1
|
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.
Collapse
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
| |
Collapse
|
2
|
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.
Collapse
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.)
| |
Collapse
|
3
|
Huang YS, Yang JJ, Lee NY, Chen GJ, Ko WC, Sun HY, Hung CC. Treatment of Pneumocystis jirovecii pneumonia in HIV-infected patients: a review. Expert Rev Anti Infect Ther 2017; 15:873-892. [PMID: 28782390 DOI: 10.1080/14787210.2017.1364991] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Pneumocystis pneumonia is a potentially life-threatening pulmonary infection that occurs in immunocompromised individuals and HIV-infected patients with a low CD4 cell count. Trimethoprim-sulfamethoxazole has been used as the first-line agent for treatment, but mutations within dihydropteroate synthase gene render potential resistance to sulfamide. Despite advances of combination antiretroviral therapy (cART), Pneumocystis pneumonia continues to occur in HIV-infected patients with late presentation for cART or virological and immunological failure after receiving cART. Areas covered: This review summarizes the diagnosis and first-line and alternative treatment and prophylaxis for Pneumocystis pneumonia in HIV-infected patients. Articles for this review were identified through searching PubMed. Search terms included: 'Pneumocystis pneumonia', 'Pneumocystis jirovecii pneumonia', 'Pneumocystis carinii pneumonia', 'trimethoprim-sulfamethoxazole', 'primaquine', 'trimetrexate', 'dapsone', 'pentamidine', 'atovaquone', 'echinocandins', 'human immunodeficiency virus infection', 'acquired immunodeficiency syndrome', 'resistance to sulfamide' and combinations of these terms. We limited the search to English language papers that were published between 1981 and March 2017. We screened all identified articles and cross-referenced studies from retrieved articles. Expert commentary: Trimethoprim-sulfamethoxazole will continue to be the first-line agent for Pneumocystis pneumonia given its cost, availability of both oral and parenteral formulations, and effectiveness or efficacy in both treatment and prophylaxis. Whether resistance due to mutations within dihydropteroate synthase gene compromises treatment effectiveness remains controversial. Continued search for effective alternatives with better safety profiles for Pneumocystis pneumonia is warranted.
Collapse
Affiliation(s)
- Yu-Shan Huang
- a Department of Internal Medicine , National Taiwan University Hospital Hsin-Chu Branch , Hsin-Chu , Taiwan
| | - Jen-Jia Yang
- b Department of Internal Medicine , Po Jen General Hospital , Taipei , Taiwan
| | - Nan-Yao Lee
- c Department of Internal Medicine , National Cheng Kung University Hospital , Tainan , Taiwan.,d Department of Medicine , College of Medicine, National Cheng Kung University , Tainan , Taiwan
| | - Guan-Jhou Chen
- e Department of Internal Medicine , National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei , Taiwan
| | - Wen-Chien Ko
- c Department of Internal Medicine , National Cheng Kung University Hospital , Tainan , Taiwan.,d Department of Medicine , College of Medicine, National Cheng Kung University , Tainan , Taiwan
| | - Hsin-Yun Sun
- e Department of Internal Medicine , National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei , Taiwan
| | - Chien-Ching Hung
- e Department of Internal Medicine , National Taiwan University Hospital and National Taiwan University College of Medicine , Taipei , Taiwan.,f Department of Parasitology , National Taiwan University College of Medicine , Taipei , Taiwan.,g Department of Medical Research , China Medical University Hospital , Taichung , Taiwan.,h China Medical University , Taichung , Taiwan
| |
Collapse
|
4
|
Abstract
Pneumocystis pneumonia (PCP) is an opportunistic infection that occurs in humans and other mammals with debilitated immune systems. These infections are caused by fungi in the genus Pneumocystis, which are not susceptible to standard antifungal agents. Despite decades of research and drug development, the primary treatment and prophylaxis for PCP remains a combination of trimethoprim (TMP) and sulfamethoxazole (SMX) that targets two enzymes in folic acid biosynthesis, dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS), respectively. There is growing evidence of emerging resistance by Pneumocystis jirovecii (the species that infects humans) to TMP-SMX associated with mutations in the targeted enzymes. In the present study, we report the development of an accurate quantitative model to predict changes in the binding affinity of inhibitors (Ki, IC50) to the mutated proteins. The model is based on evolutionary information and amino acid covariance analysis. Predicted changes in binding affinity upon mutations highly correlate with the experimentally measured data. While trained on Pneumocystis jirovecii DHFR/TMP data, the model shows similar or better performance when evaluated on the resistance data for a different inhibitor of PjDFHR, another drug/target pair (PjDHPS/SMX) and another organism (Staphylococcus aureus DHFR/TMP). Therefore, we anticipate that the developed prediction model will be useful in the evaluation of possible resistance of the newly sequenced variants of the pathogen and can be extended to other drug targets and organisms.
Collapse
|
5
|
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
|
6
|
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]
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Vanspauwen MJ, Knops VEJ, Bruggeman CA, van Mook WNKA, Linssen CFM. Molecular epidemiology of Pneumocystis jiroveci in human immunodeficiency virus-positive and -negative immunocompromised patients in The Netherlands. J Med Microbiol 2014; 63:1294-1302. [PMID: 25060971 DOI: 10.1099/jmm.0.076257-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pneumocystis jiroveci infections can cause pneumocystis pneumonia (PCP) or lead to colonization without signs of PCP. Over the years, different genotypes of P. jiroveci have been discovered. Genomic typing of P. jiroveci in different subpopulations can contribute to unravelling the pathogenesis, transmission and spread of the different genotypes. In this study, we wanted to determine the distribution of P. jiroveci genotypes in immunocompetent and immunocompromised patients in The Netherlands and determine the clinical relevance of these detected mutations. A real-time PCR targeting the major surface glycoprotein gene (MSG) was used as a screening test for the presence of P. jiroveci DNA. Samples positive for MSG were genotyped based on the internal transcribed spacer (ITS) and dihydropteroate synthase (DHPS) genes. Of the 595 included bronchoalveolar lavage fluid samples, 116 revealed the presence of P. jiroveci DNA. A total of 52 of the 116 samples were ITS genotyped and 58 DHPS genotyped. The ITS genotyping revealed 17 ITS types, including two types that have not been described previously. There was no correlation between ITS genotype and underlying disease. All ITS- and DHPS-genotyped samples were found in immunocompromised patients. Of the 58 DHPS-genotyped samples, 50 were found to be WT. The other eight samples revealed a mixed genotype consisting of WT and type 1. The majority of the latter recovered on trimethoprim-sulfamethoxazole suggesting no clinical relevance for this mutation.
Collapse
Affiliation(s)
- Marijke J Vanspauwen
- Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Vera E J Knops
- Department of Medical Microbiology, Atrium Medical Centre, Heerlen, The Netherlands.,Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Cathrien A Bruggeman
- Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Walther N K A van Mook
- Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Intensive Care Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Catharina F M Linssen
- Department of Medical Microbiology, Atrium Medical Centre, Heerlen, The Netherlands.,Department of Medical Microbiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Dimonte S, Berrilli F, D’Orazi C, D’Alfonso R, Placco F, Bordi E, Perno C, Di Cave D. Molecular analysis based on mtLSU-rRNA and DHPS sequences of Pneumocystis jirovecii from immunocompromised and immunocompetent patients in Italy. INFECTION GENETICS AND EVOLUTION 2013. [DOI: 10.1016/j.meegid.2012.11.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
11
|
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.
Collapse
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.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
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.
Collapse
|
13
|
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.
Collapse
Affiliation(s)
- Cesar Muñoz
- Medical and Experimental Mycology Group, Corporación para Investigaciones Biológicas, Medellín, Colombia
| | | | | | | | | | | |
Collapse
|
14
|
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]
|
15
|
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.
Collapse
|
16
|
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.
| | | | | | | | | | | |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
- Antonella Valerio
- II Department of Infectious Diseases, Luigi Sacco Hospital, Milan, Italy
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Robien K, Boynton A, Ulrich CM. Pharmacogenetics of folate-related drug targets in cancer treatment. Pharmacogenomics 2006; 6:673-89. [PMID: 16207145 DOI: 10.2217/14622416.6.7.673] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Folate metabolism is the target of two major drug groups: folate antagonists (for example, methotrexate) and thymidylate synthase inhibitors (for example, 5-fluorouracil). These agents are used in the treatment of cancer, as well as for other conditions, such as rheumatoid arthritis. High-dose cancer treatment protocols can induce a state of acute folate depletion which may lead to significant treatment-related toxicity. Polymorphisms in folate-metabolizing enzymes may modify the therapeutic effectiveness and toxicity of these drugs. This review briefly summarizes the drugs targeting the folate pathway and describes common polymorphisms in folate-metabolizing enzymes and transport proteins. Pharmacogenetic studies investigating folate-related drug targets in the treatment of colorectal cancers and hematologic malignancies will subsequently be discussed. Findings to date illustrate a potential for targeting therapy based on patients' genotypes, in order to improve outcomes and reduce toxicity. However, larger, well-designed studies are needed to confirm these early findings.
Collapse
Affiliation(s)
- Kim Robien
- Fred Hutchinson Cancer Research Center, Cancer Prevention Program, 1100 Fairview Ave N, M4-B402, Seattle, WA 98109 1024, USA
| | | | | |
Collapse
|
19
|
Robberts FJL, Chalkley LJ, Weyer K, Goussard P, Liebowitz LD. Dihydropteroate synthase and novel dihydrofolate reductase gene mutations in strains of Pneumocystis jirovecii from South Africa. J Clin Microbiol 2005; 43:1443-4. [PMID: 15750128 PMCID: PMC1081295 DOI: 10.1128/jcm.43.3.1443-1444.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dihydropteroate synthase (DHPS) gene mutations have raised concerns about emerging sulfonamide resistance in Pneumocystis jirovecii. DHPS and dihydrofolate reductase (DHFR) gene products were amplified in clinical specimens from South African patients. One of 53 DHPS genes sequenced contained the double mutation Thr55Ala Pro57Ser. DHFR gene mutations detected were Ala67Val and the new mutations Arg59Gly and C278T.
Collapse
Affiliation(s)
- F J L Robberts
- Department of Medical Microbiology, University of Stellenbosch, Tygerberg 7500, South Africa.
| | | | | | | | | |
Collapse
|
20
|
Iliades P, Meshnick SR, Macreadie IG. Mutations in the Pneumocystis jirovecii DHPS gene confer cross-resistance to sulfa drugs. Antimicrob Agents Chemother 2005; 49:741-8. [PMID: 15673759 PMCID: PMC547354 DOI: 10.1128/aac.49.2.741-748.2005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pneumocystis jirovecii is a major opportunistic pathogen that causes Pneumocystis pneumonia (PCP) and results in a high degree of mortality in immunocompromised individuals. The drug of choice for PCP is typically sulfamethoxazole (SMX) or dapsone in conjunction with trimethoprim. Drug treatment failure and sulfa drug resistance have been implicated epidemiologically with point mutations in dihydropteroate synthase (DHPS) of P. jirovecii. P. jirovecii cannot be cultured in vitro; however, heterologous complementation of the P. jirovecii trifunctional folic acid synthesis (PjFAS) genes with an E. coli DHPS-disrupted strain was recently achieved. This enabled the evaluation of SMX resistance conferred by DHPS mutations. In this study, we sought to determine whether DHPS mutations conferred sulfa drug cross-resistance to 15 commonly available sulfa drugs. It was established that the presence of amino acid substitutions (T(517)A or P(519)S) in the DHPS domain of PjFAS led to cross-resistance against most sulfa drugs evaluated. The presence of both mutations led to increased sulfa drug resistance, suggesting cooperativity and the incremental evolution of sulfa drug resistance. Two sulfa drugs (sulfachloropyridazine [SCP] and sulfamethoxypyridazine [SMP]) that had a higher inhibitory potential than SMX were identified. In addition, SCP, SMP, and sulfadiazine (SDZ) were found to be capable of inhibiting the clinically observed drug-resistant mutants. We propose that SCP, SMP, and SDZ should be considered for clinical evaluation against PCP or for future development of novel sulfa drug compounds.
Collapse
Affiliation(s)
- Peter Iliades
- CSIRO Health Sciences and Nutrition, 343 Royal Parade, Parkville, Victoria 3052, Australia.
| | | | | |
Collapse
|
21
|
Iliades P, Meshnick SR, Macreadie IG. Analysis ofPneumocystis jiroveciiDHPS Alleles Implicated in Sulfamethoxazole Resistance Using anEscherichia coliModel System. Microb Drug Resist 2005; 11:1-8. [PMID: 15770087 DOI: 10.1089/mdr.2005.11.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pneumocystis jirovecii is a major opportunistic pathogen that causes Pneumocystis pneumonia (PCP). Drug treatment failure has been associated epidemiologically with point mutations in the gene for dihydropteroate synthase which is part of a gene that encodes three covalently linked enzymes involved in folic acid synthesis (FAS). The evaluation of whether mutations found in P. jirovecii FAS lead to sulfa drug resistance is hampered by the lack of a culture system for P. jirovecii as well as the failure of P. jirovecii FAS to complement in a heterologous system. Therefore, we chose to model the P. jirovecii mutations in the Saccharomyces cerevisiae FAS protein (encoded by FOL1) via its expression in Escherichia coli. An optimized drug diffusion assay was used to evaluate the FAS mutants against 15 sulfa drugs. It was established that the single amino acid substitution, P599S, in the (DHPS) domain of FAS led to sulfa drug resistance, whereas the T597A substitution led to increased sensitivity. The presence of both mutations (T597A and P599S) was cooperative and led to increased sulfa drug resistance. Analysis of a novel double mutant, (T597V P599S) was found to have significantly higher sulfa drug resistance than the T597A P599S mutant. These data suggest that further amino acid substitutions may lead to the evolution of higher sulfa drug resistance. Two sulfa drugs (sulfachloropyridazine and sulfathiazole) were identified that had higher inhibitory potential than sulfamethoxazole, which is currently the preferred treatment for PCP.
Collapse
Affiliation(s)
- Peter Iliades
- CSIRO Health Sciences and Nutrition, Parkville, Victoria, 3052, Australia.
| | | | | |
Collapse
|
22
|
Huang L, Crothers K, Atzori C, Benfield T, Miller R, Rabodonirina M, Helweg-Larsen J. Dihydropteroate synthase gene mutations in Pneumocystis and sulfa resistance. Emerg Infect Dis 2004; 10:1721-8. [PMID: 15504256 PMCID: PMC3323267 DOI: 10.3201/eid1010.030994] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
We review studies of dihydropteroate synthase gene mutations in Pneumocystis jirovecii and summarize the evidence for resistance to sulfamethoxazole and dapsone. Pneumocystis pneumonia (PCP) remains a major cause of illness and death in HIV-infected persons. Sulfa drugs, trimethoprim-sulfamethoxazole (TMP-SMX) and dapsone are mainstays of PCP treatment and prophylaxis. While prophylaxis has reduced the incidence of PCP, its use has raised concerns about development of resistant organisms. The inability to culture human Pneumocystis, Pneumocystis jirovecii, in a standardized culture system prevents routine susceptibility testing and detection of drug resistance. In other microorganisms, sulfa drug resistance has resulted from specific point mutations in the dihydropteroate synthase (DHPS) gene. Similar mutations have been observed in P. jirovecii. Studies have consistently demonstrated a significant association between the use of sulfa drugs for PCP prophylaxis and DHPS gene mutations. Whether these mutations confer resistance to TMP-SMX or dapsone plus trimethoprim for PCP treatment remains unclear. We review studies of DHPS mutations in P. jirovecii and summarize the evidence for resistance to sulfamethoxazole and dapsone.
Collapse
|
23
|
Stein CR, Poole C, Kazanjian P, Meshnick SR. Sulfa use, dihydropteroate synthase mutations, and Pneumocystis jirovecii pneumonia. Emerg Infect Dis 2004; 10:1760-5. [PMID: 15504261 PMCID: PMC3323254 DOI: 10.3201/eid1010.040362] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Meta-analysis shows increased risk for DHPS mutations in patients exposed to sulfa prophylaxis for PCP, but clinical relevance of mutations is not known. A systematic review was conducted to examine the associations in Pneumocystis jirovecii pneumonia (PCP) patients between dihydropteroate synthase (DHPS) mutations and sulfa or sulfone (sulfa) prophylaxis and between DHPS mutations and sulfa treatment outcome. Selection criteria included study populations composed entirely of PCP patients and mutation or treatment outcome results for all patients, regardless of exposure status. Based on 13 studies, the risk of developing DHPS mutations is higher for PCP patients receiving sulfa prophylaxis than for PCP patients not receiving sulfa prophylaxis (p < 0.001). Results are too heterogeneous (p < 0.001) to warrant a single summary effect estimate. Estimated effects are weaker after 1996 and stronger in studies that included multiple isolates per patient. Five studies examined treatment outcome. The effect of DHPS mutations on treatment outcome has not been well studied, and the few studies that have been conducted are inconsistent even as to the presence or absence of an association.
Collapse
Affiliation(s)
- Cheryl R Stein
- Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, North Carolina 27599-7435, USA.
| | | | | | | |
Collapse
|
24
|
Iliades P, Meshnick SR, Macreadie IG. Dihydropteroate synthase mutations in Pneumocystis jiroveci can affect sulfamethoxazole resistance in a Saccharomyces cerevisiae model. Antimicrob Agents Chemother 2004; 48:2617-23. [PMID: 15215118 PMCID: PMC434176 DOI: 10.1128/aac.48.7.2617-2623.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dihydropteroate synthase (DHPS) mutations in Pneumocystis jiroveci have been associated epidemiologically with resistance to sulfamethoxazole (SMX). Since P. jiroveci cannot be cultured, inherent drug resistance cannot be measured. This study explores the effects of these mutations in a tractable model organism, Saccharomyces cerevisiae. Based on the sequence conservation between the DHPS enzymes of P. jiroveci and S. cerevisiae, together with the structural conservation of the three known DHPS structures, DHPS substitutions commonly observed in P. jiroveci were reverse engineered into the S. cerevisiae DHPS. Those mutations, T(597)A and P(599)S, can occur singly but are most commonly found together and are associated with SMX treatment failure. Mutations encoding the corresponding changes in the S. cerevisiae dhps were made in a yeast centromere vector, p414FYC, which encodes the native yeast DHPS as part of a trifunctional protein that also includes the two enzymes upstream of DHPS in the folic acid synthesis pathway, dihydroneopterin aldolase and 2-amino-4-hydroxymethyl dihydropteridine pyrophosphokinase. A yeast strain with dhps deleted was employed as the host strain, and transformants having DHPS activity were recovered. Mutants having both T(597) and P(599) substitutions had a requirement for p-aminobenzoic acid (PABA), consistent with resistance being associated with altered substrate binding. These mutants could be adapted for growth in the absence of PABA, which coincided with increased sulfa drug resistance. Upregulated PABA synthesis was thus implicated as a mechanism for sulfa drug resistance for mutants having two DHPS substitutions.
Collapse
Affiliation(s)
- Peter Iliades
- CSIRO Health Sciences and Nutrition, 343 Royal Parade, Parkville, Victoria 3052, Australia.
| | | | | |
Collapse
|
25
|
|
26
|
Totet A, Latouche S, Lacube P, Pautard JC, Jounieaux V, Raccurt C, Roux P, Nevez G. Pneumocystis jirovecii dihydropteroate synthase genotypes in immunocompetent infants and immunosuppressed adults, Amiens, France. Emerg Infect Dis 2004; 10:667-73. [PMID: 15200857 PMCID: PMC3323070 DOI: 10.3201/eid1004.030451] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To date, investigations of Pneumocystis jiroveci circulation in the human reservoir through the dihydropteroate synthase (DHPS) locus analysis have only been conducted by examining P. jirovecii isolates from immunosuppressed patients with Pneumocystis pneumonia (PCP). Our study identifies P. jirovecii genotypes at this locus in 33 immunocompetent infants colonized with P. jirovecii contemporaneously with a bronchiolitis episode and in 13 adults with PCP; both groups of patients were monitored in Amiens, France. The results have pointed out identical features of P. jirovecii DHPS genotypes in the two groups, suggesting that in these two groups, transmission cycles of P. jirovecii infections are linked. If these two groups represent sentinel populations for P. jirovecii infections, our results suggest that all persons parasitized by P. jirovecii, whatever their risk factor for infection and the form of parasitism they have, act as interwoven circulation networks of P. jirovecii.
Collapse
Affiliation(s)
- Anne Totet
- University Hospital, University of Picardy, Amiens, France
| | | | | | | | | | | | | | - Gilles Nevez
- University Hospital, University of Picardy, Amiens, France
| |
Collapse
|
27
|
Crothers K, Huang L, Morris A, Fox M, Groner G, Turner JR, Merrifield C, Eiser S, Friedly J, Gravari E, Zucchi P, Beard CB. Pneumocystis dihydropteroate synthase mutations in patients with Pneumocystis pneumonia who are newly diagnosed with HIV infection. J Eukaryot Microbiol 2004; 50 Suppl:609-10. [PMID: 14736181 DOI: 10.1111/j.1550-7408.2003.tb00648.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Kristina Crothers
- Division of Pulmonary and Critical Care Medicine and Positive Health Program, San Francisco General Hospital, University of California San Francisco, San Francisco, CA 94110, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Costa MC, Gaspar J, Ribeiro C, Antunes F, Matos O. Dihydropteroate synthase (DHPS) genotyping by PCR-RFLP analysis of Pneumocystis jirovecii repeated isolates from HIV-infected patients: a preliminary study. J Eukaryot Microbiol 2004; 50 Suppl:607-8. [PMID: 14736180 DOI: 10.1111/j.1550-7408.2003.tb00647.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marina Célia Costa
- Unidade de Protozoários Oportunistas/VIH e outras Protozooses, UPMM, Instituto de Higiene e Medicina Tropical, Lisboa, Portugal.
| | | | | | | | | |
Collapse
|
29
|
Costa MC, Helweg-Larsen J, Lundgren B, Antunes F, Matos O. Mutations in the dihydropteroate synthase gene of Pneumocystis jiroveci isolates from Portuguese patients with Pneumocystis pneumonia. Int J Antimicrob Agents 2003; 22:516-20. [PMID: 14602371 DOI: 10.1016/s0924-8579(03)00122-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The aim of this study was to evaluate the frequency of mutations of the P. jiroveci dihydropteroate synthase (DHPS) gene in an immunocompromised Portuguese population and to investigate the possible association between DHPS mutations and sulpha exposure. In the studied population, DHPS gene mutations were not significantly more frequent in patients exposed to sulpha drugs compared with patients not exposed (P=0.390). The results of this study suggest that DHPS gene mutations are frequent in the Portuguese immunocompromised population but do not seem associated with previous sulpha exposure. These results are consistent with the possibility of an incidental acquisition and transmission of P. jiroveci mutant types, either by person to person transmission or from an environmental source.
Collapse
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, Rua da Junqueira 96, 1349-008 Lisbon, Portugal.
| | | | | | | | | |
Collapse
|
30
|
Abstract
Antimicrobial prophylaxis and highly active antiretroviral therapy have changed the epidemiology and impact of pulmonary infection in patients infected with the human immunodeficiency virus (HIV). However, pulmonary infection remains a significant contributor to the morbidity and mortality of such patients. Bacterial pneumonia and tuberculosis remain common lung infections in this setting, especially where appropriate prophylaxis is unavailable or when compliance with such therapy is poor. Pneumonia related to Pneumocystis carinii also remains a significant problem, especially as a presenting illness in patients not yet known to be infected with HIV. Recrudescence of "treated" infection as a manifestation of the immune reconstitution syndrome may become more commonly encountered as more patients are treated with highly active therapy.
Collapse
MESH Headings
- AIDS-Related Opportunistic Infections/diagnosis
- AIDS-Related Opportunistic Infections/drug therapy
- AIDS-Related Opportunistic Infections/epidemiology
- Anti-Bacterial Agents
- Antiretroviral Therapy, Highly Active/methods
- Antitubercular Agents/administration & dosage
- Drug Therapy, Combination
- Female
- Humans
- Incidence
- Male
- Pneumonia, Mycoplasma/diagnosis
- Pneumonia, Mycoplasma/drug therapy
- Pneumonia, Mycoplasma/epidemiology
- Pneumonia, Pneumocystis/diagnosis
- Pneumonia, Pneumocystis/drug therapy
- Pneumonia, Pneumocystis/epidemiology
- Prognosis
- Risk Assessment
- Severity of Illness Index
- Survival Analysis
- Tuberculosis, Pulmonary/diagnosis
- Tuberculosis, Pulmonary/drug therapy
- Tuberculosis, Pulmonary/epidemiology
- United States/epidemiology
Collapse
Affiliation(s)
- Armand J Wolff
- Division of Pulmonary, Critical Care, and Sleep Medicine Georgetown University Medical Center Washington, DC 20007, USA
| | | |
Collapse
|
31
|
Latouche S, Lacube P, Maury E, Bolognini J, Develoux M, Girard PM, Godet C, Lebrette MG, Mayaud C, Guillot J, Roux P. Pneumocystisjiroveciidihydropteroate synthase genotypes in French patients with pneumocystosis: a 1998–2001 prospective study. Med Mycol 2003; 41:533-7. [PMID: 14725329 DOI: 10.1080/13693780310001615394] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Dihydropteroate synthase gene (DHPS) mutations at codons 55 and 57 have been associated with sulfa/sulfone resistance in Pneumocystis jirovecii strains from patients who previously received prophylaxis. To evaluate the prevalence of these mutations, a portion of P. jirovecii DHPS gene was analysed using PCR combined with restriction fragment length polymorphism (RFLP) analysis in 92 bronchoalveolar fluid samples collected between January 1998 and September 2001 from French patients with pulmonary pneumocystosis (PCP). Seventy-six samples contained the wild-type DHPS genotype (82.6%) and 16 contained a mutant genotype (17.4%). Twelve out of the 16 isolates with a mutant DHPS genotype corresponded to patients who had never received sulfa or sulfone prophylaxis, suggesting that DHPS mutants may be acquired de novo. There was no significant difference in favourable or adverse outcome in PCP caused by the wild or mutant DHPS genotypes (P = 0.34).
Collapse
Affiliation(s)
- S Latouche
- Service de Parasitologie-Mycologie, UFR Saint-Antoine, Paris, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Ulrich CM, Robien K, Sparks R. Pharmacogenetics and folate metabolism -- a promising direction. Pharmacogenomics 2002; 3:299-313. [PMID: 12052139 DOI: 10.1517/14622416.3.3.299] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Folate metabolism is the target of two major drug groups: folate antagonists (e.g., methotrexate) and thymidylate synthase inhibitors (for example, 5-fluorouracil). These agents are widely used in cancer chemotherapy, as treatment for rheumatoid arthritis, and for other conditions. The administration of these drugs in cancer chemotherapy can induce a state of acute folate depletion with sometimes life-threatening toxic sequelae. Recent studies suggest that polymorphisms in folate-metabolizing enzymes may modify the therapeutic effectiveness and toxicity of drugs targeting folate metabolism. This review briefly summarizes major drugs targeting the folate pathway and describes common polymorphisms in folate-metabolizing enzymes and transport proteins. Pharmacogenetic studies investigating the relevance of these polymorphisms with respect to patients' response to antifolate chemotherapeutic agents are discussed. Investigating genetic variability in folate metabolism in the framework of pharmacogenetics is a promising field. Findings to date illustrate the potential for targeting therapy based on patients' genotypes with improved outcomes and reduced toxicity.
Collapse
Affiliation(s)
- Cornelia M Ulrich
- Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, MP-900, Seattle, WA 98109-1024, USA.
| | | | | |
Collapse
|