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ABSTRACT: Expression microarray analysis of C. glabrata following phagocytosis by human neutrophils was performed and compared with results from C. glabrata incubated under conditions of carbohydrate or nitrogen deprivation. Twenty genes were selected to represent the major cell processes altered by phagocytosis or nutrient deprivation. Quantitative real-time PCR (qRT-PCR) with TaqMan® chemistry was used to assess expression of the same genes in spleens of mice infected intravenously with Candida glabrata. The results in spleen closely paralleled gene expression in neutrophils or following carbohydrate deprivation. Fungal cells responded by upregulating alternative energy sources through gluconeogenesis, glyoxylate cycle and long chain fatty acid metabolism. Autophagy was likely employed to conserve intracellular resources. Aspartyl protease upregulation occurred and may represent defense against attacks on cell wall integrity. Down regulated genes were in the pathways of protein and ergosterol synthesis. Upregulation of the sterol transport gene, AUS1, suggested that murine cholesterol may have been used to replace ergosterol, as has been reported in vitro. C. glabrata in spleens of gp91(phox-/-) knock-out mice with reduced oxidative phagocyte defenses were grossly similar although with a reduced level of response. These results are consistent with reported results of other fungi responding to phagocytosis, indicating that a rapid shift in metabolism is required for growth in a carbohydrate-limited intracellular environment.
Infection and immunity 02/2013; · 4.21 Impact Factor
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ABSTRACT: The opportunistic yeast pathogen Candida glabrata is recognized for its ability to acquire resistance during prolonged treatment with azole antifungals (5). Resistance to azoles is largely mediated by the transcription factor PDR1, resulting in the upregulation of ATP-binding cassette (ABC) transporter proteins and drug efflux. Studies in the related yeast Saccharomyces cerevisiae have shown Pdr1p forms a heterodimer with another transcription factor, Stb5p. In C. glabrata the ORF designated CAGL0I02552g has 38.8% amino acid identity with STB5 (YHR178w), and shares an N-terminal Zn(2)Cys(6) binuclear cluster domain and a fungal specific transcriptional factor domain, prompting us to test for homologous function and a possible role in azole resistance. Complementation of Δyhr178w (Δstb5) with CAGL0I02552g resolved the increased sensitivity to cold, hydrogen peroxide and caffeine of the mutant, for which reason we designated CAGl0I02552g as CgSTB5. Overexpression of CgSTB5 in C. glabrata repressed azole resistance, whereas deletion of CgSTB5 caused a modest increase in resistance.. Expression analysis found that CgSTB5 shares many of the same transcriptional targets as CgPDR1 but, unlike the latter, is a negative regulator of pleiotropic drug resistance, including the ABC transporter genes CDR1, PDH1, and YOR1.
Antimicrobial Agents and Chemotherapy 12/2012; · 4.84 Impact Factor
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Andrew H Limper,
Kenneth S Knox,
George A Sarosi,
Neil M Ampel, John E Bennett,
Antonino Catanzaro,
Scott F Davies,
William E Dismukes,
Chadi A Hage,
Kieren A Marr,
Christopher H Mody,
John R Perfect,
David A Stevens
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ABSTRACT: With increasing numbers of immune-compromised patients with malignancy, hematologic disease, and HIV, as well as those receiving immunosupressive drug regimens for the management of organ transplantation or autoimmune inflammatory conditions, the incidence of fungal infections has dramatically increased over recent years. Definitive diagnosis of pulmonary fungal infections has also been substantially assisted by the development of newer diagnostic methods and techniques, including the use of antigen detection, polymerase chain reaction, serologies, computed tomography and positron emission tomography scans, bronchoscopy, mediastinoscopy, and video-assisted thorascopic biopsy. At the same time, the introduction of new treatment modalities has significantly broadened options available to physicians who treat these conditions. While traditionally antifungal therapy was limited to the use of amphotericin B, flucytosine, and a handful of clinically available azole agents, current pharmacologic treatment options include potent new azole compounds with extended antifungal activity, lipid forms of amphotericin B, and newer antifungal drugs, including the echinocandins. In view of the changing treatment of pulmonary fungal infections, the American Thoracic Society convened a working group of experts in fungal infections to develop a concise clinical statement of current therapeutic options for those fungal infections of particular relevance to pulmonary and critical care practice. This document focuses on three primary areas of concern: the endemic mycoses, including histoplasmosis, sporotrichosis, blastomycosis, and coccidioidomycosis; fungal infections of special concern for immune-compromised and critically ill patients, including cryptococcosis, aspergillosis, candidiasis, and Pneumocystis pneumonia; and rare and emerging fungal infections.
American Journal of Respiratory and Critical Care Medicine 01/2011; 183(1):96-128. · 11.08 Impact Factor
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ABSTRACT: DNA microarrays were used to analyze Candida glabrata oropharyngeal isolates from seven hematopoietic stem cell transplant recipients whose isolates developed azole resistance while the recipients received fluconazole prophylaxis. Transcriptional profiling of the paired isolates revealed 19 genes upregulated in the majority of resistant isolates compared to their paired susceptible isolates. All seven resistant isolates had greater than 2-fold upregulation of C. glabrata PDR1 (CgPDR1), a master transcriptional regulator of the pleiotropic drug resistance (PDR) network, and all seven resistant isolates showed upregulation of known CgPDR1 target genes. The altered transcriptome can be explained in part by the observation that all seven resistant isolates had acquired a single nonsynonymous mutation in their CgPDR1 open reading frame. Four mutations occurred in the regulatory domain (L280P, L344S, G348A, and S391L) and one in the activation domain (G943S), while two mutations (N764I and R772I) occurred in an undefined region. Association of azole resistance and the CgPDR1 mutations was investigated in the same genetic background by introducing the CgPDR1 sequences from one sensitive isolate and five resistant isolates into a laboratory azole-hypersusceptible strain (Cgpdr1 strain) via integrative transformation. The Cgpdr1 strain was restored to wild-type fluconazole susceptibility when transformed with CgPDR1 from the susceptible isolate but became resistant when transformed with CgPDR1 from the resistant isolates. However, despite the identical genetic backgrounds, upregulation of CgPDR1 and CgPDR1 target genes varied between the five transformants, independent of the domain locations in which the mutations occurred. In summary, gain-of-function mutations in CgPDR1 contributed to the clinical azole resistance, but different mutations had various degrees of impact on the CgPDR1 target genes.
Antimicrobial Agents and Chemotherapy 08/2010; 54(8):3308-17. · 4.84 Impact Factor
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ABSTRACT: Nosocomial outbreaks of Legionnaires disease have been linked to contaminated water in hospitals. Immunocompromised patients are particularly vulnerable and, when infected, have a high mortality rate. We report the investigation of a cluster of cases of nosocomial pneumonia attributable to Legionella pneumophila serogroup 1 that occurred among patients on our stem cell transplantation unit.
We conducted a record review to identify common points of potential exposure, followed by environmental and water sampling for Legionella species from those sources. We used an air sampler to in an attempt to detect aerosolized Legionella and pulsed-field gel electrophoresis to compare clinical and environmental isolates.
The most likely sources identified were the water supply in the patients' rooms and a decorative fountain in the radiation oncology suite. Samples from the patients' rooms did not grow Legionella species. Cultures of the fountain, which had been restarted 4 months earlier after being shut off for 5 months, yielded L. pneumophila serogroup 1. The isolates from both patients and the fountain were identical by pulsed-field gel electrophoresis. Both patients developed pneumonia within 10 days of completing radiation therapy, and each reported having observed the fountain at close range. Both patients' infections were identified early and treated promptly, and both recovered.
This cluster was caused by contamination of a decorative fountain despite its being equipped with a filter and ozone generator. Fountains are a potential source of nosocomial Legionnaires disease despite standard maintenance and sanitizing measures. In our opinion, fountains present unacceptable risk in hospitals serving immunocompromised patients.
Infection Control and Hospital Epidemiology 09/2009; 30(8):764-8. · 3.67 Impact Factor
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John E Bennett
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ABSTRACT: The career that this symposium honours, that of Ben E. de Pauw, MD, PhD, could be said to have begun in 1970 upon his graduation from the University of Amsterdam. However, it was his move to Nijmegen in 1975 to finish his PhD studies that really began the career in which he forged expertise in haematology, oncology, immunology and infectious diseases into one spectacular career that resulted in more than 200 publications.
Journal of Antimicrobial Chemotherapy 06/2009; 63 Suppl 1:i23-6. · 5.07 Impact Factor
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Brahm H Segal,
Raoul Herbrecht,
David A Stevens,
Luis Ostrosky-Zeichner,
Jack Sobel,
Claudio Viscoli,
Thomas J Walsh,
Johan Maertens,
Thomas F Patterson,
John R Perfect, [......],
Maria Anna Viviani,
Jacques Bille,
Nikolaos G Almyroudis,
L Joseph Wheat,
Wolfgang Graninger,
Eric J Bow,
Steven M Holland,
Bart-Jan Kullberg,
William E Dismukes,
Ben E De Pauw
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ABSTRACT: Invasive fungal diseases (IFDs) have become major causes of morbidity and mortality among highly immunocompromised patients. Authoritative consensus criteria to diagnose IFD have been useful in establishing eligibility criteria for antifungal trials. There is an important need for generation of consensus definitions of outcomes of IFD that will form a standard for evaluating treatment success and failure in clinical trials. Therefore, an expert international panel consisting of the Mycoses Study Group and the European Organization for Research and Treatment of Cancer was convened to propose guidelines for assessing treatment responses in clinical trials of IFDs and for defining study outcomes. Major fungal diseases that are discussed include invasive disease due to Candida species, Aspergillus species and other molds, Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitis. We also discuss potential pitfalls in assessing outcome, such as conflicting clinical, radiological, and/or mycological data and gaps in knowledge.
Clinical Infectious Diseases 09/2008; 47(5):674-83. · 9.15 Impact Factor
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ABSTRACT: As part of a prospective natural history cohort study of voriconazole toxicity, we describe the characteristics of 12 of 72 voriconazole-treated patients who experienced hallucinations from March 2006 through November 2007. Hallucinations associated with voriconazole use are not uncommon. Doctors should be aware of this complication, and the recipients of the drug should be reassured that the hallucinations are an effect of the drug.
Clinical Infectious Diseases 08/2008; 47(1):e7-e10. · 9.15 Impact Factor
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Dimitrios I Zonios,
Judith Falloon, John E Bennett,
Pamela A Shaw,
Doreen Chaitt,
Michael W Baseler,
Joseph W Adelsberger,
Julia A Metcalf,
Michael A Polis,
Stephen J Kovacs,
Joseph A Kovacs,
Richard T Davey,
H Clifford Lane,
Henry Masur,
Irini Sereti
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ABSTRACT: Idiopathic CD4(+) lymphocytopenia (ICL) is a rare non-HIV-related syndrome with unclear natural history and prognosis. This prospective natural history cohort study describes the clinical course, CD4 T lymphocyte kinetics, outcome, and prognostic factors of ICL. Thirty-nine patients (17 men, 22 women) 25 to 85 years old with ICL were evaluated between 1992 and 2006, and 36 were followed for a median of 49.5 months. Cryptococcal and nontuberculous mycobacterial infections were the major presenting opportunistic infections. Seven patients presented with no infection. In 32, CD4 T-cell counts remained less than 300/mm(3) throughout the study period and in 7 normalized after an average of 31 months. Overall, 15 (41.6%) developed an opportunistic infection in follow-up, 5 (13.8%) of which were "AIDS-defining clinical conditions," and 4 (11.1%) developed autoimmune diseases. Seven patients died, 4 from ICL-related opportunistic infections, within 42 months after diagnosis. Immunologic analyses revealed increased activation and turnover in CD4 but not CD8 T lymphocytes. CD8 T lymphocytopenia (< 180/mm(3)) and the degree of CD4 T cell activation (measured by HLA-DR expression) at presentation were associated with adverse outcome (opportunistic infection-related death; P = .003 and .02, respectively).
Blood 07/2008; 112(2):287-94. · 9.90 Impact Factor
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Ben De Pauw,
Thomas J Walsh,
J Peter Donnelly,
David A Stevens,
John E Edwards,
Thierry Calandra,
Peter G Pappas,
Johan Maertens,
Olivier Lortholary,
Carol A Kauffman, [......],
John R Perfect,
Angela Restrepo,
Markus Ruhnke,
Brahm H Segal,
Jack D Sobel,
Tania C Sorrell,
Claudio Viscoli,
John R Wingard,
Theoklis Zaoutis, John E Bennett
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ABSTRACT: Invasive fungal diseases are important causes of morbidity and mortality. Clarity and uniformity in defining these infections are important factors in improving the quality of clinical studies. A standard set of definitions strengthens the consistency and reproducibility of such studies.
After the introduction of the original European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group definitions, advances in diagnostic technology and the recognition of areas in need of improvement led to a revision of this document. The revision process started with a meeting of participants in 2003, to decide on the process and to draft the proposal. This was followed by several rounds of consultation until a final draft was approved in 2005. This was made available for 6 months to allow public comment, and then the manuscript was prepared and approved.
The revised definitions retain the original classifications of "proven," "probable," and "possible" invasive fungal disease, but the definition of "probable" has been expanded, whereas the scope of the category "possible" has been diminished. The category of proven invasive fungal disease can apply to any patient, regardless of whether the patient is immunocompromised, whereas the probable and possible categories are proposed for immunocompromised patients only.
These revised definitions of invasive fungal disease are intended to advance clinical and epidemiological research and may serve as a useful model for defining other infections in high-risk patients.
Clinical Infectious Diseases 07/2008; 46(12):1813-21. · 9.15 Impact Factor
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ABSTRACT: This is a comprehensive, clinically oriented review of the four commercially available triazoles: fluconazole, itraconazole, voriconazole, and posaconazole. Emphasis is placed in pharmacology, drug interactions, adverse events, antifungal activity, and the evolving perspective of their clinical use. Key clinical trials are briefly discussed, and specific drug indications summarized. Fluconazole remains a valuable low-cost choice for the treatment of various fungal infections, including candidiasis and cryptococcosis. It has relatively few drug interactions and is safe but lacks activity against filamentous fungi. The use of itraconazole is historically plagued by erratic bioavailability of the oral capsule, improved with the oral solution. Drug interactions are numerous. Itraconazole exhibits significant activity against Aspergillus and the endemic fungi. Voriconazole has revolutionized the treatment of aspergillosis in severely immunocompromised patients, but its use is compromised by complicated pharmacokinetics, notable drug interactions, and relatively significant adverse events. Finally, posaconazole is the last addition to the azole armamentarium with extended antifungal spectrum, significant activity against the zygomycetes, and, apparently, optimal safety profile. Posaconazole has a significant role for the prophylaxis of invasive fungal infections in severely immunocompromised patients. Multiple daily dosing, a need for fatty foods for absorption, and absence of an intravenous formulation restrict its use to selected populations.
Seminars in Respiratory and Critical Care Medicine 05/2008; 29(2):198-210. · 2.43 Impact Factor
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ABSTRACT: We reviewed the cases of 11 patients with cryptococcosis and idiopathic CD4 lymphocytopenia (ICL) referred to our institution in the previous 12 years, as well as 42 similar cases reported in the literature, to assess the characteristics of the infection in this population. Cryptococcosis in 53 patients with ICL had features in common with cryptococcosis in previously normal patients. ICL patients had a slight male predominance (1.2:1) and a median age of presentation of 41 years (range, 4.5-85 yr). Initial cerebrospinal fluid findings showed glucose below 40 mg/dL in 60% of the patients, a median pleocytosis of 59 white blood cells/mm (range, 0-884), and protein of 156 mg/dL (range, 25-402 mg/dL). The median CD4 count at diagnosis of ICL and at the last available measurement was 82 (range, 7-292) and 132 (range, 13-892) cells/mm, respectively, for an average follow-up of 32 months in 46 patients. Unlike previously normal patients with cryptococcosis, those with ICL had an excess incidence of dermatomal zoster (7 episodes in 46 ICL cases). Pneumocystis pneumonia was rare (1 case), casting doubt on the need for prophylaxis in patients with ICL. A favorable outcome (cured or improved) may be more common in ICL patients than in previously normal patients with cryptococcal meningitis and no predisposing factors. Identification of ICL in patients who were apparently normal before the onset of cryptococcosis appears to be useful because it predicts a favorable outcome. Patients with cryptococcal infection and ICL have an increased likelihood of developing dermatomal zoster. The long-term follow-up of these patients offers some reassurance regarding favorable prognosis.
Medicine 04/2007; 86(2):78-92. · 4.35 Impact Factor
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Reginald E Greene,
Haran T Schlamm,
Jörg-W Oestmann,
Paul Stark,
Christine Durand,
Olivier Lortholary,
John R Wingard,
Raoul Herbrecht,
Patricia Ribaud,
Thomas F Patterson,
Peter F Troke,
David W Denning, John E Bennett,
Ben E de Pauw,
Robert H Rubin
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ABSTRACT: Computed tomography (CT) of the chest may be used to identify the halo sign, a macronodule surrounded by a perimeter of ground-glass opacity, which is an early sign of invasive pulmonary aspergillosis (IPA). This study analyzed chest CT findings at presentation from a large series of patients with IPA, to assess the prevalence of these imaging findings and to evaluate the clinical utility of the halo sign for early identification of this potentially life-threatening infection.
Baseline chest CT imaging findings from 235 patients with IPA who participated in a previously published study were systematically analyzed. To evaluate the clinical utility of the halo sign for the early identification and treatment of IPA, we compared response to treatment and survival after 12 weeks of treatment in 143 patients who presented with a halo sign and in 79 patients with other imaging findings.
At presentation, most patients (94%) had > or =1 macronodules, and many (61%) also had halo signs. Other imaging findings at presentation, including consolidations (30%), infarct-shaped nodules (27%), cavitary lesions (20%), and air-crescent signs (10%), were less common. Patients presenting with a halo sign had significantly better responses to treatment (52% vs. 29%; P<.001) and greater survival to 84 days (71% vs. 53%; P<.01) than did patients who presented with other imaging findings.
Most patients presented with a halo sign and/or a macronodule in this large imaging study of IPA. Initiation of antifungal treatment on the basis of the identification of a halo sign by chest CT is associated with a significantly better response to treatment and improved survival.
Clinical Infectious Diseases 03/2007; 44(3):373-9. · 9.15 Impact Factor
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ABSTRACT: Transcriptional regulation in response to environmental challenges is crucial for survival of many organisms. In this study, we characterized structural and functional properties of CgAP1, a Saccharomyces cerevisiae YAP1 ortholog, which encodes a transcription factor involved in various stress responses. Deletion of CgAP1 led to decreased resistance to hydrogen peroxide, 4-nitroquinoline-N-oxide (4-NQO), benomyl, and cadmium chloride, which could be fully recovered by reintroduction of an intact CgAP1. CgAP1 was shown to function in S. cerevisiae as it restored the drug resistance of the yap1 mutant. Moreover, overexpression of CgAP1 in a S. cerevisiae wild-type strain increased its resistance to cycloheximide, 1,10-phenanthroline, 4-NQO, and fluconazole. Overexpression of CgAP1 also phenotypically suppressed the drug sensitivity of two Yap1p-regulated transporter mutants, Deltaatr1 and Deltaflr1, to diamide, 4-NQO, and cadmium. Northern blot analysis indicated that Cgap1p regulates the benomyl-induced expression of CgFLR1, a homolog of S. cerevisiae FLR1, which encodes a transporter of the major facilitator superfamily. In contrast to the S. cerevisiae flr1 mutant, deletion of CgFLR1 in C. glabrata only resulted in increased sensitivity to benomyl, diamide, and menadione, but not 4-NQO, cycloheximide, or fluconazole. Taken together, this report demonstrated that CgAP1 plays a critical role in response to various stresses in C. glabrata and reduces the stress through transcriptional activation of its target genes including CgFLR1.
Gene 02/2007; 386(1-2):63-72. · 2.34 Impact Factor
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John E Bennett
New England Journal of Medicine 10/2006; 355(11):1154-9. · 53.30 Impact Factor
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John E Bennett
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ABSTRACT: Randomized trials in invasive aspergillosis have evolved over the past decade. Definitions of disease now include specifics of the underlying disease and how this affects interpretation of certain tests, including high resolution computed tomography and smears or cultures of sputum and bronchoalveolar lavage. Study hypotheses have changed from underpowered superiority trials to adequately powered noninferiority trials. Consensus building between Europe and North America has allowed trials to be conducted with the same protocol in both regions, thereby increasing study enrollment. In aggregate, the following outcomes can be drawn from randomized trials: (i) Liposomal amphotericin B is possibly superior to conventional amphotericin B at 14 days and less toxic. Whether the dose of liposomal amphotericin is 1 or 4 mg/kg daily is not as important as other factors in determining outcome of possible aspergillosis; (ii) amphotericin B colloidal dispersion is less nephrotoxic but has more acute infusion-related reactions than conventional amphotericin B; (iii) starting treatment with voriconazole is superior to starting with conventional amphotericin B. In an era of increasing cost containment, it will be the randomized trials that provide the clinician with the information needed to avoid inappropriate use of expensive drugs and drug combinations.
Medical Mycology 10/2006; 44 Suppl 1:S305-8. · 2.46 Impact Factor
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ABSTRACT: Candida glabrata KRE29 is an ortholog of Saccharomyces cerevisiae KRE29. S. cerevisiae Kre29p has been identified by affinity purification as a subunit of the Smc5-Smc6 complex, which is required for DNA repair and chromosome segregation. However, mutant phenotypes of S. cerevisiae KRE29 have not been well characterized and none of its orthologs' functions has been reported. Here we report phenotypic characteristics of a C. glabrata kre29 deletant. The absence of C. glabrata Kre29p resulted in decreased viability, exhibiting cell cycle arrest between late S-phase and metaphase even under normal growth conditions, and also caused an increase of plasmid loss rate, implying that Kre29p is required for mitotic chromosome transmission fidelity. The deletant showed increased sensitivity to high temperature as well as to DNA damaging agents including UV, gamma ray, 4-nitroquinoline-1-oxide and methyl methanesulfonate, and the phenotypes were restored in the KRE29 reintegrant. Consistent with the Deltakre29 phenotypes, a Kre29p-GFP fusion protein was located in the nucleus. Furthermore, Kre29p-GFP became concentrated and formed distinct foci after exposure to 4-nitroquinoline-1-oxide. These results suggest the involvement of C. glabrata Kre29p in DNA repair. To our knowledge, this is the first report addressing a cellular protein involved in DNA repair in C. glabrata.
Current Genetics 08/2006; 50(1):11-22. · 2.56 Impact Factor
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ABSTRACT: Candida glabrata, a yeast with intrinsically low susceptibility to azoles, frequently develops increased azole resistance during prolonged treatment. Transposon mutagenesis revealed that disruption of CgPDR1 resulted in an 8- to 16-fold increase in fluconazole susceptibility of C. glabrata. CgPDR1 is a homolog of Saccharomyces cerevisiae PDR1, which encodes a transcriptional regulator of multidrug transporters. Northern blot analyses indicated that CgPDR1 regulated both constitutive and drug-induced expression of CgCDR1, a multidrug transporter gene. In agreement with the Northern analysis, the Cgpdr1 mutant had increased rhodamine accumulation, in contrast to the decreased accumulation in the CgPDR1-overexpressing strain. Northern analyses also indicated the importance of CgPDR1 in fluconazole resistance arising during therapy. Two clinically resistant isolates had higher expression of CgPDR1 and CgCDR1 compared to their paired susceptible isolates. Integrative transformation of CgPDR1 from the two resistant isolates converted the Cgpdr1 mutant into azole-resistant strains with upregulated CgPDR1 expression. Two different amino acid substitutions, W297S in one isolate and F575L in the other, accounted for the upregulated CgPDR1 expression and the resistance. Finally, CgPDR1 was shown to be required for the azole resistance due to mitochondrial deficiency. Thus, CgPDR1 encodes a transcriptional regulator of a pleiotropic drug resistance network and contributes to the azole resistance of clinical isolates and petite mutants.
Antimicrobial Agents and Chemotherapy 05/2006; 50(4):1384-92. · 4.84 Impact Factor
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ABSTRACT: Candida albicans ERG3 encodes a sterol C5,6-desaturase which is essential for synthesis of ergosterol. Defective sterol C5,6 desaturation has been considered to be one of the azole resistance mechanisms in this species. However, the clinical relevance of this resistance mechanism is still unclear. In this study, we created a C. albicans erg3/erg3 mutant by the "Ura-blaster" method and confirmed the expected azole resistance using standard in vitro testing and the presence of ergosta-7,22-dien-3beta-ol instead of ergosterol. For in vivo studies, a wild-type URA3 was placed back into its native locus in the erg3 homozygote to avoid positional effects on URA3 expression. Defective hyphal formation of the erg3 homozygote was observed not only in vitro but in kidney tissues. A marked attenuation of virulence was shown by the longer survival and the lower kidney burdens of mice inoculated with the reconstituted Ura+ erg3 homozygote relative to the control. To assess fluconazole efficacy in a murine model of disseminated candidiasis, inoculum sizes of the control and the erg3 homozygote were chosen which provided a similar organ burden. Under these conditions, fluconazole was highly effective in reducing the organ burden in both groups. This study demonstrates that an ERG3 mutation causing inactivation of sterol C5,6-desaturase cannot confer fluconazole resistance in vivo by itself regardless of resistance measured by standard in vitro testing. The finding questions the clinical significance of this resistance mechanism.
Antimicrobial Agents and Chemotherapy 03/2006; 50(2):580-6. · 4.84 Impact Factor
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Thomas F Patterson,
Helen W Boucher,
Raoul Herbrecht,
David W Denning,
Olivier Lortholary,
Patricia Ribaud,
Robert H Rubin,
John R Wingard,
Ben DePauw,
Haran T Schlamm,
Peter Troke, John E Bennett
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ABSTRACT: In a previous randomized trial of voriconazole versus amphotericin B deoxycholate for primary therapy of invasive aspergillosis, voriconazole demonstrated superior efficacy and better survival. In that trial, treatment with voriconazole or amphotericin B deoxycholate could be followed with other licensed antifungal therapies (OLAT). Here, we report the impact of OLAT on the outcome of patients with invasive aspergillosis.
Data on dose, duration, and the reason for switching to the first OLAT were analyzed, and outcome at week 12 was assessed.
Fewer patients in the voriconazole group (52 [36%] of 144) switched to OLAT, compared with patients in the amphotericin B deoxycholate group (107 [80%] of 133). Lipid formulations of amphotericin B were the most common OLAT (38% of patients). Switches were made because of intolerance or insufficient response in 70% for patients in the amphotericin B deoxycholate group, compared with 24% of patients in the voriconazole group. Favorable responses to OLAT in the amphotericin B deoxycholate group occurred in only 19% of patients with initial insufficient response and 38% of patients with intolerance. Salvage therapy with a lipid formulation of amphotericin B after initial treatment with amphotericin B deoxycholate was successful for only 30% of patients (14 of 47). Treatment success among patients randomized to receive amphotericin B, including those whose treatment was switched to OLAT, was 32%, compared with 55% among patients who received voriconazole alone (P<.001).
This study highlights the limited efficacy of salvage antifungal therapy, including therapy with lipid formulations of amphotericin B, and demonstrates the importance of effective initial therapy in invasive aspergillosis.
Clinical Infectious Diseases 12/2005; 41(10):1448-52. · 9.15 Impact Factor
