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Tsvetkova N, Harizanov R, Rainova I, Ivanova A, Yancheva-Petrova N. Molecular Analysis of Dihydropteroate Synthase Gene Mutations in Pneumocystis jirovecii Isolates among Bulgarian Patients with Pneumocystis Pneumonia. Int J Mol Sci 2023; 24:16927. [PMID: 38069248 PMCID: PMC10707730 DOI: 10.3390/ijms242316927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Pneumocystis jirovecii pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the DHPS gene. This study aims to investigate the presence of DHPS gene mutations among P. jirovecii isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the P. jirovecii mitochondrial large subunit rRNA gene and further at the DHPS locus. P. jirovecii DNA was detected in 50 (15.34%) specimens. A 370 bp DHPS locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all (n = 21) P. jirovecii isolates showed DHPS genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by P. jirovecii mutants potentially resistant to sulfonamides are still rare events in Bulgaria. DHPS genotype 1 at codons 55 and 57 is the predominant P. jirovecii strain in the country.
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Affiliation(s)
- Nina Tsvetkova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Rumen Harizanov
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Iskra Rainova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Aleksandra Ivanova
- Department of Parasitology and Tropical Medicine, National Centre of Infectious and Parasitic Diseases, 26 Yanko Sakazov Blvd., 1504 Sofia, Bulgaria
| | - Nina Yancheva-Petrova
- Department for AIDS, Specialized Hospital for Active Treatment of Infectious and Parasitic Diseases, Ivan Geshev Blvd. 17, 1431 Sofia, Bulgaria
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Duysak T, Jeong JH, Kim K, Kim JS, Choy HE. Analysis of random mutations in Salmonella Gallinarum dihydropteroate synthase conferring sulfonamide resistance. Arch Microbiol 2023; 205:363. [PMID: 37906281 DOI: 10.1007/s00203-023-03696-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/26/2023] [Accepted: 09/29/2023] [Indexed: 11/02/2023]
Abstract
In bacteria and primitive eukaryotes, sulfonamide antibiotics block the folate pathway by inhibiting dihydropteroate synthase (FolP) that combines para-aminobenzoic acid (pABA) and dihydropterin pyrophosphate (DHPP) to form dihydropteroic acid (DHP), a precursor for tetrahydrofolate synthesis. However, the emergence of resistant strains has severely compromised the use of pABA mimetics as sulfonamide drugs. Salmonella enterica serovar Gallinarum (S. Gallinarum) is a significant source of antibiotic-resistant infections in poultry. Here, a sulfonamide-resistant FolP mutant library of S. Gallinarum was generated through random mutagenesis. Among resistant strains, substitution of amino acid Arginine 171 with Proline (R171P) in the FolP protein conferred the highest resistance against sulfonamide. Substitution of Phe28 with Leu or Ile (F28L/I) led to modest sulfonamide resistance. Structural modeling indicates that R171P and Phenylalanine 28 with leucine or isoleucine (F28L/I) substitution mutations are located far from the substrate-binding site and cause insignificant conformational changes in the FolP protein. Rather, in silico studies suggest that the mutations altered the stability of the protein, potentially resulting in sulfonamide resistance. Identification of specific mutations in FolP that confer resistance to sulfonamide would contribute to our understanding of the molecular mechanisms of antibiotic resistance.
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Affiliation(s)
- Taner Duysak
- Department of Microbiology, Chonnam National University Medical School, Gwangju, 61468, Korea
- Basic Medical Research Building, Odysseus Bio, Chonnam National University Medical College, 322 Seoyang-ro, Hwasun, 58128, Jeonnam, Korea
| | - Jae-Ho Jeong
- Department of Microbiology, Chonnam National University Medical School, Gwangju, 61468, Korea
| | - Kwangsoo Kim
- Basic Medical Research Building, Odysseus Bio, Chonnam National University Medical College, 322 Seoyang-ro, Hwasun, 58128, Jeonnam, Korea
| | - Jeong-Sun Kim
- Department of Chemistry, Chonnam National University, Gwangju, 61186, Korea.
| | - Hyon E Choy
- Department of Microbiology, Chonnam National University Medical School, Gwangju, 61468, Korea.
- Basic Medical Research Building, Odysseus Bio, Chonnam National University Medical College, 322 Seoyang-ro, Hwasun, 58128, Jeonnam, Korea.
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Rogers TR, Verweij PE, Castanheira M, Dannaoui E, White PL, Arendrup MC. OUP accepted manuscript. J Antimicrob Chemother 2022; 77:2053-2073. [PMID: 35703391 PMCID: PMC9333407 DOI: 10.1093/jac/dkac161] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The increasing incidence and changing epidemiology of invasive fungal infections continue to present many challenges to their effective management. The repertoire of antifungal drugs available for treatment is still limited although there are new antifungals on the horizon. Successful treatment of invasive mycoses is dependent on a mix of pathogen-, host- and antifungal drug-related factors. Laboratories need to be adept at detection of fungal pathogens in clinical samples in order to effectively guide treatment by identifying isolates with acquired drug resistance. While there are international guidelines on how to conduct in vitro antifungal susceptibility testing, these are not performed as widely as for bacterial pathogens. Furthermore, fungi generally are recovered in cultures more slowly than bacteria, and often cannot be cultured in the laboratory. Therefore, non-culture-based methods, including molecular tests, to detect fungi in clinical specimens are increasingly important in patient management and are becoming more reliable as technology improves. Molecular methods can also be used for detection of target gene mutations or other mechanisms that predict antifungal drug resistance. This review addresses acquired antifungal drug resistance in the principal human fungal pathogens and describes known resistance mechanisms and what in-house and commercial tools are available for their detection. It is emphasized that this approach should be complementary to culture-based susceptibility testing, given the range of mutations, resistance mechanisms and target genes that may be present in clinical isolates, but may not be included in current molecular assays.
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Affiliation(s)
| | | | | | | | | | - Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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de la Horra C, Friaza V, Morilla R, Delgado J, Medrano FJ, Miller RF, de Armas Y, Calderón EJ. Update on Dihydropteroate Synthase (DHPS) Mutations in Pneumocystis jirovecii. J Fungi (Basel) 2021; 7:jof7100856. [PMID: 34682277 PMCID: PMC8540849 DOI: 10.3390/jof7100856] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/28/2021] [Accepted: 10/10/2021] [Indexed: 12/21/2022] Open
Abstract
A Pneumocystis jirovecii is one of the most important microorganisms that cause pneumonia in immunosupressed individuals. The guideline for treatment and prophylaxis of Pneumocystis pneumonia (PcP) is the use of a combination of sulfa drug-containing trimethroprim and sulfamethoxazole. In the absence of a reliable method to culture Pneumocystis, molecular techniques have been developed to detect mutations in the dihydropteroate synthase gene, the target of sulfa drugs, where mutations are related to sulfa resistance in other microorganisms. The presence of dihydropteroate synthase (DHPS) mutations has been described at codon 55 and 57 and found almost around the world. In the current work, we analyzed the most common methods to identify these mutations, their geographical distribution around the world, and their clinical implications. In addition, we describe new emerging DHPS mutations. Other aspects, such as the possibility of transmitting Pneumocystis mutated organisms between susceptible patients is also described, as well as a brief summary of approaches to study these mutations in a heterologous expression system.
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Affiliation(s)
- 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; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
| | - Vicente Friaza
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
- Correspondence: (V.F.); (E.J.C.); Tel.: +34-955923096 (E.J.C.)
| | - Rubén Morilla
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
- Departamento de Enfermería, Universidad de Sevilla, 41009 Seville, Spain
| | - Juan Delgado
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
| | - Francisco J. Medrano
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
- Departamento de Medicina, Universidad de Sevilla, 41009 Seville, Spain
| | - Robert F. Miller
- Institute for Global Health, University College London, London WC1E 6JB, UK;
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Yaxsier de Armas
- Department of Clinical Microbiology Diagnostic, Hospital Center of Institute of Tropical Medicine “Pedro Kourí”, Havana 11400, Cuba;
- Pathology Department, Hospital Center of Institute of Tropical Medicine “Pedro Kourí,” Havana 11400, Cuba
| | - Enrique J. Calderón
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Seville, Spain; (C.d.l.H.); (R.M.); (J.D.); (F.J.M.)
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
- Departamento de Medicina, Universidad de Sevilla, 41009 Seville, Spain
- Correspondence: (V.F.); (E.J.C.); Tel.: +34-955923096 (E.J.C.)
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Singh Y, Mirdha BR, Guleria R, Kabra SK, Mohan A, Chaudhry R, Kumar L, Dwivedi SN, Agarwal SK. Genetic polymorphisms associated with treatment failure and mortality in pediatric Pneumocystosis. Sci Rep 2019; 9:1192. [PMID: 30718779 PMCID: PMC6361943 DOI: 10.1038/s41598-018-38052-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/19/2018] [Indexed: 12/15/2022] Open
Abstract
Data on the genetic diversity of Pneumocystis jirovecii causing Pneumocystis pneumonia (PCP) among children are still limited, and there are no available data from the Indian subcontinent, particularly associations between genotypes and clinical characteristics. A total of 37 children (62 days-12 years [median 5.5 years]) were included in this study. Pneumocystis was diagnosed by microscopy using Grocott-Gomori methenamine silver stain in 12 cases and by nested PCR using mtLSUrRNA in 25 cases. Genotyping was performed using three different genes, mitochondrial large subunit ribosomal RNA (mtLSUrRNA), dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR). mtLSUrRNA genotype 3 and novel mutations at the gene target DHFR (401 T > C) and DHPS 96/98 were frequently observed and clinically associated with severe PCP and treatment failure. Phylogenetic analyses revealed 13 unique sequence types (STs). Two STs (i) 3-DHFR 401 T > C-DHPS 96/98 – PJ1 and (ii) 3-DHFR 401 T > C-DHPS 96- PJ3 were significantly associated with treatment failure and high mortality among PCP-positive patients. In conclusion, the present study strongly suggests the emergence of virulent P. jirovecii strains or genetic polymorphisms, leading to treatment failure and high mortality. Our study is the first of its kind from the Indian subcontinent and has highlighted the genetic diversity of Pneumocystis jirovecii among children and their clinical outcomes. These findings emphasize the need to focus more on genotypes to better understand the epidemiology of Pneumocystis pneumonia.
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Affiliation(s)
- Yogita Singh
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi, 110029, India
| | - Bijay Ranjan Mirdha
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi, 110029, India.
| | - Randeep Guleria
- All India Institute of Medical Sciences, Department of Pulmonary Medicine and Sleep Disorders, New Delhi, 110029, India
| | - Sushil K Kabra
- All India Institute of Medical Sciences, Department of Pediatrics, New Delhi, 110029, India
| | - Anant Mohan
- All India Institute of Medical Sciences, Department of Pulmonary Medicine and Sleep Disorders, New Delhi, 110029, India
| | - Rama Chaudhry
- All India Institute of Medical Sciences, Department of Microbiology, New Delhi, 110029, India
| | - Lalit Kumar
- All India Institute of Medical Sciences, Department of Medical Oncology, New Delhi, 110029, India
| | - Sada Nand Dwivedi
- All India Institute of Medical Sciences, Department of Biostatistics, New Delhi, 110029, India
| | - Sanjay K Agarwal
- All India Institute of Medical Sciences, Department of Nephrology, New Delhi, 110029, India
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6
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Szydłowicz M, Jakuszko K, Szymczak A, Piesiak P, Kowal A, Kopacz Ż, Wesołowska M, Lobo ML, Matos O, Hendrich AB, Kicia M. Prevalence and genotyping of Pneumocystis jirovecii in renal transplant recipients-preliminary report. Parasitol Res 2018; 118:181-189. [PMID: 30392033 PMCID: PMC6329730 DOI: 10.1007/s00436-018-6131-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/23/2018] [Indexed: 12/24/2022]
Abstract
Pneumocystis jirovecii is an opportunistic fungus occurring in human lungs. The group at highest risk consists of HIV-infected and non-HIV-infected immunosuppressed individuals. In these patients, P. jirovecii infection may lead to Pneumocystis pneumonia; it may, however, persist also in an asymptomatic form. This study aimed to determine the prevalence of P. jirovecii and potential risk factors for infection in a group of renal transplant recipients and to characterize the genetic diversity of this fungus in the studied population. Sputum specimens from 72 patients were tested for presence of P. jirovecii using immunofluorescence microscopy, as well as nested PCR targeting the mtLSU rRNA gene. Genotyping involving analysis of four loci—mtLSU rRNA, CYB, DHPS, and SOD—was used to characterize the diversity of the detected organisms. Pneumocystis DNA was detected in eight (11.11%) patients. It has been shown that low eosinophil count and dual immunosuppressive treatment combining prednisone and calcineurin inhibitors are potential risk factors for colonization. Analysis of genotype distribution showed an association of the wild-type genotype of mtLSU rRNA with lower average age of patients and shorter time after kidney transplantation. Furthermore, CYB 2 genotype was detected only in patients with the ongoing prophylaxis regimen. In conclusion, renal transplant recipients are at risk of Pneumocystis colonization even a long time after transplantation. The present preliminary study identifies specific polymorphisms that appear to be correlated with certain patient characteristics and highlights the need for deeper investigation of these associations in renal transplant recipients.
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Affiliation(s)
- Magdalena Szydłowicz
- Department of Biology and Medical Parasitology, Wroclaw Medical University, ul. J. Mikulicza-Radeckiego 9, 50-345, Wroclaw, Poland.
| | - Katarzyna Jakuszko
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Anna Szymczak
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Paweł Piesiak
- Department of Pulmonology and Lung Cancer, Wroclaw Medical University, Wroclaw, Poland
| | - Aneta Kowal
- Department of Pulmonology and Lung Cancer, Wroclaw Medical University, Wroclaw, Poland
| | - Żaneta Kopacz
- Department of Biology and Medical Parasitology, Wroclaw Medical University, ul. J. Mikulicza-Radeckiego 9, 50-345, Wroclaw, Poland
| | - Maria Wesołowska
- Department of Biology and Medical Parasitology, Wroclaw Medical University, ul. J. Mikulicza-Radeckiego 9, 50-345, Wroclaw, Poland
| | - Maria Luísa Lobo
- Global Health and Tropical Medicine, Unit of Medical Parasitology, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Olga Matos
- Global Health and Tropical Medicine, Unit of Medical Parasitology, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Andrzej B Hendrich
- Department of Biology and Medical Parasitology, Wroclaw Medical University, ul. J. Mikulicza-Radeckiego 9, 50-345, Wroclaw, Poland
| | - Marta Kicia
- Department of Biology and Medical Parasitology, Wroclaw Medical University, ul. J. Mikulicza-Radeckiego 9, 50-345, Wroclaw, Poland
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Griffith EC, Wallace MJ, Wu Y, Kumar G, Gajewski S, Jackson P, Phelps GA, Zheng Z, Rock CO, Lee RE, White SW. The Structural and Functional Basis for Recurring Sulfa Drug Resistance Mutations in Staphylococcus aureus Dihydropteroate Synthase. Front Microbiol 2018; 9:1369. [PMID: 30065703 PMCID: PMC6057106 DOI: 10.3389/fmicb.2018.01369] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Staphylococcal species are a leading cause of bacterial drug-resistant infections and associated mortality. One strategy to combat bacterial drug resistance is to revisit compromised targets, and to circumvent resistance mechanisms using structure-assisted drug discovery. The folate pathway is an ideal candidate for this approach. Antifolates target an essential metabolic pathway, and the necessary detailed structural information is now available for most enzymes in this pathway. Dihydropteroate synthase (DHPS) is the target of the sulfonamide class of drugs, and its well characterized mechanism facilitates detailed analyses of how drug resistance has evolved. Here, we surveyed clinical genetic sequencing data in S. aureus to distinguish natural amino acid variations in DHPS from those that are associated with sulfonamide resistance. Five mutations were identified, F17L, S18L, T51M, E208K, and KE257_dup. Their contribution to resistance and their cost to the catalytic properties of DHPS were evaluated using a combination of biochemical, biophysical and microbiological susceptibility studies. These studies show that F17L, S18L, and T51M directly lead to sulfonamide resistance while unexpectedly increasing susceptibility to trimethoprim, which targets the downstream enzyme dihydrofolate reductase. The secondary mutations E208K and KE257_dup restore trimethoprim susceptibility closer to wild-type levels while further increasing sulfonamide resistance. Structural studies reveal that these mutations appear to selectively disfavor the binding of the sulfonamides by sterically blocking an outer ring moiety that is not present in the substrate. This emphasizes that new inhibitors must be designed that strictly stay within the substrate volume in the context of the transition state.
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Affiliation(s)
- Elizabeth C. Griffith
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Miranda J. Wallace
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, United States
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Yinan Wu
- Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Gyanendra Kumar
- Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Stefan Gajewski
- Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Pamela Jackson
- Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Gregory A. Phelps
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, United States
- Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Zhong Zheng
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Charles O. Rock
- Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Richard E. Lee
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Stephen W. White
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
- Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
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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: 41] [Impact Index Per Article: 6.8] [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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9
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Evaluation of a new commercial real-time PCR assay for diagnosis of Pneumocystis jirovecii pneumonia and identification of dihydropteroate synthase (DHPS) mutations. Diagn Microbiol Infect Dis 2016; 87:32-36. [PMID: 27789058 DOI: 10.1016/j.diagmicrobio.2016.10.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/22/2016] [Accepted: 10/04/2016] [Indexed: 12/14/2022]
Abstract
The PneumoGenius® real-time PCR assay is a new commercial multiplex real-time PCR method, which detects the Pneumocystis mitochondrial ribosomal large subunit (mtLSU) and two dihydropteroate synthase (DHPS) point mutations. To evaluate the clinical performance of this new real-time PCR assay we tested 120 extracted DNA samples from bronchoalveolar lavage specimens. These set of extracted DNA samples had already tested positive for Pneumocystis and patients had been classified in probable and unlikely PCP in a previous study. To evaluate de accuracy of the DHPS mutant's identification, an "in house" PCR and sequencing was performed. The sensitivity and specificity of PneumoGenius® PCR in discriminating between probable and unlikely Pneumocystis pneumonia (PCP) were 70% and 82% respectively. PneumoGenius® PCR was able to genotype more samples than "in house" DHPS PCR and sequencing. The same DHPS mutations were observed by both methods in four patients: two patients with a single mutation in position 171 (Pro57Ser) and two patients with a double mutation in position 165 (Thr55Ala) and in position 171 (Pro57Ser). A low rate of P. jirovecii (4.5%) harboring DHPS mutations was found, comparable to rates observed in other European countries. The PneumoGenius® real-time PCR is a suitable real-time PCR for PCP diagnosis and detection of DHPS mutants. The added value of DHPS mutation identification can assist in understanding the role of these mutations in prophylaxis failure or treatment outcome.
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Abstract
Few modern diseases have experienced as rapid and dramatic change in prognosis and treatment as HIV infection. The introduction of active antiretroviral therapy (ART) and effective prophylaxis of opportunistic infections ushered in a new era in the treatment of HIV infection and changed dramatically the natural history of this disease. The rates of admission to the intensive care unit (ICU) and intensive care mortality in patients with HIV infection have shifted repeatedly during the AIDS epidemic, influenced by attitudes of patients and providers toward utility of care. In the ART era, patients with HIV infection admitted to the ICU fall into 3 general categories: those with AIDS-related opportunistic infections, those who are experiencing complications related to ART, and those with medical problems unrelated to HIV infection. In this article, the authors provide a review of the most common life-threatening complications in patients with HIV infection.
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Affiliation(s)
- Raul E Davaro
- UMass Memorial Health Care, Worcester, MA 01605, USA.
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Esteves F, de Sousa B, Calderón E, Huang L, Badura R, Maltez F, Bassat Q, de Armas Y, Antunes F, Matos O. Multicentre study highlighting clinical relevance of new high-throughput methodologies in molecular epidemiology of Pneumocystis jirovecii pneumonia. Clin Microbiol Infect 2016; 22:566.e9-566.e19. [DOI: 10.1016/j.cmi.2016.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/19/2016] [Accepted: 03/13/2016] [Indexed: 11/17/2022]
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Alanio A, Hauser PM, Lagrou K, Melchers WJG, Helweg-Larsen J, Matos O, Cesaro S, Maschmeyer G, Einsele H, Donnelly JP, Cordonnier C, Maertens J, Bretagne S. ECIL guidelines for the diagnosis of Pneumocystis jirovecii pneumonia in patients with haematological malignancies and stem cell transplant recipients. J Antimicrob Chemother 2016; 71:2386-96. [PMID: 27550991 DOI: 10.1093/jac/dkw156] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The Fifth European Conference on Infections in Leukaemia (ECIL-5) convened a meeting to establish evidence-based recommendations for using tests to diagnose Pneumocystis jirovecii pneumonia (PCP) in adult patients with haematological malignancies. Immunofluorescence assays are recommended as the most sensitive microscopic method (recommendation A-II: ). Real-time PCR is recommended for the routine diagnosis of PCP ( A-II: ). Bronchoalveolar lavage (BAL) fluid is recommended as the best specimen as it yields good negative predictive value ( A-II: ). Non-invasive specimens can be suitable alternatives ( B-II: ), acknowledging that PCP cannot be ruled out in case of a negative PCR result ( A-II: ). Detecting β-d-glucan in serum can contribute to the diagnosis but not the follow-up of PCP ( A-II: ). A negative serum β-d-glucan result can exclude PCP in a patient at risk ( A-II: ), whereas a positive test result may indicate other fungal infections. Genotyping using multilocus sequence markers can be used to investigate suspected outbreaks ( A-II: ). The routine detection of dihydropteroate synthase mutations in cases of treatment failure is not recommended ( B-II: ) since these mutations do not affect response to high-dose co-trimoxazole. The clinical utility of these diagnostic tests for the early management of PCP should be further assessed in prospective, randomized interventional studies.
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Affiliation(s)
- 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
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Katrien Lagrou
- Department of Microbiology and Immunology, Catholic University 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, Portugal Universidade Nova de Lisboa, Lisboa, Portugal
| | - Simone Cesaro
- Hematology Department, Oncoematologia Pediatrica, Policlinico G. B. Rossi, Verona, Italy
| | - Georg Maschmeyer
- Department of Hematology, Oncology and Palliative Care, Ernst-von-Bergmann Klinikum, Potsdam, Germany
| | - Hermann Einsele
- Medizinische Klinik und Poliklinik II, Julius Maximilians Universitaet, Würzburg, Germany
| | - J Peter Donnelly
- Department of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Catherine Cordonnier
- Hematology Department, Henri Mondor Hospital, APHP and Université Paris-Est-Créteil, Créteil, France
| | - Johan Maertens
- Hematology Department, University Hospital Leuven, Campus Gasthuisberg, Leuven, Belgium
| | - 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
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Pneumocystis jirovecii--from a commensal to pathogen: clinical and diagnostic review. Parasitol Res 2015; 114:3577-85. [PMID: 26281787 PMCID: PMC4562001 DOI: 10.1007/s00436-015-4678-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 01/09/2023]
Abstract
Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of morbidity and mortality cases among HIV-infected patients, which later have been reduced due to the introduction of anti-retroviral therapy, as well as anti-Pneumocystis prophylaxis among these patients. Pneumocystis pneumonia, however, is still a significant cause of mortality among HIV-negative patients being under immunosuppression caused by different factors, such as transplant recipients as well as oncologically treated ones. The issue of pneumocystosis among these people is particularly emphasized in the article, since rapid onset and fast progression of severe symptoms result in high mortality rate among these patients, who thereby represent the group of highest risk of developing Pneumocystis pneumonia. In contrast, fungal invasion in immunocompetent people usually leads to asymptomatic colonization, which frequent incidence among healthy infants has even suggested the possibility of its association with sudden unexpected infant death syndrome. In the face of emerging strains with different epidemiological profiles resulting from genetic diversity, including drug-resistant genotypes, the colonization phenomenon desires particular attention, discussed in this article. We also summarize specific and sensitive methods, required for detection of Pneumocystis invasion and for distinguish colonization from the disease.
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Mogoye BK, Du Plessis D, Poonsamy B, Frean J. Characterisation of Pneumocystis jiroveciiDHPS genotypes using a simple, inexpensive restriction fragment length polymorphism analysis. S Afr J Infect Dis 2015. [DOI: 10.1080/23120053.2015.1054180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Lee SM, Cho YK, Sung YM, Chung DH, Jeong SH, Park JW, Lee SP. A Case of Pneumonia Caused by Pneumocystis jirovecii Resistant to Trimethoprim-Sulfamethoxazole. THE KOREAN JOURNAL OF PARASITOLOGY 2015; 53:321-7. [PMID: 26174826 PMCID: PMC4510680 DOI: 10.3347/kjp.2015.53.3.321] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 11/23/2022]
Abstract
A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.
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Affiliation(s)
- Sang Min Lee
- Division of Pulmonology and Allergy, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Yong Kyun Cho
- Division of Infection, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Yon Mi Sung
- Department of Radiology, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Dong Hae Chung
- Departement of Pathology, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Sung Hwan Jeong
- Division of Pulmonology and Allergy, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Jeong-Woong Park
- Division of Pulmonology and Allergy, Gachon University Gil Medical Center, Incheon 405-760, Korea
| | - Sang Pyo Lee
- Division of Pulmonology and Allergy, Gachon University Gil Medical Center, Incheon 405-760, Korea
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Friaza V, Morilla R, Respaldiza N, de la Horra C, Calderón EJ. Pneumocystis jiroveciDihydropteroate Synthase Gene Mutations among Colonized Individuals andPneumocystisPneumonia Patients from Spain. Postgrad Med 2015; 122:24-8. [DOI: 10.3810/pgm.2010.11.2219] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Sheikholeslami MF, Sadraei J, Farnia P, Forozandeh Moghadam M, Emadikochak H. Dihydropteroate synthase gene mutation rates in Pneumocystis jirovecii strains obtained from Iranian HIV-positive and non-HIV-positive patients. Med Mycol 2015; 53:361-8. [PMID: 25631478 DOI: 10.1093/mmy/myu095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/15/2014] [Indexed: 12/17/2022] Open
Abstract
The dihydropteroate sulfate (DHPS) gene is associated with resistance to sulfa/sulfone drugs in Pneumocystis jirovecii. We investigated the DHPS mutation rate in three groups of Iranian HIV-positive and HIV-negative patients by polymerase chain reaction-restricted fragment length polymorphism analysis. Furthermore, an association between P. jirovecii DHPS mutations and strain typing was investigated based on direct sequencing of internal transcribed spacer region 1 (ITS1) and ITS2. The overall P. jirovecii DHPS mutation rate was (5/34; 14.7%), the lowest rate identified was in HIV-positive patients (1/16; 6.25%) and the highest rate was in malignancies patients (3/11; 27.3%). A moderate rate of mutation was detected in chronic obstructive pulmonary disease (COPD) patients (1/7; 14.3%). Most of the isolates were wild type (29/34; 85.3%). Double mutations in DHPS were detected in patients with malignancies, whereas single mutations at codons 55 and 57 were identified in the HIV-positive and COPD patients, respectively. In this study, two new and rare haplotypes were identified with DHPS mutations. Additionally, a positive relationship between P. jirovecii strain genotypes and DHPS mutations was identified. In contrast, no DHPS mutations were detected in the predominant (Eg) haplotype. This should be regarded as a warning of an increasing incidence of drug-resistant P. jirovecii strains.
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Affiliation(s)
- Maryam-Fatemeh Sheikholeslami
- Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran Tarbiat Modares University, Medical Faculty, Parasitology Department, Tehran, Iran
| | - Javid Sadraei
- Tarbiat Modares University, Medical Faculty, Parasitology Department, Tehran, Iran
| | - Parisa Farnia
- Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Hamid Emadikochak
- Iranian HIV/AIDS Research Center, Imam Khomini Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Khodavaisy S, Mortaz E, Mohammadi F, Aliyali M, Fakhim H, Badali H. Pneumocystis jirovecii colonization in Chronic Obstructive Pulmonary Disease (COPD). Curr Med Mycol 2015; 1:42-48. [PMID: 28680980 PMCID: PMC5490321 DOI: 10.18869/acadpub.cmm.1.1.42] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is associated with a chronic inflammatory response in airways and lung parenchyma that results in significant morbidity and mortality worldwide. Cigarette smoking considered as an important risk factor plays a role in pathogenesis of disease. Pneumocystis jirovecii is an atypical opportunistic fungus that causes pneumonia in immunosuppressed host, although the low levels of its DNA in patients without signs and symptoms of pneumonia, which likely represents colonization. The increased prevalence of P. jirovecii colonization in COPD patients has led to an interest in understanding its role in the disease. P. jirovecii colonization in these patients could represent a problem for public health since colonized patients could act as a major reservoir and source of infection for susceptible subjects. Using sensitive molecular techniques, low levels of P. jirovecii DNA have been detected in the respiratory tract of certain individuals. It is necessary to elucidate the role of P. jirovecii colonization in the natural history of COPD patients in order to improve the clinical management of this disease. In the current review paper, we discuss P. jirovecii colonization in COPD patients.
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Affiliation(s)
- S Khodavaisy
- Department of Medical Parasitology and Mycology, Kurdistan University of Medical Sciences, Sanandaj, Iran.,Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - E Mortaz
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - F Mohammadi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - M Aliyali
- Pulmonary and Critical Care Division, Mazandaran University of Medical Sciences, Sari, Iran
| | - H Fakhim
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - H Badali
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Long Y, Zhang C, Su L, Que C. Pneumocystis jirovecii dihydropteroate synthase gene mutations in a group of HIV-negative immunocompromised patients with Pneumocystis pneumonia. Exp Ther Med 2014; 8:1825-1830. [PMID: 25371739 PMCID: PMC4218695 DOI: 10.3892/etm.2014.2002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 09/04/2014] [Indexed: 12/28/2022] Open
Abstract
The purpose of this study was to investigate dihydropteroate synthase (DHPS) mutations and their clinical context in non-HIV-infected patients with Pneumocystis pneumonia (PCP). DHPS genes in respiratory samples collected from HIV-negative patients with PCP presented between January 2008 and April 2011 were amplified by polymerase chain reaction (PCR) and sequenced. Basic clinical data from the medical records of the patients were also reviewed. The most common point mutations, which result in Thr55Ala and Pro57Ser amino acid substitutions, were not detected in the Pneumocystis jirovecii sampled from the HIV-negative patients. Two other point mutations, which result in nonsynonymous mutation, Asp90Asn and Glu98Lys, were identified in P. jirovecii from two patients. Among the patients, the levels of lactate dehydrogenase (LDH), C-reactive protein (CRP) and plasma (1-3) β-D-glucan were elevated in 75, 92.31 and 42.86% of patients, respectively. The percentage of circulating lymphocytes was significantly lower in non-survivors than in survivors [4.2%, interquartile range (IQR) 2.4-5.85 versus 10.1%, IQR 5.65-23.4; P=0.019]. The neutrophil proportion in bronchoalveolar lavage fluid (BALF) was significantly higher in non-survivors than in survivors (49.78±27.67 versus 21.33±15.03%; P=0.047). Thirteen patients had received adjunctive corticosteroids (1 mg/kg/day prednisone equivalent) and nine (69.23%) of them eventually experienced treatment failure. No common DHPS gene mutations of P. jirovecii were detected in the HIV-negative PCP patients. However, other mutations did exist, the significance of which remains to be further identified. The elevation of neutrophil counts in BALF and reduction of the number of lymphocytes in peripheral blood may be associated with poor outcome. The efficacy of adjunctive steroid therapy in HIV-negative patients with P. jirovecii infection requires further investigation.
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Affiliation(s)
- Yingjiao Long
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Cheng Zhang
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Li Su
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
| | - Chengli Que
- Department of Pulmonary Medicine, First Hospital, Peking University, Beijing 100034, P.R. China
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20
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Gray D, Zar HJ. Management of community-acquired pneumonia in HIV-infected children. Expert Rev Anti Infect Ther 2014; 7:437-51. [DOI: 10.1586/eri.09.14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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21
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Flegg JA, Metcalf CJE, Gharbi M, Venkatesan M, Shewchuk T, Hopkins Sibley C, Guerin PJ. Trends in antimalarial drug use in Africa. Am J Trop Med Hyg 2013; 89:857-865. [PMID: 24019436 PMCID: PMC3820326 DOI: 10.4269/ajtmh.13-0129] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Resistance to chloroquine (CQ) and sulphadoxine-pyrimethamine (SP) led the World Health Organization (WHO) to recommend changes in national drug policies. The time between policy changes and their implementation profoundly affects program impact. We developed a model based on data on antimalarial treatments, extracted from household surveys and national antimalarial policy information from the literature. Drug use in each country during the time period 1999–2011 and the trend in reduction of CQ use after policy change were estimated. The SP use estimates were correlated with the prevalence of a molecular marker associated with SP resistance. There was no spatial pattern in the country-level rate of reduction of CQ use, after policy change. In East Africa SP drug use was strongly correlated to resistance. If artemisinin resistance spreads to, or emerges in, Africa this methodology will be a valuable tool to estimate actual drug use and its impact on changes in drug efficacy.
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Affiliation(s)
- Jennifer A. Flegg
- *Address correspondence to Jennifer A. Flegg, Centre for Tropical Medicine, University of Oxford, CCVTM, Churchill Hospital, Old Road, Oxford, OX3 7LJ, UK. E-mail:
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Multilocus sequence typing of Pneumocystis jirovecii from clinical samples: how many and which loci should be used? J Clin Microbiol 2013; 51:2843-9. [PMID: 23784120 DOI: 10.1128/jcm.01073-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection with airborne transmission and remains a major cause of respiratory illness among immunocompromised individuals. In recent years, several outbreaks of PCP, occurring mostly in kidney transplant recipients, have been reported. Currently, multilocus sequence typing (MLST) performed on clinical samples is considered to be the gold standard for epidemiological investigations of nosocomial clusters of PCP. However, until now, no MLST consensus scheme has emerged. The aim of this study was to evaluate the discriminatory power of eight distinct loci previously used for the molecular typing of P. jirovecii (internal transcribed spacer 1 [ITS1], cytochrome b [CYB], mitochondrial rRNA gene [mt26S], large subunit of the rRNA gene [26S], superoxide dismutase [SOD], β-tubulin [β-TUB], dihydropteroate synthase [DHPS], and dihydrofolate reductase [DHFR]) using a cohort of 33 epidemiologically unrelated patients having respiratory samples that were positive for P. jirovecii and who were admitted to our hospital between 2006 and 2011. Our results highlight that the choice of loci for MLST is crucial, as the discriminatory power of the method was highly variable from locus to locus. In all, the eight-locus-based scheme we used displayed a high discriminatory power (Hunter [H] index, 0.996). Based on our findings, a simple and alternative MLST scheme relying on three loci only (mt26S, CYB, and SOD) provides enough discriminatory power (H-index, 0.987) to be used for preliminary investigations of nosocomial clusters of PCP.
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Rabodonirina M, Vaillant L, Taffé P, Nahimana A, Gillibert RP, Vanhems P, Hauser PM. Pneumocystis jirovecii genotype associated with increased death rate of HIV-infected patients with pneumonia. Emerg Infect Dis 2013; 19:21-8; quiz 186. [PMID: 23260763 PMCID: PMC3557975 DOI: 10.3201/eid1901.120140] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Comorbidities might predict presence of specific fungal genotypes.
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Yoon C, Subramanian A, Chi A, Crothers K, Meshnick SR, Taylor SM, Beard CB, Jarlsberg LG, Lawrence GG, Avery M, Swartzman A, Fong S, Roth B, Huang L. Dihydropteroate synthase mutations in Pneumocystis pneumonia: impact of applying different definitions of prophylaxis, mortality endpoints and mutant in a single cohort. Med Mycol 2013; 51:568-75. [PMID: 23470037 DOI: 10.3109/13693786.2013.770604] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations are well-reported. Although sulfa prophylaxis generally is associated with DHPS mutant infection, whether mutant infection is associated with poorer clinical outcomes is less clear. The differing definitions of sulfa prophylaxis and the different mortality endpoints used in these studies may be one explanation for the conflicting study results. Applying different definitions of prophylaxis, mortality endpoints and DHPS mutant to 301 HIV-infected patients with Pneumocystis pneumonia, we demonstrate that prophylaxis, irrespective of definition, increased the risk of infection with pure mutant (any prophylaxis: AOR 4.00, 95% CI: 1.83-8.76, P < 0.001) but not mixed genotypes (any prophylaxis: AOR 0.78, 95% CI: 0.26-2.36, P = 0.65). However, infection with mutant DHPS, irrespective of definition, was not associated with increased mortality (all-cause or PCP death) at the three time-intervals examined (all P > 0.05). Future studies should standardize key variables associated with DHPS mutant infection as well as examine DHPS mutant subtypes (pure mutant vs. mixed infections) - perhaps even individual DHPS mutant genotypes - so that data can be pooled to better address this issue.
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Affiliation(s)
- Christina Yoon
- San Francisco General Hospital, Division of Pulmonary & Critical Care Medicine, University of California, San Francisco, California 94110, USA.
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Le Gal S, Robert-Gangneux F, Perrot M, Rouillé A, Virmaux M, Damiani C, Totet A, Gangneux JP, Nevez G. Absence of Pneumocystis dihydropteroate synthase mutants in Brittany, France. Diagn Microbiol Infect Dis 2013; 76:113-5. [PMID: 23433532 DOI: 10.1016/j.diagmicrobio.2013.01.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/16/2013] [Accepted: 01/16/2013] [Indexed: 11/15/2022]
Abstract
Archival Pneumocystis jirovecii specimens from 84 patients monitored at Rennes University Hospital (Rennes, France) were assayed at the dihydropteroate synthase (DHPS) locus. No patient was infected with mutants. The results provide additional data showing that P. jirovecii infections involving DHPS mutants do not represent a public health issue in Brittany, western France.
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Affiliation(s)
- Solène Le Gal
- University of Brest, LUBEM EA 3882, SFR 148, Brest, France; Laboratory of Parasitology and Mycology, Brest University Hospital, Brest, France.
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Abstract
Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.
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Circulation of Pneumocystis dihydropteroate synthase mutants in France. Diagn Microbiol Infect Dis 2012; 74:119-24. [PMID: 22795965 DOI: 10.1016/j.diagmicrobio.2012.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/01/2012] [Accepted: 06/04/2012] [Indexed: 11/21/2022]
Abstract
Data on the prevalence of Pneumocystis jirovecii (P. jirovecii) dihydropteroate synthase (DHPS) mutants in France are still limited. In this study, mutant prevalence in the Brest region (western France) was determined. Archival pulmonary specimens from 85 patients infected with P. jirovecii and admitted to our institution (University Hospital, Brest) from October 2007 to February 2010 were retrospectively typed at the DHPS locus using a polymerase chain reaction-restriction fragment length polymorphism assay. Type identification was successful in 66 of 85 patients. Sixty-four patients were infected with a wild type, whereas mutants were found in 2 patients (2/66, 3%). Medical chart analysis revealed that these 2 patients usually lived in Paris. Another patient usually lived on the French Riviera, whereas 63 patients were from the city of Brest. Thus, the corrected prevalence of mutants in patients who effectively lived in our geographic area was 0% (0/63). Taking into account that i) Paris is characterized by a high prevalence of mutants from 18.5% to 40%, ii) infection diagnoses were performed in the 2 Parisians during their vacation <30 days, iii) infection incubation is assumed to last about 2 months, the results provide evidence of mutant circulation from Paris to Brest through infected vacationers. The study shows that the usual city of patient residence, rather than the city of infection diagnosis, is a predictor of mutants and that P. jirovecii infections involving mutants do not represent a public health issue in western France.
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Muñoz C, Zuluaga A, Restrepo A, Tobón A, Cano LE, Gonzalez A. Molecular diagnosis and detection of Pneumocystis jirovecii DHPS and DHFR genotypes in respiratory specimens from Colombian patients. Diagn Microbiol Infect Dis 2012; 72:204-13. [PMID: 22321995 DOI: 10.1016/j.diagmicrobio.2011.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/17/2011] [Accepted: 11/19/2011] [Indexed: 11/16/2022]
Abstract
A total of 98 respiratory specimens from 88 patients suspected of having Pneumocystis jirovecii pneumonia (PcP) were evaluated using a previously reported nested polymerase chain reaction (PCR) assay for mitochondrial large subunit rRNA (mtLSUrRNA). In addition, samples from patients with other pulmonary infections and a sizeable DNA collection from other fungal pathogens were studied. A panfungal PCR assay amplifying the ITS1-ITS2 regions were also used to identify all fungal DNAs. All samples positive for mtLSUrRNA-PCR were evaluated to determine mutations in dihydropteroate synthase (DHPS) and dihydrofolate reductase (DHFR) genes. All PCR-amplified products were sequenced. Of the 98 clinical specimens, 13 (13.2%) were positive by GMS stain and mtLSUrRNA-PCR, while 32 (32.6%) that were GMS stain-negative gave positive results with mtLSUrRNA-PCR. All the sequences corresponding to the 45 products amplified by mtLSUrRNA-PCR showed 99% or greater identity with P. jirovecii. The mtLSUrRNA-PCR exhibited 86% sensitivity and 98% and 96.6% specificity when results were compared to those corresponding to negative controls and other proven clinical entities, respectively. We found mutations in the DHPS gene in 3 (7.7%) patients, 2 located at codon 55 and 1 at codon 57. One patient showed a synonymous substitution at nucleotide position 312 in the DHFR gene. These results suggest that mtLSUrRNA-PCR is a useful test for diagnosing PcP. In contrast to other studies, this study found a low prevalence of mutations in the DHPS and DHFR genes in Colombian patients.
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Affiliation(s)
- Cesar Muñoz
- Medical and Experimental Mycology Group, Corporación para Investigaciones Biológicas, Medellín, Colombia
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Beser J, Dini L, Botero-Kleiven S, Krabbe M, Lindh J, Hagblom P. Absence of dihydropteroate synthase gene mutations inPneumocystis jiroveciiisolated from Swedish patients. Med Mycol 2012; 50:320-3. [DOI: 10.3109/13693786.2011.593051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Dihydropteroate synthase gene mutations in Pneumocystis jiroveci strains isolated from immunocompromised patients. ACTA ACUST UNITED AC 2011; 59:222-5. [DOI: 10.1016/j.patbio.2010.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 02/05/2010] [Indexed: 12/21/2022]
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Duan YN, Yi LH, Chen JL, Zhu DD, Wang JX, Feng JR, Qin YW, Zhu Y. Protective effect of DNA vaccine with the gene encoding 55kDa antigen fragment against Pneumocystis carinii in mice. ASIAN PAC J TROP MED 2011; 4:353-6. [PMID: 21771675 DOI: 10.1016/s1995-7645(11)60102-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 04/27/2011] [Accepted: 05/05/2011] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To evaluate the protective effect of DNA vaccine with the gene encoding 55kDa antigen fragment of Pneumocystis carinii (P. carinii) against P. carinii in mice. METHODS The fragment of the antigen within p55(p55-582) was cloned. Then recombinant plasmid was constructed based on the eukaryotic expression vector pcDNA3.1(+). BALB/c mice were used as experimental models to examine the immunogenicity of pcDNA3.1(+)-p55-582. ELISA and RT-PCR were used to evaluate the role of this kind of DNA vaccine. RESULTS The results of western blot indicated that the recombinant DNA[pcDNA3.1(+)-p55-582] could be expressed correctly and had antigenicity in transfected COS-7 cells. ELISA and RT-PCR showed that pcDNA3.1(+)-p55-582 elicited antibody production, stimulated lymphocyte proliferation and provided partial protection by reducing the P. carinii burden. CONCLUSIONS The data demonstrate that pcDNA3.1(+)-p55-582 might be potent vaccination that can afford the partial protection for the immunized animals.
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Affiliation(s)
- Yi-nong Duan
- Department of Parasitology and Microbiology, School of Medicine, Nantong University, Nantong, Jiangsu Province, 226001, China.
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Akgün KM, Pisani M, Crothers K. The changing epidemiology of HIV-infected patients in the intensive care unit. J Intensive Care Med 2011; 26:151-64. [PMID: 21436170 DOI: 10.1177/0885066610387996] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
With the introduction of highly active antiretroviral therapy (HAART), HIV has become a chronic disease. As HIV-infected patients are aging, they are at increased risk for comorbid diseases. These non-AIDS related diseases account for a growing proportion of intensive care unit (ICU) admissions in HIV-infected patients in recent studies. HIV-infected patients still present to the ICU with HIV-related conditions such as Pneumocystis jirovecii pneumonia (PCP), but these conditions are becoming less common. Respiratory failure remains the most common indication for ICU admission. Immune reconstitution inflammatory response syndrome and toxicities related to HAART may also result in ICU admission. While ICU survival has improved since the earliest era of the HIV epidemic, hospital mortality for HIV-infected patients admitted to the ICU remains around 30%. Risk factors for ICU mortality include poor functional status, weight loss, more than one year between HIV diagnosis and ICU admission, lower serum albumin, higher severity of illness, need for mechanical ventilation, and respiratory failure-particularly if due to PCP and accompanied by pneumothorax. The impact of HAART on ICU outcomes is unclear. HAART administration in the ICU can be challenging due to limited delivery routes, concern for viral resistance and medication toxicities. There are no data to determine the safety or efficacy of HAART initiation in the ICU. Future studies are needed to address the role of age, associated comorbidities and impact of HAART on outcomes of HIV-infected patients admitted to the ICU.
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Affiliation(s)
- Kathleen M Akgün
- Department of Internal Medicine, Pulmonary and Critical Care Section, Yale University School of Medicine, New Haven, CT, USA.
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Pneumocystis Jirovecii Pneumonia: Current Knowledge and Outstanding Public Health Issues. CURRENT FUNGAL INFECTION REPORTS 2010. [DOI: 10.1007/s12281-010-0029-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Alvarez-Martínez MJ, Miró JM, Valls ME, Mas J, de la Bellacasa JP, Sued O, Solé M, Rivas PV, de Lazzari E, Benito N, García F, Agustí C, Wilson PE, Gatell JM, Jiménez de Anta MT, Meshnick SR, Moreno A. Prevalence of dihydropteroate synthase genotypes before and after the introduction of combined antiretroviral therapy and their influence on the outcome of Pneumocystis pneumonia in HIV-1-infected patients. Diagn Microbiol Infect Dis 2010; 68:60-5. [PMID: 20727472 DOI: 10.1016/j.diagmicrobio.2010.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 04/08/2010] [Accepted: 04/09/2010] [Indexed: 02/08/2023]
Abstract
The objective of this study was to determine whether the prevalence of Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations has changed since the introduction of combined antiretroviral therapy (cART) and whether the mutations are associated with poor outcome in Spanish HIV-1-infected patients with Pneumocystis pneumonia (PcP). We studied 167 PcP episodes in HIV-1-infected patients diagnosed during the pre-cART (1989-1995) and cART (2001-2004) periods. Molecular genotyping of DHPS was successfully performed in 98 patients (43 pre-cART and 55 cART). Seventeen patients (17/98, 17%; 95% confidence interval [CI], 10-25%) had mutations in the DHPS gene: 14 patients (14/43, 33%; 95% CI, 19-49%) from the pre-cART period and 3 patients (3/55, 5.5%; 95% CI, 1.3-16%) from the cART period (P < 0.01). In the multivariate analysis, the pre-cART period, previous PcP prophylaxis with sulfa drugs, and homosexuality as an HIV risk factor were found to be associated with a higher risk of presenting DHPS mutations. Overall, 95% of patients were treated with trimethoprim and sulfamethoxazole (TMP-SMX). In-hospital mortality was similar in patients with (out) mutations (6% versus 11%, P = 0.84). DHPS gene mutations were more common during the pre-cART period and were associated with previous sulfa exposure and homosexuality. However, their presence did not worsen prognosis of PcP. The response to TMP-SMX with therapeutic doses was successful in most cases.
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Affiliation(s)
- Míriam J Alvarez-Martínez
- Hospital Clínic-IDIBAPS (Institut d'Investigació August Pi i Sunyer), Universitat de Barcelona, Barcelona, Spain
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Matos O, Esteves F. Pneumocystis jirovecii multilocus gene sequencing: findings and implications. Future Microbiol 2010; 5:1257-67. [DOI: 10.2217/fmb.10.75] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pneumocystis jirovecii pneumonia (PcP) remains a major cause of respiratory illness among immunocompromised patients, especially patients infected with HIV, but it has also been isolated from immunocompetent persons. This article discusses the application of multilocus genotyping analysis to the study of the genetic diversity of P. jirovecii and its epidemiological and clinical parameters, and the important concepts achieved to date with these approaches. The multilocus typing studies performed until now have shown that there is an important genetic diversity of stable and ubiquitous P. jirovecii genotypes; infection with P. jirovecii is not necessarily clonal, recombination between some P. jirovecii multilocus genotypes has been suggested. P. jirovecii-specific multilocus genotypes can be associated with severity of PcP. Patients infected with P. jirovecii, regardless of the form of infection they present with, are part of a common human reservoir for future infections. The CYB, DHFR, DHPS, mtLSU rRNA, SOD and the ITS loci are suitable genetic targets to be used in further epidemiological studies focused on the identification and characterization of P. jirovecii haplotypes correlated with drug resistance and PcP outcome.
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Affiliation(s)
| | - Francisco Esteves
- Unidade de Protozoários Oportunistas/VIH e Outras Protozooses, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal
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Catherinot E, Lanternier F, Bougnoux ME, Lecuit M, Couderc LJ, Lortholary O. Pneumocystis jirovecii Pneumonia. Infect Dis Clin North Am 2010; 24:107-38. [PMID: 20171548 DOI: 10.1016/j.idc.2009.10.010] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pneumocystis jirovecii has gained attention during the last decade in the context of the AIDS epidemic and the increasing use of cytotoxic and immunosuppressive therapies. This article summarizes current knowledge on biology, pathophysiology, epidemiology, diagnosis, prevention, and treatment of pulmonary P jirovecii infection, with a particular focus on the evolving pathophysiology and epidemiology. Pneumocystis pneumonia still remains a severe opportunistic infection, associated with a high mortality rate.
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Affiliation(s)
- Emilie Catherinot
- Université Paris Descartes, Service de Maladies Infectieuses et Tropicales, 149 Rue de Sèvres, Centre d'Infectiologie Necker-Pasteur, Hôpital Necker-Enfants Malades, Paris 75015, France
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37
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Moukhlis R, Boyer J, Lacube P, Bolognini J, Roux P, Hennequin C. Linking Pneumocystis jiroveci sulfamethoxazole resistance to the alleles of the DHPS gene using functional complementation in Saccharomyces cerevisiae. Clin Microbiol Infect 2009; 16:501-7. [PMID: 19673964 DOI: 10.1111/j.1469-0691.2009.02833.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Curative and prophylactic therapy for Pneumocystis jiroveci pneumonia relies mainly on cotrimoxazole, an association of trimethoprim and sulfamethoxazole (SMX). SMX inhibits the folic acid pathway through competition with para-aminobenzoic acid (pABA), one of the two substrates of the dihydropteroate synthase (DHPS), a key enzyme in de novo folic acid synthesis. The most frequent non-synonymous single nucleotide polymorphisms (SNPs) in P. jiroveci DHPS are seen at positions 165 and 171, the combination leading to four possible different genetic alleles. A number of reports correlate prophylaxis failure and mutation in the P. jiroveci DHPS but, because of the impossibility of reliably cultivating P. jiroveci, the link between DHPS mutation(s) and SMX susceptibility is not definitively proven. To circumvent this limitation, the yeast Saccharomyces cerevisiae was used as a model. The introduction of the P. jiroveci DHPS gene, with or without point mutations, directly amplified from a clinical specimen and cloned in a centromeric plasmid into a DHPS-deleted yeast strain, allowed a fully effective complementation. However, in the presence of SMX at concentrations >250 mg/L, yeasts complemented with the double mutated allele showed a lower susceptibility compared with strains complemented with either a single mutated allele or wild-type alleles. These results confirm the need for prospective study of pneumocystosis, including systematic determination of the DHPS genotype, to clarify further the impact of mutations on clinical outcome. Additionally, the S. cerevisiae model proves to be useful for the study of still uninvestigated biological properties of P. jiroveci.
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Affiliation(s)
- R Moukhlis
- Université Pierre et Marie Curie, Paris, France
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38
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Costa MC, Gaspar J, Mansinho K, Esteves F, Antunes F, Matos O. Detection of Pneumocystis jirovecii dihydropteroate synthase polymorphisms in patients with Pneumocystis pneumonia. ACTA ACUST UNITED AC 2009; 37:766-71. [PMID: 16191898 DOI: 10.1080/00365540510038505] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In the present study, in order to improve the detection of Pneumocystis jirovecii dihydropteroate synthase (DHPS) mutations in pulmonary specimens of HIV-infected patients with P. jirovecii pneumonia, we evaluated a microfiltration procedure for the removal of human cell contamination and a nested-PCR method, for amplification in specimens with low parasite load. In the studied population, PCR amplification of the DHPS gene was more successful in unfiltered than in filtered specimens, with both touchdown-PCR and nested-PCR procedures (p<0.05 and p<0.001, respectively), but the amount of host DNA in the samples analysed seems to be inversely related with the successful PCR parasite detection. Amplification of P. jirovecii DHPS gene with nested-PCR was achieved in 77.5% of the specimens studied, demonstrating that this is a useful method for the identification of mutations in pulmonary specimens, including samples with low parasite loads, and will facilitate the evaluation of the relationship between the P. jirovecii DHPS polymorphisms and clinical resistance to sulfa drugs.
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Affiliation(s)
- M C Costa
- Unidade de Protozoários Oportunistas/VIH e outras Protozooses, Unidade de Parasitologia e Microbiologia Médicas (UPMM), Instituto de Higiene e Medicina Tropical, Lisboa, Portugal
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Prevalence of dihydropteroate synthase mutations in Spanish patients with HIV-associated Pneumocystis pneumonia. Diagn Microbiol Infect Dis 2009; 64:104-5; author reply 106-7. [DOI: 10.1016/j.diagmicrobio.2009.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 01/21/2009] [Indexed: 11/19/2022]
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40
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Response to Dr. Friaza submission: “Prevalence of dihydropteroate synthase mutations in Spanish patients with HIV-associated Pneumocystis pneumonia”. Diagn Microbiol Infect Dis 2009. [DOI: 10.1016/j.diagmicrobio.2009.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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41
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Ramesh M, Chandrasekar PH. Effective alternates to trimethoprim-sulfamethoxazole as antimicrobial prophylaxis in stem cell recipients: are there any? Pediatr Transplant 2008; 12:823-6. [PMID: 18518908 DOI: 10.1111/j.1399-3046.2008.00987.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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Alvarez-Martínez MJ, Moreno A, Miró JM, Valls ME, Rivas PV, de Lazzari E, Sued O, Benito N, Domingo P, Ribera E, Santín M, Sirera G, Segura F, Vidal F, Rodríguez F, Riera M, Cordero ME, Arribas JR, Jiménez de Anta MT, Gatell JM, Wilson PE, Meshnick SR. Pneumocystis jirovecii pneumonia in Spanish HIV-infected patients in the combined antiretroviral therapy era: prevalence of dihydropteroate synthase mutations and prognostic factors of mortality. Diagn Microbiol Infect Dis 2008; 62:34-43. [PMID: 18554841 DOI: 10.1016/j.diagmicrobio.2008.04.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 03/14/2008] [Accepted: 04/16/2008] [Indexed: 02/08/2023]
Abstract
The incidence of Pneumocystis jirovecii pneumonia (PCP) in HIV-infected patients has decreased thanks to sulfa prophylaxis and combined antiretroviral therapy. The influence of P. jirovecii dihydropteroate synthase (DHPS) gene mutations on survival is controversial and has not been reported in Spain. This prospective multicenter study enrolled 207 HIV-infected patients with PCP from 2000 to 2004. Molecular genotyping was performed on stored specimens. Risk factors for intensive care unit (ICU) admission and mortality were identified using a logistic regression model. Seven patients (3.7%; 95% confidence interval [CI], 1.5-7.5%) had DHPS mutations. Overall mortality was 15% (95% CI, 10-21%), rising to 80% (95% CI, 61-92%) in patients requiring mechanical ventilation. None of the patients with DHPS mutants died, nor did they need ICU admission or mechanical ventilation. PaO(2) <60 mm Hg at admission was a predictor of ICU admission (P = 0.01), and previous antiretroviral therapy predicted non-ICU admission (P = 0.009). PaO(2) <60 mm Hg at admission and ICU admission during the 1st week were predictors of mortality (P = 0.03 and P < 0.001, respectively). The prevalence of DHPS mutants in Spain is low and is not associated with a worse outcome. Severe respiratory failure at admission is the strongest predictor of PCP outcome.
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Esteves F, Montes-Cano M, Horra CDL, Costa M, Calderón E, Antunes F, Matos O. Pneumocystis jirovecii multilocus genotyping profiles in patients from Portugal and Spain. Clin Microbiol Infect 2008; 14:356-62. [DOI: 10.1111/j.1469-0691.2007.01944.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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45
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Huang L, Welsh DA, Miller RF, Beard CB, Lawrence GG, Fox M, Swartzman A, Bensley MR, Carbonnet D, Davis JL, Chi A, Yoo BJ, Jones JL. Pneumocystis jirovecii dihydropteroate synthase gene mutations and human immunodeficiency virus-associated Pneumocystis pneumonia. J Eukaryot Microbiol 2007; 53 Suppl 1:S114-6. [PMID: 17169022 DOI: 10.1111/j.1550-7408.2006.00195.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Laurence Huang
- HIV/AIDS Division, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California 94110, USA.
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Rabodonirina M, Nahimana A, Weber R, Francioli P, Bille J, Hauser PM. Geographical variation in the prevalence of Pneumocystis jirovecii dihydropteroate synthase mutations within Western Europe. J Eukaryot Microbiol 2007; 53 Suppl 1:S112-3. [PMID: 17169021 DOI: 10.1111/j.1550-7408.2006.00194.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Meja Rabodonirina
- Parasitology Unit, Croix-Rousse Hospital, Hospices Civils de Lyon, 103 Grande-Rue de la Croix-Rousse, 69317 Lyon Cedex 04, France.
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Valerio A, Tronconi E, Mazza F, Fantoni G, Atzori C, Tartarone F, Duca P, Cargnel A. Genotyping of Pneumocystis jiroveci pneumonia in Italian AIDS patients. Clinical outcome is influenced by dihydropteroate synthase and not by internal transcribed spacer genotype. J Acquir Immune Defic Syndr 2007; 45:521-8. [PMID: 17558331 DOI: 10.1097/qai.0b013e3180decbe2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Two Pneumocystis jiroveci independent genomic regions, internal transcribed spacer (ITS) 1 and ITS2, and dihydropteroate synthase (DHPS) gene have been used for typing a cohort of HIV-infected Italian patients with P jiroveci pneumonia (PcP). METHODS Bronchoalveolar lavage samples isolated from 207 HIV-infected adults were ITS and DHPS genotyped by DNA sequencing and by restriction fragment length polymorphism analysis, respectively. Mutant DHPS samples were cloned and ITS typed. Data on severity, treatment, and outcome of PcP were obtained by chart review. RESULTS High diversity with 46 different ITS genotypes was observed. At the DHPS locus, 9.1% of samples analyzed were found to be mutated. A correlation was observed between DHPS mutants and greater severity of PcP, as defined by higher lactate dehydrogenase (P = 0.015) and need for intubation (P = 0.002), and worse outcomes, as defined by failure of sulfa treatment (P = 0.04), death, and/or relapse of PcP (P = 0.008). There was a significant difference in ITS genotype patterns between DHPS wild-type and mutants (P = 0.028). CONCLUSIONS The present data suggest the absence of a correlation between P jiroveci ITS types and specific clinical characteristics. DHPS mutations correlate with possible failure of anti-P jiroveci sulfa therapy, and a trend of association is shown between DHPS mutations and some clinical PcP features.
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Affiliation(s)
- Antonella Valerio
- II Department of Infectious Diseases, Luigi Sacco Hospital, Milan, Italy
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Walker DJ, Meshnick SR. Drug resistance in Pneumocystis carinii: an emerging problem. Drug Resist Updat 2007; 1:201-4. [PMID: 17092806 DOI: 10.1016/s1368-7646(98)80040-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/1998] [Revised: 04/15/1998] [Accepted: 04/17/1998] [Indexed: 10/25/2022]
Abstract
Pneumocystis carinii pneumonia (PCP) is a frequent opportunistic infection in AIDS patients. Large numbers of HIV-infected individuals take prophylactic medications to prevent this illness. The development of drug resistance, while expected, cannot be monitored by classical means, since the organism cannot be cultivated in vitro. Two drug target genes, dihydropteroate synthase (DHPS) and cytochrome b, have been cloned and sequenced from human-derived P. carinii. Mutations leading to amino acid substitutions in the active sites of both proteins have been detected in patients receiving prophylaxis with sulfonamides and sulfones (DHPS inhibitors) and with atovaquone (cytochrome b inhibitor), suggesting that drug resistance may indeed be developing.
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Affiliation(s)
- D J Walker
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
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Scemama J, Amathieu R, Tual L, Fessenmeyer C, Stirnemann J, Dhonneur G. Échec de traitement d'une pneumocystose par le cotrimoxazole: rôle de la co-infection par le cytomégalovirus? ACTA ACUST UNITED AC 2007; 26:604-7. [PMID: 17433609 DOI: 10.1016/j.annfar.2007.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 02/21/2007] [Indexed: 11/19/2022]
Abstract
Pneumocystis jiroveci pneumonia is a classic opportunist infection affecting AIDS patients. However it is less frequent since systematic prophylaxis and antiretroviral therapies. Treatment resistance is rare in France. We report the case of a severe Pneumocystis jiroveci pneumonia with treatment resistance to standard treatment and fatal outcome. The different causes of treatment resistance, notably the role of CMV co-infection, were reviewed and discussed.
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Affiliation(s)
- J Scemama
- Service d'anesthésie et de réanimation, CHU Jean-Verdier, APHP, Bondy, France
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50
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de Oliveira A, Unnasch TR, Crothers K, Eiser S, Zucchi P, Moir J, Beard CB, Lawrence GG, Huang L. Performance of a molecular viability assay for the diagnosis of Pneumocystis pneumonia in HIV-infected patients. Diagn Microbiol Infect Dis 2006; 57:169-76. [PMID: 17049800 DOI: 10.1016/j.diagmicrobio.2006.08.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 08/14/2006] [Accepted: 08/17/2006] [Indexed: 11/26/2022]
Abstract
Pneumocystis pneumonia (PCP), caused by infection with Pneumocystis jirovecii, remains an important opportunistic infection in humans. A reverse transcriptase polymerase chain reaction assay has been shown to specifically detect viable P. jirovecii organisms. In the current study, we evaluated this assay on different types of respiratory samples. The assay had a diagnostic sensitivity of 100% and a specificity of 86% when applied to bronchoalveolar lavage samples. The assay's performance declined when applied to less invasive induced sputum and oropharyngeal wash (OPW) samples. The sensitivity, when applied to OPWs, was improved by examining multiple sequential OPW samples and was affected by clinical sampling parameters that could increase or decrease the number of potential organisms in the oropharynx. When used in conjunction with an optimized clinical sampling protocol, this assay may become a useful tool for detecting and monitoring P. jirovecii in minimally invasive clinical samples.
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Affiliation(s)
- Ana de Oliveira
- Division of Geographic Medicine, BBRB Box 7, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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