qPCR) thresholds to distinguish colonization from microscopy-confirmed PCP reviewed. RESULTS Thirty-two studies were included, with 27 studies (87%) at high risk of selection bias. P. jirovecii was detected in 19% [95% confidence interval (CI): 12-27%] of 3583 symptomatic and in 9% [95% CI: 0-45%] of 140 asymptomatic adults. Among symptomatic adults, prevalence was 22% [95% CI: 12-35%] by PCR and 15% [95% CI: 9-23%] by microscopy. Seven percent of 435 symptomatic adults had PCR-detected Pneumocystis colonization without evidence of PCP [95% CI: 5-10%, four studies]. One study established a qPCR cutoff of 78 copies/5μl of DNA in 305 induced sputum samples to distinguish Pneumocystis colonization from microscopy-confirmed PCP. CONCLUSION Despite widened access to HIV services, P. jirovecii remains common in Africa. Prevalence estimates and qPCR-based definitions of colonization are limited, and overall quality of studies is low.
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Affiliation(s)
- Nicola K Wills
- Welcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, 7925, South Africa.,Department of Clinical Research, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.,Department of Medicine, Groote Schuur Hospital University of Cape Town, Cape Town, 7925, South Africa
| | - David S Lawrence
- Department of Clinical Research, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.,Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Elizabeth Botsile
- Department of Medicine, Princess Marina Hospital, Gaborone, Botswana
| | - Mark W Tenforde
- Division of Allergy and Infectious Diseases, Department of Medicine, University of Washington School of Medicine, Seattle, WA, 98195, USA.,Department of Epidemiology, University of Washington School of Public Health, Seattle, 98195, WA, USA
| | - Joseph N Jarvis
- Department of Clinical Research, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.,Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
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8
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Le Gal S, Bonnet P, Huguenin A, Chapelle C, Boulic P, Tonnelier JM, Moal MC, Gut-Gobert C, Barnier A, Nevez G. The shift from pulmonary colonization to Pneumocystis pneumonia. Med Mycol 2020; 59:510-513. [PMID: 33369642 DOI: 10.1093/mmy/myaa107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/24/2020] [Accepted: 12/04/2020] [Indexed: 11/13/2022] Open
Abstract
Pulmonary specimen pairs from five patients who presented with pulmonary colonization and later developed Pneumocystis Pneumonia (PcP) were retrospectively examined for P. jirovecii genotyping. A match of genotypes in pulmonary specimen pairs of three patients was observed, whereas a partial match and a mismatch were observed in the fourth and fifth patients, respectively. The genotyping results suggest that the colonization state can differ from PcP but can also represent the incubation period of PcP. Clinicians should not systematically rule out the treatment of putative colonized patients and should at least discuss the initiation of prophylaxis on a case-by-case basis.
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Affiliation(s)
- Solène Le Gal
- Université de Brest, Université d'Angers, GEIHP, Brest, France.,Laboratory of Parasitology and Mycology, Brest University Hospital, Brest, France
| | - Pierre Bonnet
- Université de Brest, Université d'Angers, GEIHP, Brest, France.,Laboratory of Parasitology and Mycology, Brest University Hospital, Brest, France
| | - Antoine Huguenin
- EA 7510, ESCAPE, Laboratory of Parasitology and Mycology, Université de Reims Champagne-Ardenne, 51 rue Cognacq Jay, 51092 Reims CEDEX, France
| | - Célia Chapelle
- Université de Brest, Université d'Angers, GEIHP, Brest, France
| | - Pierrick Boulic
- Université de Brest, Université d'Angers, GEIHP, Brest, France
| | | | | | | | - Aude Barnier
- Pneumology and Internal Medicine, Brest University Hospital, Brest, France
| | - Gilles Nevez
- Université de Brest, Université d'Angers, GEIHP, Brest, France.,Laboratory of Parasitology and Mycology, Brest University Hospital, Brest, France
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9
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Consensus Multilocus Sequence Typing Scheme for Pneumocystis jirovecii. J Fungi (Basel) 2020; 6:jof6040259. [PMID: 33143112 PMCID: PMC7711988 DOI: 10.3390/jof6040259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/10/2020] [Accepted: 10/18/2020] [Indexed: 12/26/2022] Open
Abstract
Pneumocystis jirovecii is an opportunistic human pathogenic fungus causing severe pneumonia mainly in immunocompromised hosts. Multilocus sequence typing (MLST) remains the gold standard for genotyping of this unculturable fungus. However, the lack of a consensus scheme impedes a global comparison, large scale population studies and the development of a global MLST database. To overcome this problem this study compared all genetic regions (19 loci) currently used in 31 different published Pneumocystis MLST schemes. The most diverse/commonly used eight loci, β-TUB, CYB, DHPS, ITS1, ITS1/2, mt26S and SOD, were further assess for their ability to be successfully amplified and sequenced, and for their discriminatory power. The most successful loci were tested to identify genetically related and unrelated cases. A new consensus MLST scheme consisting of four genetically independent loci: β-TUB, CYB, mt26S and SOD, is herein proposed for standardised P. jirovecii typing, successfully amplifying low and high fungal burden specimens, showing adequate discriminatory power, and correctly identifying suspected related and unrelated isolates. The new consensus MLST scheme, if accepted, will for the first time provide a powerful tool to investigate outbreak settings and undertake global epidemiological studies shedding light on the spread of this important human fungal pathogen.
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Gits-Muselli M, Campagne P, Desnos-Ollivier M, Le Pape P, Bretagne S, Morio F, Alanio A. Comparison of MultiLocus Sequence Typing (MLST) and Microsatellite Length Polymorphism (MLP) for Pneumocystis jirovecii genotyping. Comput Struct Biotechnol J 2020; 18:2890-2896. [PMID: 33163149 PMCID: PMC7593342 DOI: 10.1016/j.csbj.2020.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/28/2020] [Accepted: 10/02/2020] [Indexed: 01/02/2023] Open
Abstract
Pneumocystis jirovecii is an atypical fungus responsible for severe respiratory infections, often reported as local outbreaks in immunocompromised patients. Epidemiology of this infection, and transmission risk emphasises the need for developing genotyping techniques. Currently, two methods have emerged: Multilocus Sequence typing (MLST) and microsatellite length polymorphism (MLP). Here we compare an MLST strategy, including 2 nuclear loci and 2 mitochondrial loci, with an MLP strategy including 6 nuclear markers using 37 clinical PCR-positive respiratory samples from two French hospitals. Pneumocystis jirovecii MLST and MLP provided 30 and 35 different genotypes respectively. A higher number of mixed infections was detected using MLP (48.6% vs. 13.5% respectively; p = 0.002). Only one MLP marker (STR279) was statistically associated with the geographical origin of samples. Haplotype network inferred using the available genotypes yielded expanded network for MLP, characterized by more mutational steps as compared to MLST, suggesting that the MLP approach is more resolutive to separate genotypes. The correlation between genetic distances calculated based on MLST and MLP was modest with a R2 value = 0.32 (p < 0.001). Finally, both genotyping methods fulfilled important criteria: (i) a discriminatory power from 97.5% to 99.5% and (ii) being quick and convenient genotyping tools. While MLP appeared highly resolutive regarding genotypes mixture within samples, using one genotyping method rather than the other may also depend on the context (i.e., MLST for investigation of suspected clonal outbreaks versus MLP for population structure study) as well as local facilities.
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Affiliation(s)
- Maud Gits-Muselli
- Laboratoire de Parasitologie-Mycologie; AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France.,Institut Pasteur, CNRS, unité de Mycologie Moléculaire, Centre National de référence Mycoses invasives et Antifongiques (CNRMA), UMR2000, Paris, France
| | - Pascal Campagne
- Hub of Bioinformatics and Biostatistics - Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Marie Desnos-Ollivier
- Institut Pasteur, CNRS, unité de Mycologie Moléculaire, Centre National de référence Mycoses invasives et Antifongiques (CNRMA), UMR2000, Paris, France
| | - Patrice Le Pape
- Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, Nantes, France.,Département de Parasitologie et Mycologie Médicale, EA1155 IICiMed, Institut de Recherche en Santé 2, Université de Nantes, Nantes Atlantique Universités, Nantes, France
| | - Stéphane Bretagne
- Laboratoire de Parasitologie-Mycologie; AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France.,Institut Pasteur, CNRS, unité de Mycologie Moléculaire, Centre National de référence Mycoses invasives et Antifongiques (CNRMA), UMR2000, Paris, France
| | - Florent Morio
- Laboratoire de Parasitologie-Mycologie, Institut de Biologie, CHU Nantes, Nantes, France.,Département de Parasitologie et Mycologie Médicale, EA1155 IICiMed, Institut de Recherche en Santé 2, Université de Nantes, Nantes Atlantique Universités, Nantes, France
| | - Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie; AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France.,Institut Pasteur, CNRS, unité de Mycologie Moléculaire, Centre National de référence Mycoses invasives et Antifongiques (CNRMA), UMR2000, Paris, France
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11
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Bonnet P, Le Gal S, Calderon E, Delhaes L, Quinio D, Robert-Gangneux F, Ramel S, Nevez G. Pneumocystis jirovecii in Patients With Cystic Fibrosis: A Review. Front Cell Infect Microbiol 2020; 10:571253. [PMID: 33117730 PMCID: PMC7553083 DOI: 10.3389/fcimb.2020.571253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/14/2020] [Indexed: 12/12/2022] Open
Abstract
Pneumocystis pneumonia (PCP) remains the most frequent AIDS-defining illness in developed countries. This infection also occurs in non-AIDS immunosuppressed patients, e.g., those who have undergone an organ transplantation. Moreover, mild Pneumocystis jirovecii infections related to low pulmonary fungal burden, frequently designated as pulmonary colonization, occurs in patients with chronic pulmonary diseases, e.g., cystic fibrosis (CF). Indeed, this autosomal recessive disorder alters mucociliary clearance leading to bacterial and fungal colonization of the airways. This mini-review compiles and discusses available information on P. jirovecii and CF. It highlights significant differences in the prevalence of P. jirovecii pulmonary colonization in European and Brazilian CF patients. It also describes the microbiota associated with P. jirovecii in CF patients colonized by P. jirovecii. Furthermore, we have described P. jirovecii genomic diversity in colonized CF patients. In addition of pulmonary colonization, it appears that PCP can occur in CF patients specifically after lung transplantation, thus requiring preventive strategies. In other respects, Pneumocystis primary infection is a worldwide phenomenon occurring in non-immunosuppressed infants within their first months. The primary infection is mostly asymptomatic but it can also present as a benign self-limiting infection. It probably occurs in the same manner in CF infants. Nonetheless, two cases of severe Pneumocystis primary infection mimicking PCP in CF infants have been reported, the genetic disease appearing in these circumstances as a risk factor of PCP while the host-pathogen interaction in older children and adults with pulmonary colonization remains to be clarified.
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Affiliation(s)
- Pierre Bonnet
- Laboratoire de Parasitologie et Mycologie, Hôpital de La Cavale Blanche, CHU de Brest, Brest, France
| | - Solène Le Gal
- Laboratoire de Parasitologie et Mycologie, Hôpital de La Cavale Blanche, CHU de Brest, Brest, France.,Groupe d'Etude des Interactions Hôte-Pathogène (ER, GEIHP), Université d'Angers, Université de Brest, Brest, France
| | - Enrique Calderon
- CIBER de Epidemiologia y Salud Publica and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Seville, Spain
| | - Laurence Delhaes
- Laboratory of Parasitology and Mycology, Bordeaux University Hospital, Bordeaux, France Inserm U1045 - University of Bordeaux, Bordeaux, France
| | - Dorothée Quinio
- Laboratoire de Parasitologie et Mycologie, Hôpital de La Cavale Blanche, CHU de Brest, Brest, France
| | - Florence Robert-Gangneux
- Univ Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé Environnement Travail), UMR_S 1085, Rennes, France
| | - Sophie Ramel
- Centre de Ressources et de Compétences de la Mucoviscidose, Fondation Ildys, Roscoff, France
| | - Gilles Nevez
- Laboratoire de Parasitologie et Mycologie, Hôpital de La Cavale Blanche, CHU de Brest, Brest, France.,Groupe d'Etude des Interactions Hôte-Pathogène (ER, GEIHP), Université d'Angers, Université de Brest, Brest, France
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12
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Abstract
Environmental exposure has a significant impact on human health. While some airborne fungi can cause life-threatening infections, the impact of environment on fungal spore dispersal and transmission is poorly understood. The democratization of shotgun metagenomics allows us to explore important questions about fungal propagation. We focus on Pneumocystis, a genus of host-specific fungi that infect mammals via airborne particles. In humans, Pneumocystis jirovecii causes lethal infections in immunocompromised patients if untreated, although its environmental reservoir and transmission route remain unclear. Environmental exposure has a significant impact on human health. While some airborne fungi can cause life-threatening infections, the impact of environment on fungal spore dispersal and transmission is poorly understood. The democratization of shotgun metagenomics allows us to explore important questions about fungal propagation. We focus on Pneumocystis, a genus of host-specific fungi that infect mammals via airborne particles. In humans, Pneumocystis jirovecii causes lethal infections in immunocompromised patients if untreated, although its environmental reservoir and transmission route remain unclear. Here, we attempt to clarify, by analyzing human exposome metagenomic data sets, whether humans are exposed to different Pneumocystis species present in the air but only P. jirovecii cells are able to replicate or whether they are selectively exposed to P. jirovecii. Our analysis supports the latter hypothesis, which is consistent with a local transmission model. These data also suggest that healthy carriers are a major driver for the transmission.
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Le Gal S, Hoarau G, Bertolotti A, Negri S, Le Nan N, Bouchara JP, Papon N, Blanchet D, Demar M, Nevez G. Pneumocystis jirovecii Diversity in Réunion, an Overseas French Island in Indian Ocean. Front Microbiol 2020; 11:127. [PMID: 32117149 PMCID: PMC7019000 DOI: 10.3389/fmicb.2020.00127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/20/2020] [Indexed: 12/17/2022] Open
Abstract
Data on Pneumocystis jirovecii characteristics from the overseas French territories are still scarce whereas numerous data on P. jirovecii genotypes are available for metropolitan France. The main objective of the present study was to identify P. jirovecii multilocus genotypes in patients living in Réunion and to compare them with those identified using the same method in metropolitan France and in French Guiana. Archival P. jirovecii specimens from immunosuppressed patients, 16 living in Réunion (a French island of the Indian ocean), six living in French Guiana (a South-American French territory), and 24 living in Brest (Brittany, metropolitan France) were examined at the large subunit rRNA (mtLSUrRNA) genes, cytochrome b (CYB), and superoxide dismutase (SOD) genes using PCR assays and direct sequencing. A total of 23 multi-locus genotypes (MLG) were identified combining mtLSUrRNA, CYB, and SOD alleles, i.e., six in Reunionese patients, three in Guianese patients, and 15 in Brest patients. Only one MLG (mtLSU1-CYB1-SOD2) was shared by Reunionese and Guianese patients (one patient from each region) whereas none of the 22 remaining MLG were shared by the 3 patient groups. A total of eight MLG were newly identified, three in Réunion and five in Brest. These results that were obtained through a retrospective investigation of a relatively low number of P. jirovecii specimens, provides original and first data on genetic diversity of P. jirovecii in Réunion island. The results suggest that P. jirovecii organisms from Réunion present specific characteristics compared to other P. jirovecii organisms from metropolitan France and French Guiana.
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Affiliation(s)
- Solène Le Gal
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France.,Laboratory of Mycology and Parasitology, CHRU de Brest, Brest, France
| | - Gautier Hoarau
- Department of Microbiology, CHU La Réunion, Saint Pierre, France
| | | | - Steven Negri
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France
| | - Nathan Le Nan
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France
| | - Jean-Philippe Bouchara
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France
| | - Nicolas Papon
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France
| | - Denis Blanchet
- Laboratory of Mycology and Parasitology, Andrée Rosemon Hospital, Cayenne, French Guiana.,Equipe EA3593 - Ecosystèmes Amazoniens et Pathologie Tropicale, Université de Guyane, Cayenne, French Guiana
| | - Magalie Demar
- Laboratory of Mycology and Parasitology, Andrée Rosemon Hospital, Cayenne, French Guiana.,Equipe EA3593 - Ecosystèmes Amazoniens et Pathologie Tropicale, Université de Guyane, Cayenne, French Guiana
| | - Gilles Nevez
- Groupe d'Étude des Interactions Hôte-Pathogène (GEIHP) EA 3142, Université d'Angers-Université de Brest, Angers, France.,Laboratory of Mycology and Parasitology, CHRU de Brest, Brest, France
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14
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Dellière S, Gits-Muselli M, Bretagne S, Alanio A. Outbreak-Causing Fungi: Pneumocystis jirovecii. Mycopathologia 2019; 185:783-800. [PMID: 31782069 DOI: 10.1007/s11046-019-00408-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/15/2019] [Indexed: 12/17/2022]
Abstract
Pneumocystis jirovecii pneumonia (PCP) is an important cause of morbidity in immunocompromised patients, with a higher mortality in non-HIV than in HIV patients. P. jirovecii is one of the rare transmissible pathogenic fungi and the only one that depends fully on the host to survive and proliferate. Transmissibility among humans is one of the main specificities of P. jirovecii. Hence, the description of multiple outbreaks raises questions regarding preventive care management of the disease, especially in the non-HIV population. Indeed, chemoprophylaxis is well codified in HIV patients but there is a trend for modifications of the recommendations in the non-HIV population. In this review, we aim to discuss the mode of transmission of P. jirovecii, identify published outbreaks of PCP and describe molecular tools available to study these outbreaks. Finally, we discuss public health and infection control implications of PCP outbreaks in hospital setting for in- and outpatients.
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Affiliation(s)
- Sarah Dellière
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université de Paris, Paris, France
- Molecular Mycology Unit, CNRS UMR2000, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France
| | - Maud Gits-Muselli
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université de Paris, Paris, France
- Molecular Mycology Unit, CNRS UMR2000, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France
| | - Stéphane Bretagne
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université de Paris, Paris, France
- Molecular Mycology Unit, CNRS UMR2000, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France
- National Reference Center for Invasive Mycoses and Antifungals (NRCMA), Institut Pasteur, Paris, France
| | - Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université de Paris, Paris, France.
- Molecular Mycology Unit, CNRS UMR2000, Institut Pasteur, 25 rue du Dr Roux, 75724, Paris Cedex 15, France.
- National Reference Center for Invasive Mycoses and Antifungals (NRCMA), Institut Pasteur, Paris, France.
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15
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White PL, Price JS, Backx M. Pneumocystis jirovecii Pneumonia: Epidemiology, Clinical Manifestation and Diagnosis. CURRENT FUNGAL INFECTION REPORTS 2019. [DOI: 10.1007/s12281-019-00349-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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16
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Expression and Immunostaining Analyses Suggest that Pneumocystis Primary Homothallism Involves Trophic Cells Displaying Both Plus and Minus Pheromone Receptors. mBio 2019; 10:mBio.01145-19. [PMID: 31289178 PMCID: PMC6747714 DOI: 10.1128/mbio.01145-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The fungi belonging to the genus Pneumocystis may cause severe pneumonia in immunocompromised humans, a disease that can be fatal if not treated. This disease is nowadays one of the most frequent invasive fungal infections worldwide. Whole-genome sequencing revealed that the sexuality of these fungi involves a single partner that can self-fertilize. Here, we report that two receptors recognizing specifically excreted pheromones are involved in this self-fertility within infected human lungs. Using fluorescent antibodies binding specifically to these receptors, we observed that most often, the fungal cells display both receptors at their surface. These pheromone-receptor systems might play a role in mate recognition and/or postfertilization events. They constitute an integral part of the Pneumocystis obligate sexuality within human lungs, a cycle that is necessary for the dissemination of the fungus to new individuals. The genus Pneumocystis encompasses fungal species that colonize mammals’ lungs with host specificity. Should the host immune system weaken, the fungal species can cause severe pneumonia. The life cycle of these pathogens is poorly known, mainly because an in vitro culture method has not been established. Both asexual and sexual cycles would occur. Trophic cells, the predominant forms during infection, could multiply asexually but also enter into a sexual cycle. Comparative genomics revealed a single mating type locus, including plus and minus genes, suggesting that primary homothallism involving self-fertility of each strain is the mode of reproduction of Pneumocystis species. We identified and analyzed the expression of the mam2 and map3 genes encoding the receptors for plus and minus pheromones using reverse transcriptase PCR, in both infected mice and bronchoalveolar lavage fluid samples from patients with Pneumocystis pneumonia. Both receptors were most often concomitantly expressed during infection, revealing that both pheromone-receptor systems are involved in the sexual cycle. The map3 transcripts were subject to alternative splicing. Using immunostaining, we investigated the presence of the pheromone receptors at the surfaces of Pneumocystis cells from a patient. The staining tools were first assessed in Saccharomyces cerevisiae displaying the Pneumocystis receptors at their cellular surface. Both receptors were present at the surfaces of the vast majority of the cells that were likely trophic forms. The receptors might have a role in mate recognition and/or postfertilization events. Their presence at the cell surface might facilitate outbreeding versus inbreeding of self-fertile strains.
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Genotyping of Pneumocystis jirovecii by Use of a New Simplified Nomenclature System Based on the Internal Transcribed Spacer Regions and 5.8S rRNA Gene of the rRNA Operon. J Clin Microbiol 2019; 57:JCM.02012-18. [PMID: 30918046 DOI: 10.1128/jcm.02012-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/12/2019] [Indexed: 12/16/2022] Open
Abstract
Genotyping based on internal transcribed spacer 1 (ITS1) and ITS2 of the rRNA operon has played an important role in understanding the transmission and epidemiology of Pneumocystis jirovecii, one of the major opportunistic pathogens in individuals with AIDS and other immunocompromised individuals. The widespread use of this typing system has resulted in several problems, including inconsistent genotype nomenclatures, difficult data transferability, and complicated interpretation of the length variation in multiple homopolymeric tracts. The aim of this study was to establish a new, simplified genotype nomenclature system for P. jirovecii based on the ITS1 and ITS2 sequences. We first analyzed the complete ITS1, 5.8S rRNA gene, and ITS2 sequences (termed ITS1-5.8S-ITS2) in 27 recent P. jirovecii isolates from China and identified 18 unique genotypes. Subsequently, we performed a comprehensive classification of more than 400 ITS1- and ITS2-related sequences from GenBank and an in-depth evaluation of the length variation of multiple homopolymeric tracts within ITS1-5.8S-ITS2. Integration of the results from these analyses led to a new, simplified genotype nomenclature system including 62 unique ITS1-5.8S-ITS2 genotypes, simply designated types 1 through 62. This new system offers several advantages over traditional ITS1- and ITS2-based typing systems, including a simpler analysis and interpretation process, a higher discriminative power, and no limitation in assigning potential new genotypes. This new system is expected to facilitate the standardization of P. jirovecii genotyping and easy data exchanges across different laboratories.
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Zhang P, Liu C, Zheng X, Wu L, Liu Z, Liao B, Shi Y, Li X, Xu J, Chen S. Full-Length Multi-Barcoding: DNA Barcoding from Single Ingredient to Complex Mixtures. Genes (Basel) 2019; 10:E343. [PMID: 31067783 PMCID: PMC6562688 DOI: 10.3390/genes10050343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/22/2019] [Accepted: 04/29/2019] [Indexed: 11/22/2022] Open
Abstract
DNA barcoding has been used for decades, although it has mostly been applied to somesingle-species. Traditional Chinese medicine (TCM), which is mainly used in the form ofcombination-one type of the multi-species, identification is crucial for clinical usage.Next-generation Sequencing (NGS) has been used to address this authentication issue for the pastfew years, but conventional NGS technology is hampered in application due to its short sequencingreads and systematic errors. Here, a novel method, Full-length multi-barcoding (FLMB) vialong-read sequencing, is employed for the identification of biological compositions in herbalcompound formulas in adequate and well controlled studies. By directly sequencing the full-lengthamplicons of ITS2 and psbA-trnH through single-molecule real-time (SMRT) technology, thebiological composition of a classical prescription Sheng-Mai-San (SMS) was analyzed. At the sametime, clone-dependent Sanger sequencing was carried out as a parallel control. Further, anotherformula-Sanwei-Jili-San (SJS)-was analyzed with genes of ITS2 and CO1. All the ingredients inthe samples of SMS and SJS were successfully authenticated at the species level, and 11 exogenousspecies were also checked, some of which were considered as common contaminations in theseproducts. Methodology analysis demonstrated that this method was sensitive, accurate andreliable. FLMB, a superior but feasible approach for the identification of biological complexmixture, was established and elucidated, which shows perfect interpretation for DNA barcodingthat could lead its application in multi-species mixtures.
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Affiliation(s)
- Peng Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Chunsheng Liu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
| | - Xiasheng Zheng
- Guangdong Provincial Key Laboratory of New Drug Development and Research of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
| | - Lan Wu
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Zhixiang Liu
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Baosheng Liao
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Yuhua Shi
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Xiwen Li
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Jiang Xu
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Shilin Chen
- Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of ChineseMateria Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
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Dellière S, Guery R, Candon S, Rammaert B, Aguilar C, Lanternier F, Chatenoud L, Lortholary O. Understanding Pathogenesis and Care Challenges of Immune Reconstitution Inflammatory Syndrome in Fungal Infections. J Fungi (Basel) 2018; 4:E139. [PMID: 30562960 PMCID: PMC6308948 DOI: 10.3390/jof4040139] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/14/2018] [Accepted: 12/15/2018] [Indexed: 12/16/2022] Open
Abstract
Immune deficiency of diverse etiology, including human immunodeficiency virus (HIV), antineoplastic agents, immunosuppressive agents used in solid organ recipients, immunomodulatory therapy, and other biologics, all promote invasive fungal infections. Subsequent voluntary or unintended immune recovery may induce an exaggerated inflammatory response defining immune reconstitution inflammatory syndrome (IRIS), which causes significant mortality and morbidity. Fungal-associated IRIS raises several diagnostic and management issues. Mostly studied with Cryptococcus, it has also been described with other major fungi implicated in human invasive fungal infections, such as Pneumocystis, Aspergillus, Candida, and Histoplasma. Furthermore, the understanding of IRIS pathogenesis remains in its infancy. This review summarizes current knowledge regarding the clinical characteristics of IRIS depending on fungal species and existing strategies to predict, prevent, and treat IRIS in this patient population, and tries to propose a common immunological background to fungal IRIS.
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Affiliation(s)
- Sarah Dellière
- Medical School, Paris-Descartes University, APHP, Necker-Enfants Malades Hospital, Infectious Disease Center Necker-Pasteur, IHU Imagine, 75015 Paris, France.
| | - Romain Guery
- Medical School, Paris-Descartes University, APHP, Necker-Enfants Malades Hospital, Infectious Disease Center Necker-Pasteur, IHU Imagine, 75015 Paris, France.
| | - Sophie Candon
- Medical School, Paris-Descartes University, INSERM U1151-CNRS UMR 8253APHP, Necker-Enfants Malades Hospital, APHP, Clinical Immunology, 75015 Paris, France.
| | - Blandine Rammaert
- Medical School, Poitiers University, Poitiers, France; Poitiers University Hospital, Infectious Disease Unit, Poitiers, France; INSERM U1070, 86022 Poitiers, France.
| | - Claire Aguilar
- Medical School, Paris-Descartes University, APHP, Necker-Enfants Malades Hospital, Infectious Disease Center Necker-Pasteur, IHU Imagine, 75015 Paris, France.
| | - Fanny Lanternier
- Medical School, Paris-Descartes University, APHP, Necker-Enfants Malades Hospital, Infectious Disease Center Necker-Pasteur, IHU Imagine, 75015 Paris, France.
- Pasteur Institute, Molecular Mycology Unit, National Reference Center for Invasive Fungal Disease and Antifungals, CNRS UMR 2000, 75015 Paris, France.
| | - Lucienne Chatenoud
- Medical School, Paris-Descartes University, INSERM U1151-CNRS UMR 8253APHP, Necker-Enfants Malades Hospital, APHP, Clinical Immunology, 75015 Paris, France.
| | - Olivier Lortholary
- Medical School, Paris-Descartes University, APHP, Necker-Enfants Malades Hospital, Infectious Disease Center Necker-Pasteur, IHU Imagine, 75015 Paris, France.
- Pasteur Institute, Molecular Mycology Unit, National Reference Center for Invasive Fungal Disease and Antifungals, CNRS UMR 2000, 75015 Paris, France.
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Brunet K, Alanio A, Lortholary O, Rammaert B. Reactivation of dormant/latent fungal infection. J Infect 2018; 77:463-468. [DOI: 10.1016/j.jinf.2018.06.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/23/2018] [Accepted: 06/25/2018] [Indexed: 12/18/2022]
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White PL, Price JS, Backx M. Therapy and Management of Pneumocystis jirovecii Infection. J Fungi (Basel) 2018; 4:E127. [PMID: 30469526 PMCID: PMC6313306 DOI: 10.3390/jof4040127] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/08/2018] [Accepted: 11/11/2018] [Indexed: 12/21/2022] Open
Abstract
The rates of Pneumocystis pneumonia (PcP) are increasing in the HIV-negative susceptible population. Guidance for the prophylaxis and treatment of PcP in HIV, haematology, and solid-organ transplant (SOT) recipients is available, although for many other populations (e.g., auto-immune disorders) there remains an urgent need for recommendations. The main drug for both prophylaxis and treatment of PcP is trimethoprim/sulfamethoxazole, but resistance to this therapy is emerging, placing further emphasis on the need to make a mycological diagnosis using molecular based methods. Outbreaks in SOT recipients, particularly renal transplants, are increasingly described, and likely caused by human-to-human spread, highlighting the need for efficient infection control policies and sensitive diagnostic assays. Widespread prophylaxis is the best measure to gain control of outbreak situations. This review will summarize diagnostic options, cover prophylactic and therapeutic management in the main at risk populations, while also covering aspects of managing resistant disease, outbreak situations, and paediatric PcP.
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Affiliation(s)
- P Lewis White
- Public Health Wales Microbiology Cardiff, UHW, Heath Park, Cardiff CF14 4XW, UK.
| | - Jessica S Price
- Public Health Wales Microbiology Cardiff, UHW, Heath Park, Cardiff CF14 4XW, UK.
| | - Matthijs Backx
- Public Health Wales Microbiology Cardiff, UHW, Heath Park, Cardiff CF14 4XW, UK.
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Cissé OH, Hauser PM. Genomics and evolution of Pneumocystis species. INFECTION GENETICS AND EVOLUTION 2018; 65:308-320. [PMID: 30138710 DOI: 10.1016/j.meegid.2018.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 01/20/2023]
Abstract
The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect exclusively mammals and present a strict host species specificity. These species have co-diverged with their hosts for long periods of time (> 100 MYA). Details of their biology and evolution are fragmentary mainly because of a lack of an established long-term culture system. Recent genomic advances have unlocked new areas of research and allow new hypotheses to be tested. We review here new findings of the genomic studies in relation with the evolutionary trajectory of these fungi and discuss the impact of genomic data analysis in the context of the population genetics. The combination of slow genome decay and limited expansion of specific gene families and introns reflect intimate interactions of these species with their hosts. The evolutionary adaptation of these organisms is profoundly influenced by their population structure, which in turn is determined by intrinsic features such as their self-fertilizing mating system, high host specificity, long generation times, and transmission mode. Essential key questions concerning their adaptation and speciation remain to be answered. The next cornerstone will consist in the establishment of a long-term culture system and genetic manipulation that should allow unravelling the driving forces of Pneumocystis species evolution.
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Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland.
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23
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Ma L, Cissé OH, Kovacs JA. A Molecular Window into the Biology and Epidemiology of Pneumocystis spp. Clin Microbiol Rev 2018; 31:e00009-18. [PMID: 29899010 PMCID: PMC6056843 DOI: 10.1128/cmr.00009-18] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pneumocystis, a unique atypical fungus with an elusive lifestyle, has had an important medical history. It came to prominence as an opportunistic pathogen that not only can cause life-threatening pneumonia in patients with HIV infection and other immunodeficiencies but also can colonize the lungs of healthy individuals from a very early age. The genus Pneumocystis includes a group of closely related but heterogeneous organisms that have a worldwide distribution, have been detected in multiple mammalian species, are highly host species specific, inhabit the lungs almost exclusively, and have never convincingly been cultured in vitro, making Pneumocystis a fascinating but difficult-to-study organism. Improved molecular biologic methodologies have opened a new window into the biology and epidemiology of Pneumocystis. Advances include an improved taxonomic classification, identification of an extremely reduced genome and concomitant inability to metabolize and grow independent of the host lungs, insights into its transmission mode, recognition of its widespread colonization in both immunocompetent and immunodeficient hosts, and utilization of strain variation to study drug resistance, epidemiology, and outbreaks of infection among transplant patients. This review summarizes these advances and also identifies some major questions and challenges that need to be addressed to better understand Pneumocystis biology and its relevance to clinical care.
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Affiliation(s)
- Liang Ma
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
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24
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Cissé OH, Ma L, Wei Huang D, Khil PP, Dekker JP, Kutty G, Bishop L, Liu Y, Deng X, Hauser PM, Pagni M, Hirsch V, Lempicki RA, Stajich JE, Cuomo CA, Kovacs JA. Comparative Population Genomics Analysis of the Mammalian Fungal Pathogen Pneumocystis. mBio 2018; 9:e00381-18. [PMID: 29739910 PMCID: PMC5941068 DOI: 10.1128/mbio.00381-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/19/2018] [Indexed: 01/14/2023] Open
Abstract
Pneumocystis species are opportunistic mammalian pathogens that cause severe pneumonia in immunocompromised individuals. These fungi are highly host specific and uncultivable in vitro Human Pneumocystis infections present major challenges because of a limited therapeutic arsenal and the rise of drug resistance. To investigate the diversity and demographic history of natural populations of Pneumocystis infecting humans, rats, and mice, we performed whole-genome and large-scale multilocus sequencing of infected tissues collected in various geographic locations. Here, we detected reduced levels of recombination and variations in historical demography, which shape the global population structures. We report estimates of evolutionary rates, levels of genetic diversity, and population sizes. Molecular clock estimates indicate that Pneumocystis species diverged before their hosts, while the asynchronous timing of population declines suggests host shifts. Our results have uncovered complex patterns of genetic variation influenced by multiple factors that shaped the adaptation of Pneumocystis populations during their spread across mammals.IMPORTANCE Understanding how natural pathogen populations evolve and identifying the determinants of genetic variation are central issues in evolutionary biology. Pneumocystis, a fungal pathogen which infects mammals exclusively, provides opportunities to explore these issues. In humans, Pneumocystis can cause a life-threatening pneumonia in immunosuppressed individuals. In analysis of different Pneumocystis species infecting humans, rats, and mice, we found that there are high infection rates and that natural populations maintain a high level of genetic variation despite low levels of recombination. We found no evidence of population structuring by geography. Our comparisons of the times of divergence of these species to their respective hosts suggest that Pneumocystis may have undergone recent host shifts. The results demonstrate that Pneumocystis strains are widely disseminated geographically and provide a new understanding of the evolution of these pathogens.
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Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Liang Ma
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Da Wei Huang
- Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Pavel P Khil
- Department of Laboratory Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - John P Dekker
- Department of Laboratory Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Geetha Kutty
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Lisa Bishop
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Yueqin Liu
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Xilong Deng
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Marco Pagni
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Vanessa Hirsch
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, USA
| | - Richard A Lempicki
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Jason E Stajich
- Department of Plant Pathology and Microbiology and Institute for Integrative Genome Biology, University of California, Riverside, Riverside, California, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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25
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Charpentier E, Garnaud C, Wintenberger C, Bailly S, Murat JB, Rendu J, Pavese P, Drouet T, Augier C, Malvezzi P, Thiébaut-Bertrand A, Mallaret MR, Epaulard O, Cornet M, Larrat S, Maubon D. Added Value of Next-Generation Sequencing for Multilocus Sequence Typing Analysis of a Pneumocystis jirovecii Pneumonia Outbreak1. Emerg Infect Dis 2018; 23:1237-1245. [PMID: 28726611 PMCID: PMC5547796 DOI: 10.3201/eid2308.161295] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Pneumocystis jirovecii is a major threat for immunocompromised patients, and clusters of pneumocystis pneumonia (PCP) have been increasingly described in transplant units during the past decade. Exploring an outbreak transmission network requires complementary spatiotemporal and strain-typing approaches. We analyzed a PCP outbreak and demonstrated the added value of next-generation sequencing (NGS) for the multilocus sequence typing (MLST) study of P. jirovecii strains. Thirty-two PCP patients were included. Among the 12 solid organ transplant patients, 5 shared a major and unique genotype that was also found as a minor strain in a sixth patient. A transmission map analysis strengthened the suspicion of nosocomial acquisition of this strain for the 6 patients. NGS-MLST enables accurate determination of subpopulation, which allowed excluding other patients from the transmission network. NGS-MLST genotyping approach was essential to deciphering this outbreak. This innovative approach brings new insights for future epidemiologic studies on this uncultivable opportunistic fungus.
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26
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Functional and Expression Analyses of the Pneumocystis MAT Genes Suggest Obligate Sexuality through Primary Homothallism within Host Lungs. mBio 2018; 9:mBio.02201-17. [PMID: 29463658 PMCID: PMC5821091 DOI: 10.1128/mbio.02201-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Fungi of the genus Pneumocystis are obligate parasites that colonize mammals’ lungs and are host species specific. Pneumocystis jirovecii and Pneumocystis carinii infect, respectively, humans and rats. They can turn into opportunistic pathogens in immunosuppressed hosts, causing severe pneumonia. Their cell cycle is poorly known, mainly because of the absence of an established method of culture in vitro. It is thought to include both asexual and sexual phases. Comparative genomic analysis suggested that their mode of sexual reproduction is primary homothallism involving a single mating type (MAT) locus encompassing plus and minus genes (matMc, matMi, and matPi; Almeida et al., mBio 6:e02250-14, 2015). Thus, each strain would be capable of sexual reproduction alone (self-fertility). However, this is a working hypothesis derived from computational analyses that is, in addition, based on the genome sequences of single isolates. Here, we tested this hypothesis in the wet laboratory. The function of the P. jirovecii and P. carinii matMc genes was ascertained by restoration of sporulation in the corresponding mutant of fission yeast. Using PCR, we found the same single MAT locus in all P. jirovecii isolates and showed that all three MAT genes are often concomitantly expressed during pneumonia. Extensive homology searches did not identify other types of MAT transcription factors in the genomes or cis-acting motifs flanking the MAT locus that could have been involved in MAT switching or silencing. Our observations suggest that Pneumocystis sexuality through primary homothallism is obligate within host lungs to complete the cell cycle, i.e., produce asci necessary for airborne transmission to new hosts. Fungi of the genus Pneumocystis colonize the lungs of mammals. In immunosuppressed human hosts, Pneumocystis jirovecii may cause severe pneumonia that can be fatal. This disease is one of the most frequent life-threatening invasive fungal infections in humans. The analysis of the genome sequences of these uncultivable pathogens suggested that their sexual reproduction involves a single partner (self-fertilization). Here, we report laboratory experiments that support this hypothesis. The function of the three genes responsible for sexual differentiation was ascertained by the restoration of sexual reproduction in the corresponding mutant of another fungus. As predicted by self-fertilization, all P. jirovecii isolates harbored the same three genes that were often concomitantly expressed within human lungs during infection. Our observations suggest that the sexuality of these pathogens relies on the self-fertility of each isolate and is obligate within host lungs to complete the cell cycle and allow dissemination of the fungus to new hosts.
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27
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Cordonnier C, Alanio A, Cesaro S, Maschmeyer G, Einsele H, Donnelly JP, Hauser PM, Lagrou K, Melchers WJG, Helweg-Larsen J, Matos O, Bretagne S, Maertens J. Pneumocystis jirovecii pneumonia: still a concern in patients with haematological malignancies and stem cell transplant recipients-authors' response. J Antimicrob Chemother 2018; 72:1266-1268. [PMID: 28122911 DOI: 10.1093/jac/dkw580] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Catherine Cordonnier
- Department of Haematology, Henri Mondor Teaching Hospital, Assistance Publique-hôpitaux de Paris, and Université Paris-Est-Créteil, Créteil, France
| | - Alexandre Alanio
- Parasitology-Mycology Laboratory, Groupe Hospitalier Lariboisière Saint-Louis Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université Paris-Diderot, Sorbonne Paris Cité, and Institut Pasteur, Unité de Mycologie Moléculaire, CNRS URA3012, Centre National de Référence Mycoses Invasives et Antifongiques, Paris, France
| | - Simone Cesaro
- Department of Haematology, Oncoematologia Pediatrica, Policlinico G. B. Rossi, Verona, Italy
| | - Georg Maschmeyer
- Department of Haematology, Oncology and Palliative Care, Ernst-von-Bergmann Klinikum, Potsdam, Germany
| | - Hermann Einsele
- Department of Internal Medicine II, Julius Maximilians University, Würzburg, Germany
| | - J Peter Donnelly
- Department of Haematology Radboud University Medical Center, Nijmegen, The Netherlands
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital and University, Lausanne, Switzerland
| | - Katrien Lagrou
- Department of Microbiology and Immunology, KU Leuven?-?University of Leuven, Leuven, Belgium and National Reference Center for Mycosis, Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Willem J G Melchers
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jannik Helweg-Larsen
- Department of Infectious Diseases, Rigshospitalet-Copenhagen University Hospital, Copenhagen, Denmark
| | - Olga Matos
- Medical Parasitology Unit, Group of Opportunistic Protozoa/HIV and Other Protozoa, Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Stéphane Bretagne
- Parasitology-Mycology Laboratory, Groupe Hospitalier Lariboisière Saint-Louis Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université Paris-Diderot, Sorbonne Paris Cité, and Institut Pasteur, Unité de Mycologie Moléculaire, CNRS URA3012, Centre National de Référence Mycoses Invasives et Antifongiques, Paris, France
| | - Johan Maertens
- Department of Haematology, Acute Leukaemia and Stem Cell Transplantation Unit, University Hospitals Leuven, Campus Gasthuisberg, Leuven, Belgium
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Abstract
Microbial pathogens commonly escape the human immune system by varying surface proteins. We investigated the mechanisms used for that purpose by Pneumocystis jirovecii This uncultivable fungus is an obligate pulmonary pathogen that in immunocompromised individuals causes pneumonia, a major life-threatening infection. Long-read PacBio sequencing was used to assemble a core of subtelomeres of a single P. jirovecii strain from a bronchoalveolar lavage fluid specimen from a single patient. A total of 113 genes encoding surface proteins were identified, including 28 pseudogenes. These genes formed a subtelomeric gene superfamily, which included five families encoding adhesive glycosylphosphatidylinositol (GPI)-anchored glycoproteins and one family encoding excreted glycoproteins. Numerical analyses suggested that diversification of the glycoproteins relies on mosaic genes created by ectopic recombination and occurs only within each family. DNA motifs suggested that all genes are expressed independently, except those of the family encoding the most abundant surface glycoproteins, which are subject to mutually exclusive expression. PCR analyses showed that exchange of the expressed gene of the latter family occurs frequently, possibly favored by the location of the genes proximal to the telomere because this allows concomitant telomere exchange. Our observations suggest that (i) the P. jirovecii cell surface is made of a complex mixture of different surface proteins, with a majority of a single isoform of the most abundant glycoprotein, (ii) genetic mosaicism within each family ensures variation of the glycoproteins, and (iii) the strategy of the fungus consists of the continuous production of new subpopulations composed of cells that are antigenically different.IMPORTANCEPneumocystis jirovecii is a fungus causing severe pneumonia in immunocompromised individuals. It is the second most frequent life-threatening invasive fungal infection. We have studied the mechanisms of antigenic variation used by this pathogen to escape the human immune system, a strategy commonly used by pathogenic microorganisms. Using a new DNA sequencing technology generating long reads, we could characterize the highly repetitive gene families encoding the proteins that are present on the cellular surface of this pest. These gene families are localized in the regions close to the ends of all chromosomes, the subtelomeres. Such chromosomal localization was found to favor genetic recombinations between members of each gene family and to allow diversification of these proteins continuously over time. This pathogen seems to use a strategy of antigenic variation consisting of the continuous production of new subpopulations composed of cells that are antigenically different. Such a strategy is unique among human pathogens.
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Investigating Clinical Issues by Genotyping of Medically Important Fungi: Why and How? Clin Microbiol Rev 2017; 30:671-707. [PMID: 28490578 DOI: 10.1128/cmr.00043-16] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genotyping studies of medically important fungi have addressed elucidation of outbreaks, nosocomial transmissions, infection routes, and genotype-phenotype correlations, of which secondary resistance has been most intensively investigated. Two methods have emerged because of their high discriminatory power and reproducibility: multilocus sequence typing (MLST) and microsatellite length polymorphism (MLP) using short tandem repeat (STR) markers. MLST relies on single-nucleotide polymorphisms within the coding regions of housekeeping genes. STR polymorphisms are based on the number of repeats of short DNA fragments, mostly outside coding regions, and thus are expected to be more polymorphic and more rapidly evolving than MLST markers. There is no consensus on a universal typing system. Either one or both of these approaches are now available for Candida spp., Aspergillus spp., Fusarium spp., Scedosporium spp., Cryptococcus neoformans, Pneumocystis jirovecii, and endemic mycoses. The choice of the method and the number of loci to be tested depend on the clinical question being addressed. Next-generation sequencing is becoming the most appropriate method for fungi with no MLP or MLST typing available. Whatever the molecular tool used, collection of clinical data (e.g., time of hospitalization and sharing of similar rooms) is mandatory for investigating outbreaks and nosocomial transmission.
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30
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Alanio A, Gits-Muselli M, Guigue N, Desnos-Ollivier M, Calderon EJ, Di Cave D, Dupont D, Hamprecht A, Hauser PM, Helweg-Larsen J, Kicia M, Lagrou K, Lengerova M, Matos O, Melchers WJG, Morio F, Nevez G, Totet A, White LP, Bretagne S. Diversity of Pneumocystis jirovecii Across Europe: A Multicentre Observational Study. EBioMedicine 2017; 22:155-163. [PMID: 28705464 PMCID: PMC5552205 DOI: 10.1016/j.ebiom.2017.06.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/13/2017] [Accepted: 06/28/2017] [Indexed: 12/30/2022] Open
Abstract
Pneumocystis jirovecii is an airborne human-specific ascomycetous fungus responsible for Pneumocystis pneumonia (PCP) in immunocompromised patients, affecting >500,000 patients per year (www.gaffi.org). The understanding of its epidemiology is limited by the lack of standardised culture. Recent genotyping data suggests a limited genetic diversity of P. jirovecii. The objective of the study was to assess the diversity of P. jirovecii across European hospitals and analyse P. jirovecii diversity in respect to clinical data obtained from the patients. Genotyping was performed using six already validated short tandem repeat (STR) markers on 249 samples (median: 17 per centre interquartile range [11-20]) from PCP patients of 16 European centres. Mixtures of STR markers (i.e., ≥2 alleles for ≥1 locus) were detected in 67.6% (interquartile range [61.4; 76.5]) of the samples. Mixture was significantly associated with the underlying disease of the patient, with an increased proportion in HIV patients (78.3%) and a decreased proportion in renal transplant recipients (33.3%) (p<0.001). The distribution of the alleles was significantly different (p<0.001) according to the centres in three out of six markers. In analysable samples, 201 combinations were observed corresponding to 137 genotypes: 116 genotypes were country-specific; 12 in two; six in three; and two in four and one in five countries. Nine genotypes were recorded more than once in a given country. Genotype 123 (Gt123) was significantly associated with France (14/15, p<0.001) and Gt16 with Belgium (5/5, p<0.001). More specifically, Gt123 was observed mainly in France (14/15/16 patients) and in renal transplant patient (13/15). Our study showed the wide population diversity across Europe, with evidence of local clusters of patients harbouring a given genotype. These data suggest a specific association between genotype and underlying disease, with evidence of a different natural history of PCP in HIV patients and renal transplant recipients.
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Affiliation(s)
- Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie, AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Pasteur, CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, URA3012, Paris, France.
| | - Maud Gits-Muselli
- Laboratoire de Parasitologie-Mycologie, AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Nicolas Guigue
- Laboratoire de Parasitologie-Mycologie, AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France
| | - Marie Desnos-Ollivier
- Institut Pasteur, CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, URA3012, Paris, France
| | - Enrique J Calderon
- CIBER de Epidemiología y Salud Pública, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Spain
| | - David Di Cave
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Italy
| | - Damien Dupont
- Hospices Civils de Lyon, Institut des Agents Infectieux, Parasitologie Mycologie, Hôpital de la Croix-Rousse, Integrative Physiology of the Brain Arousal Systems, Centre de Recherche en Neurosciences de Lyon, INSERM U1028-CNRS UMR 5292, Faculté de Médecine, Université Claude Bernard Lyon 1, Lyon F-69000, France
| | - Axel Hamprecht
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Germany
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Jannik Helweg-Larsen
- Department of Infectious Diseases, Rigshospitalet-Copenhagen University Hospital, Copenhagen, Denmark
| | - Marta Kicia
- Department of Biology & Medical Parasitology, Wroclaw Medical University, Wroclaw, Poland
| | - Katrien Lagrou
- Department of Microbiology and Immunology, Catholic University Leuven, Leuven, Belgium and National Reference Centre for Mycosis, Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Martina Lengerova
- Department of Internal Medicine - Hematology and Oncology, University Hospital Brno, Brno, Czech Republic
| | - Olga Matos
- TB, HIV and Opportunistic Diseases and Pathogens, Global Health and Tropical Medicine, Lisboa, Portugal; Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Willem J G Melchers
- Department of medical microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Florent Morio
- Parasitology and Mycology laboratory, Nantes University Hospital, Nantes, France
| | - Gilles Nevez
- University of Brest, GEIHP EA 3142, Laboratory of Parasitology and Mycology, Brest University Hospital, Brest, France
| | - Anne Totet
- University of Picardy-Jules Verne, EA 4285 UMR-I 01 INERIS, Department of Parasitology and Mycology, Amiens University Hospital, Amiens, France
| | - Lewis P White
- Public Health Wales, Microbiology Cardiff, UHW, Heath Park, Cardiff, UK
| | - Stéphane Bretagne
- Laboratoire de Parasitologie-Mycologie, AP-HP, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut Pasteur, CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, URA3012, Paris, France
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Abstract
Pneumocystis jirovecii is an unusual ascomycetous fungus that can be detected in the lungs of healthy individuals. Transmission from human to human is one of its main characteristics in comparison with other fungi responsible for invasive infections.
P. jirovecii is transmitted through the air between healthy individuals, who are considered to be the natural reservoir, at least transiently. In immunocompromised patients,
P. jirovecii multiplies, leading to subacute infections and acute life-threatening pneumonia, called Pneumocystis pneumonia [PCP]. PCP is caused by genotypically distinct mixtures of organisms in more than 90% of cases, reinforcing the hypothesis that there is constant inhalation of
P. jirovecii from different contacts over time, although reactivation of latent organisms from previous exposures may be possible. Detection of
P. jirovecii DNA without any symptoms or related radiological signs has been called “colonization”. This situation could be considered as the result of recent exposure to
P. jirovecii that could evolve towards PCP, raising the issue of cotrimoxazole prophylaxis for at-risk quantitative polymerase chain reaction (qPCR)-positive immunocompromised patients. The more accurate way to diagnose PCP is the use of real-time quantitative PCR, which prevents amplicon contamination and allows determination of the fungal load that is mandatory to interpret the qPCR results and manage the patient appropriately. The detection of
P. jirovecii in respiratory samples of immunocompromised patients should be considered for potential risk of developing PCP. Many challenges still need to be addressed, including a better description of transmission, characterization of organisms present at low level, and prevention of environmental exposure during immunodepression.
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Affiliation(s)
- Alexandre Alanio
- Parasitology-Mycology Laboratory, Lariboisière Saint-Louis Fernand Widal Hospitals, Assistance Publique-Hôpitaux de Paris, Paris, France.,Paris-Diderot, Sorbonne Paris Cité University, Paris, France.,Molecular Mycology Unit, CNRS, Institut Pasteur, URA 3012, Paris, France
| | - Stéphane Bretagne
- Parasitology-Mycology Laboratory, Lariboisière Saint-Louis Fernand Widal Hospitals, Assistance Publique-Hôpitaux de Paris, Paris, France.,Paris-Diderot, Sorbonne Paris Cité University, Paris, France.,Molecular Mycology Unit, CNRS, Institut Pasteur, URA 3012, Paris, France
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Robin C, Alanio A, Gits-Muselli M, la Martire G, Schlemmer F, Botterel F, Angebault C, Leclerc M, Beckerich F, Redjoul R, Pautas C, Toma A, Maury S, Bretagne S, Cordonnier C. Molecular Demonstration of a Pneumocystis Outbreak in Stem Cell Transplant Patients: Evidence for Transmission in the Daycare Center. Front Microbiol 2017; 8:700. [PMID: 28484441 PMCID: PMC5401873 DOI: 10.3389/fmicb.2017.00700] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/05/2017] [Indexed: 12/24/2022] Open
Abstract
Pneumocystis jirovecii pneumonia (PCP) is a life-threatening infection in hematology. Although occasionally reported, the role of interhuman transmission of P. jirovecii in PCP, compared to that of reactivation, remains an unresolved question; the recommendation to isolate PCP patients in the hematology ward are not well evidence-based. Following an unexpected increase in the number of febrile pneumonia patients with P. jirovecii DNA detected in respiratory samples in our hematology ward, we explored 12 consecutive patients from November 2015 to May 2016. Genotyping of P jirovecii was performed using microsatellite markers. The frequency of simultaneous occupancy of these 12 patients in the same unit on the same day from 4 months prior to the first diagnosis was recorded. In three patients, the P. jirovecii genotype could not be determined because DNA was insufficient. One rare single genotype (Gt2) was found in four of the other nine, all allogeneic stem cell transplant recipients. The transmission map showed that these 4 patients had multiple opportunities to meet on the same day (median, 6.5; range, 4-10) at the daycare center. It was much less among the eight non-Gt2 patients (median, 1; range, 0-9; P = 0.048). This study, based on modern molecular technics, strongly suggests that interhuman transmission of P. jirovecii between allogeneic stem cell transplant recipients is possible. P. jirovecii DNA detected in respiratory specimens supports that isolation and respiratory precautions be recommended in such cases in the hematology ward.
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Affiliation(s)
- Christine Robin
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
| | - Alexandre Alanio
- Parasitology-Mycology Laboratory, Assistance Publique-Hôpitaux de Paris, Lariboisière Saint-Louis Fernand Widal HospitalParis, France
- Paris-Diderot, Sorbonne Paris Cité UniversityParis, France
- Molecular Mycology Unit, National Reference Center of Invasive Mycosis and Antifungals, Centre National de la Recherche Scientifique, Institut Pasteur, URA3012Paris, France
| | - Maud Gits-Muselli
- Parasitology-Mycology Laboratory, Assistance Publique-Hôpitaux de Paris, Lariboisière Saint-Louis Fernand Widal HospitalParis, France
- Paris-Diderot, Sorbonne Paris Cité UniversityParis, France
| | - Giulia la Martire
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
| | - Frédéric Schlemmer
- Paris-Est Créteil UniversityCréteil, France
- Unit of Pneumology, Intensive Care Department, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching Hospital, DHU A-TVBCréteil, France
| | - Françoise Botterel
- Paris-Est Créteil UniversityCréteil, France
- Parasitology-Mycology Laboratory, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
| | - Cécile Angebault
- Paris-Est Créteil UniversityCréteil, France
- Parasitology-Mycology Laboratory, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
| | - Mathieu Leclerc
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
| | - Florence Beckerich
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
| | - Rabah Redjoul
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
| | - Cécile Pautas
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
| | - Andrea Toma
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
| | - Sébastien Maury
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
| | - Stéphane Bretagne
- Parasitology-Mycology Laboratory, Assistance Publique-Hôpitaux de Paris, Lariboisière Saint-Louis Fernand Widal HospitalParis, France
- Paris-Diderot, Sorbonne Paris Cité UniversityParis, France
- Molecular Mycology Unit, National Reference Center of Invasive Mycosis and Antifungals, Centre National de la Recherche Scientifique, Institut Pasteur, URA3012Paris, France
| | - Catherine Cordonnier
- Department of Hematology, Assistance Publique-Hôpitaux de Paris, Henri Mondor Teaching HospitalCréteil, France
- Paris-Est Créteil UniversityCréteil, France
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Valero C, Buitrago MJ, Gits-Muselli M, Benazra M, Sturny-Leclère A, Hamane S, Guigue N, Bretagne S, Alanio A. Copy Number Variation of Mitochondrial DNA Genes in Pneumocystis jirovecii According to the Fungal Load in BAL Specimens. Front Microbiol 2016; 7:1413. [PMID: 27672381 PMCID: PMC5018473 DOI: 10.3389/fmicb.2016.01413] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 08/25/2016] [Indexed: 01/09/2023] Open
Abstract
Pneumocystis jirovecii is an unculturable fungus and the causative agent of Pneumocystis pneumonia, a life-threatening opportunistic infection. Although molecular diagnosis is often based on the detection of mtLSU rRNA mitochondrial gene, the number of copies of mitochondrial genes had not been investigated. We developed and optimized six real-time PCR assays in order to determine the copy number of four mitochondrial genes (mtSSU rRNA, mtLSU rRNA, NAD1, and CYTB) in comparison to nuclear genome (DHPS and HSP70) and tested 84 bronchoalveolar fluids of patients at different stages of the infection. Unexpectedly, we found that copy number of mitochondrial genes varied from gene to gene with mtSSU rRNA gene being more represented (37 copies) than NAD1 (23 copies), mtLSU rRNA (15 copies) and CYTB (6 copies) genes compared to nuclear genome. Hierarchical clustering analysis (HCA) allowed us to define five major clusters, significantly associated with fungal load (p = 0.029), in which copy number of mitochondrial genes was significantly different among them. More importantly, copy number of mtLSU rRNA, NAD1, and CYTB but not mtSSU rRNA differed according to P. jirovecii physiological state with a decreased number of copies when the fungal load is low. This suggests the existence of a mixture of various subspecies of mtDNA that can harbor different amplification rates. Overall, we revealed here an unexpected variability of P. jirovecii mtDNA copy number that fluctuates according to P. jirovecii’s physiological state, except for mtSSU that is the most stable and the most present mitochondrial gene.
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Affiliation(s)
- Clara Valero
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - María José Buitrago
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Maud Gits-Muselli
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique - Hôpitaux de ParisParis, France; Sorbonne Paris Cité, Université Paris DiderotParis, France
| | - Marion Benazra
- Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, Institut Pasteur Paris, France
| | - Aude Sturny-Leclère
- Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, Institut Pasteur Paris, France
| | - Samia Hamane
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique - Hôpitaux de Paris Paris, France
| | - Nicolas Guigue
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique - Hôpitaux de Paris Paris, France
| | - Stéphane Bretagne
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique - Hôpitaux de ParisParis, France; Sorbonne Paris Cité, Université Paris DiderotParis, France; Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, Institut PasteurParis, France; CNRS URA3012Paris, France
| | - Alexandre Alanio
- Laboratoire de Parasitologie-Mycologie, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique - Hôpitaux de ParisParis, France; Sorbonne Paris Cité, Université Paris DiderotParis, France; Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses Invasives et Antifongiques, Institut PasteurParis, France; CNRS URA3012Paris, France
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