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1.
J Fungi (Basel) ; 7(4)2021 Mar 29.
Article in English | MEDLINE | ID: mdl-33805369

ABSTRACT

Fungal keratitis is difficult to treat, especially Fusarium keratitis. In vitro studies show that chlorhexidine could be an interesting option as monotherapy. We describe a case series of four patients (four eyes) with Fusarium keratitis at Radboud University Medical Center (Nijmegen, the Netherlands). The patients were treated with chlorhexidine 0.02% eye drops. The in vitro activity of eight antifungals and chlorhexidine was determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. We also reviewed the literature on the use of chlorhexidine in the treatment of fungal keratitis. Topical chlorhexidine was well tolerated, and all patients showed complete resolution of the keratitis upon treatment with chlorhexidine. A PubMed search of the available literature was conducted (last search 8 March 2020) and yielded two randomized clinical trials (natamycin versus chlorhexidine) and one case report addressing the treatment of fungal keratitis with chlorhexidine. Chlorhexidine was found to be safe with regard to toxicity and to be superior to natamycin in the clinical trials. Chlorhexidine showed in vitro fungicidal activity against Fusarium and clinical effectiveness in our cases, supporting further clinical evaluation. Advantages of chlorhexidine are its topical application, its general availability, its low costs, its broad-spectrum activity, and its fungicidal mechanism of action at low concentrations.

3.
J Clin Microbiol ; 58(12)2020 11 18.
Article in English | MEDLINE | ID: mdl-32938733

ABSTRACT

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based species identification has found its place in many clinical routine diagnostic laboratories over the past years, allowing significantly reduced turnaround times and high-precision results. With regard to MALDI-TOF MS for filamentous fungi, here, we discuss different approaches for sample processing and growth conditions before analysis. In particular, we review the performances of different commercially available databases as well as the potential of complementary (self-constructed) in-house databases.


Subject(s)
Clinical Laboratory Services , Fungi , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
4.
J Fungi (Basel) ; 5(4)2019 Oct 07.
Article in English | MEDLINE | ID: mdl-31591307

ABSTRACT

BACKGROUND: Candida auris is a yeast that is causing nosocomial outbreaks in healthcare facilities around the world. There is a risk of the misidentification of C. auris with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-when libraries are used that lack C. auris spectra, or when conventional biochemical methods are used. METHODS: We conducted an external quality assessment to evaluate the ability of Dutch clinical microbiological laboratories to identify C. auris, and to raise awareness about the risk of misidentification. RESULTS: 35/47 participating laboratories were able to identify C. auris correctly. Only 2/14 labs that potentially misidentified C. auris with their primary identification methods specified that they would perform additional tests to exclude C. auris when appropriate. 45/47 labs used MALDI-TOF MS systems to identify Candida species. CONCLUSIONS: There was a lack of awareness about the potential misidentification of C. auris in many labs that used MALDI-TOF MS with libraries that lacked C. auris spectra, and labs that used Vitek 2. However, as the currently available MALDI-TOF MS libraries in The Netherlands contain several C. auris spectra, we expect that currently almost all participating laboratories are able to identify C. auris correctly, as 45/47 participating laboratories use MALDI-TOF MS as their primary yeast identification method.

5.
Article in English | MEDLINE | ID: mdl-31182529

ABSTRACT

Fungal keratitis is a common but severe eye infection in tropical and subtropical areas of the world. In regions with a temperate climate, the frequency of infection is rising in patients with contact lenses and following trauma. Early and adequate therapy is important to prevent disease progression and loss of vision. The management of Fusarium keratitis is complex, and the optimal treatment is not well defined. We investigated the in vitro activity of chlorhexidine and seven antifungal agents against a well-characterized collection of Fusarium isolates recovered from patients with Fusarium keratitis. The fungus culture collection of the Center of Expertise in Mycology Radboudumc/CWZ was searched for Fusarium isolates that were cultured from cornea scrapings, ocular biopsy specimens, eye swabs, and contact lens fluid containers from patients with suspected keratitis. The Fusarium isolates that were cultured from patients with confirmed keratitis were all identified using conventional and molecular techniques. Antifungal susceptibility testing was performed according to the EUCAST broth microdilution reference method. The antifungal agents tested included amphotericin B, voriconazole, posaconazole, miconazole, natamycin, 5-fluorocytosine, and caspofungin. In addition, the activity of chlorhexidine was determined. The fungal culture collection contained 98 Fusarium isolates of confirmed fungal keratitis cases from 83 Dutch patients and 15 Tanzanian patients. The isolates were collected between 2007 and 2017. Fusarium oxysporum (n = 24, 24.5%) was the most frequently isolated species followed by Fusarium solanisensu stricto (n = 18, 18.4%) and Fusarium petroliphilum (n = 11, 11.2%). Amphotericin B showed the most favorable in vitro inhibition of Fusarium species followed by natamycin, voriconazole, and chlorhexidine, while 5-fluorocytosine, posaconazole, miconazole, and caspofungin showed no relevant inhibiting effect. However, chlorhexidine showed fungicidal activity against 90% of F. oxysporum strains and 100% of the F. solani strains. Our study supports the clinical efficacy of chlorhexidine and therefore warrants its further clinical evaluation for primary therapy of fungal keratitis, particularly in low and middle income countries where fungal keratitis is much more frequent and, currently, antifungal eye drops are often unavailable.


Subject(s)
Antifungal Agents/pharmacology , Chlorhexidine/pharmacology , Fusarium/drug effects , Fusarium/pathogenicity , Keratitis/microbiology , Amphotericin B/pharmacology , Caspofungin/pharmacology , Flucytosine/pharmacology , Fusariosis/microbiology , Humans , Miconazole/pharmacology , Microbial Sensitivity Tests , Natamycin/pharmacology , Triazoles/pharmacology , Voriconazole/pharmacology
6.
Clin Infect Dis ; 68(9): 1463-1471, 2019 04 24.
Article in English | MEDLINE | ID: mdl-30307492

ABSTRACT

BACKGROUND: Triazole resistance is an increasing problem in invasive aspergillosis (IA). Small case series show mortality rates of 50%-100% in patients infected with a triazole-resistant Aspergillus fumigatus, but a direct comparison with triazole-susceptible IA is lacking. METHODS: A 5-year retrospective cohort study (2011-2015) was conducted to compare mortality in patients with voriconazole-susceptible and voriconazole-resistant IA. Aspergillus fumigatus culture-positive patients were investigated to identify patients with proven, probable, and putative IA. Clinical characteristics, day 42 and day 90 mortality, triazole-resistance profiles, and antifungal treatments were investigated. RESULTS: Of 196 patients with IA, 37 (19%) harbored a voriconazole-resistant infection. Hematological malignancy was the underlying disease in 103 (53%) patients, and 154 (79%) patients were started on voriconazole. Compared with voriconazole-susceptible cases, voriconazole resistance was associated with an increase in overall mortality of 21% on day 42 (49% vs 28%; P = .017) and 25% on day 90 (62% vs 37%; P = .0038). In non-intensive care unit patients, a 19% lower survival rate was observed in voriconazole-resistant cases at day 42 (P = .045). The mortality in patients who received appropriate initial voriconazole therapy was 24% compared with 47% in those who received inappropriate therapy (P = .016), despite switching to appropriate antifungal therapy after a median of 10 days. CONCLUSIONS: Voriconazole resistance was associated with an excess overall mortality of 21% at day 42 and 25% at day 90 in patients with IA. A delay in the initiation of appropriate antifungal therapy was associated with increased overall mortality.


Subject(s)
Aspergillus fumigatus/genetics , Autoimmune Diseases/drug therapy , Drug Resistance, Fungal/genetics , Hematologic Neoplasms/drug therapy , Invasive Pulmonary Aspergillosis/drug therapy , Voriconazole/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Antifungal Agents/therapeutic use , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/pathogenicity , Autoimmune Diseases/complications , Autoimmune Diseases/microbiology , Autoimmune Diseases/mortality , Child , Child, Preschool , Female , Hematologic Neoplasms/complications , Hematologic Neoplasms/microbiology , Hematologic Neoplasms/mortality , Humans , Invasive Pulmonary Aspergillosis/complications , Invasive Pulmonary Aspergillosis/microbiology , Invasive Pulmonary Aspergillosis/mortality , Male , Microbial Sensitivity Tests , Middle Aged , Retrospective Studies , Survival Analysis , Time Factors
7.
Article in English | MEDLINE | ID: mdl-28264849

ABSTRACT

Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the species level by analyzing partial ß-tubulin and calmodulin genes. In vitro antifungal susceptibility testing was performed against antifungals using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. In addition, genotyping was performed using a short-tandem-repeat (STR) assay of a panel of six microsatellite markers (A. flavus 2A, 2B, 2C, 3A, 3B, and 3C), in order to determine the genetic variation and the potential relationship between clinical and environmental isolates. The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all isolates were (in increasing order): posaconazole, 0.13 mg/liter; anidulafungin, 0.16 mg/liter; itraconazole, 0.29 mg/liter; caspofungin, 0.42 mg/liter; voriconazole, 0.64 mg/liter; isavuconazole, 1.10 mg/liter; amphotericin B, 3.35 mg/liter; and flucytosine, 62.97 mg/liter. All of the clinical isolates were genetically different. However, an identical microsatellite genotype was found between a clinical isolate and two environmental strains. In conclusion, posaconazole and anidulafungin showed the greatest in vitro activity among systemic azoles and echinocandins, respectively. However, the majority of the A. flavus isolates showed reduced susceptibility to amphotericin B. Antifungal susceptibility of A. flavus was not linked with the clinical or environmental source of isolation. Microsatellite genotyping may suggest an association between clinical and environmental strains, although this requires further investigation.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus flavus , Genetic Variation/genetics , Microsatellite Repeats/genetics , Aspergillosis/microbiology , Aspergillus flavus/drug effects , Aspergillus flavus/genetics , Aspergillus flavus/isolation & purification , Calmodulin/genetics , Genotype , Humans , Microbial Sensitivity Tests , Tubulin/genetics
8.
Article in English | MEDLINE | ID: mdl-27956429

ABSTRACT

Trichophyton schoenleinii is an anthropophilic dermatophyte mainly causing tinea favosa of the scalp in certain regions of the world, especially Africa and Asia. We investigated the in vitro susceptibilities of 55 T. schoenleinii isolates collected over the last 30 years from Iran, Turkey, and China to 12 antifungals using the CLSI broth microdilution method. Our results revealed that terbinafine and ketoconazole were the most potent antifungal agents among those tested, independently of the geographic regions where strains were isolated.


Subject(s)
Antifungal Agents/pharmacology , Tinea Favosa/microbiology , Trichophyton/drug effects , China , Humans , Iran , Ketoconazole/pharmacology , Microbial Sensitivity Tests , Naphthalenes/pharmacology , Terbinafine , Trichophyton/isolation & purification , Turkey
9.
J Clin Microbiol ; 54(11): 2798-2803, 2016 11.
Article in English | MEDLINE | ID: mdl-27605714

ABSTRACT

In a retrospective multicenter study, 102 formalin-fixed paraffin-embedded (FFPE) tissue specimens with histopathology results were tested. Two 4- to 5-µm FFPE tissue sections from each specimen were digested with proteinase K, followed by automated nucleic acid extraction. Multiple real-time quantitative PCR (qPCR) assays targeting the internal transcribed spacer 2 (ITS2) region of ribosomal DNA, using fluorescently labeled primers, was performed to identify clinically important genera and species of Aspergillus, Fusarium, Scedosporium, and the Mucormycetes The molecular identification was correlated with results from histological examination. One of the main findings of our study was the high sensitivity of the automated DNA extraction method, which was estimated to be 94%. The qPCR procedure that was evaluated identified a range of fungal genera/species, including Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger, Fusarium oxysporum, Fusarium solani, Scedosporium apiospermum, Rhizopus oryzae, Rhizopus microsporus, Mucor spp., and Syncephalastrum Fusarium oxysporum and F. solani DNA was amplified from five specimens from patients initially diagnosed by histopathology as having aspergillosis. Aspergillus flavus, S. apiospermum, and Syncephalastrum were detected from histopathological mucormycosis samples. In addition, examination of four samples from patients suspected of having concomitant aspergillosis and mucormycosis infections resulted in the identification of two A. flavus isolates, one Mucor isolate, and only one sample having both R. oryzae and A. flavus Our results indicate that histopathological features of molds may be easily confused in tissue sections. The qPCR assay used in this study is a reliable tool for the rapid and accurate identification of fungal pathogens to the genus and species levels directly from FFPE tissues.


Subject(s)
Aspergillus/isolation & purification , Fusarium/isolation & purification , Mucorales/isolation & purification , Mycoses/diagnosis , Pathology, Molecular/methods , Real-Time Polymerase Chain Reaction/methods , Scedosporium/isolation & purification , Aspergillus/genetics , Automation, Laboratory/methods , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Diagnosis, Differential , Disinfectants , Fixatives , Formaldehyde , Fusarium/genetics , Humans , Mucorales/genetics , Paraffin , Scedosporium/genetics , Specimen Handling/methods , Tissue Fixation
10.
Ann Oncol ; 27(10): 1895-902, 2016 10.
Article in English | MEDLINE | ID: mdl-27502710

ABSTRACT

BACKGROUND: Variable chemotherapy exposure may cause toxicity or lack of efficacy. This study was initiated to validate pharmacokinetically (PK)-guided paclitaxel dosing in patients with advanced non-small-cell lung cancer (NSCLC) to avoid supra- or subtherapeutic exposure. PATIENTS AND METHODS: Patients with newly diagnosed, advanced NSCLC were randomly assigned to receive up to 6 cycles of 3-weekly carboplatin AUC 6 or cisplatin 80 mg/m(2) either with standard paclitaxel at 200 mg/m(2) (arm A) or PK-guided dosing of paclitaxel (arm B). In arm B, initial paclitaxel dose was adjusted to body surface area, age, sex, and subsequent doses were guided by neutropenia and previous-cycle paclitaxel exposure [time above a plasma concentration of 0.05 µM (Tc>0.05)] determined from a single blood sample on day 2. The primary end point was grade 4 neutropenia; secondary end points included neuropathy, radiological response, progression-free survival (PFS) and overall survival (OS). RESULTS: Among 365 patients randomly assigned, grade 4 neutropenia was similar in both arms (19% versus 16%; P = 0.10). Neuropathy grade ≥2 (38% versus 23%, P < 0.001) and grade ≥3 (9% versus 2%, P < 0.001) was significantly lower in arm B, independent of the platinum drug used. The median final paclitaxel dose was significantly lower in arm B (199 versus 150 mg/m(2), P < 0.001). Response rate was similar in arms A and B (31% versus 27%, P = 0.405), as was adjusted median PFS [5.5 versus 4.9 months, hazard ratio (HR) 1.16, 95% confidence interval (CI) 0.91-1.49, P = 0.228] and OS (10.1 versus 9.5 months, HR 1.05, 95% CI 0.81-1.37, P = 0.682). CONCLUSION: PK-guided dosing of paclitaxel does not improve severe neutropenia, but reduces paclitaxel-associated neuropathy and thereby improves the benefit-risk profile in patients with advanced NSCLC. CLINICAL TRIAL INFORMATION: NCT01326767 (https://clinicaltrials.gov/ct2/show/NCT01326767).


Subject(s)
Carboplatin/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Cisplatin/administration & dosage , Paclitaxel/administration & dosage , Adolescent , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Carboplatin/adverse effects , Carboplatin/pharmacokinetics , Carcinoma, Non-Small-Cell Lung/pathology , Cisplatin/adverse effects , Cisplatin/pharmacokinetics , Disease-Free Survival , Dose-Response Relationship, Drug , Drug-Related Side Effects and Adverse Reactions/classification , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Humans , Male , Middle Aged , Neoplasm Staging , Paclitaxel/adverse effects , Paclitaxel/pharmacokinetics
11.
Mater Sci Eng C Mater Biol Appl ; 67: 267-275, 2016 Oct 01.
Article in English | MEDLINE | ID: mdl-27287122

ABSTRACT

Successful bone regeneration following oral and maxillofacial surgeries depends on efficient functionalization strategies that allow the recruitment of osteogenic progenitor cells at the tissue/implant interface. We have previously identified aptamer 74, which exhibited a binding affinity for osteogenically induced jaw periosteal cells (JPCs). In the present study, this aptamer was used for the surface biofunctionalization of ß-tricalcium phosphate (ß-TCP) blocks. Atomic force microscopy (AFM) measurements showed increased binding activity of aptamer 74 towards osteogenically induced JPCs compared to untreated controls. The immobilization efficiency of aptamer 74 was analyzed using the QuantiFluor ssDNA assay for 2D surfaces and by amino acid analysis for 3D ß-TCP constructs. Following the successful immobilization of aptamer 74 in 2D culture wells and on 3D constructs, in vitro assays showed no significant differences in cell proliferation compared to unmodified surfaces. Interestingly, JPC mineralization was significantly higher on the 2D surfaces and higher cell adhesion was detected on the 3D constructs with immobilized aptamer. Herein, we report an established, biocompatible ß-TCP matrix with surface immobilization of aptamer 74, which enhances properties such as cell adhesion on 3D constructs and mineralization on 2D surfaces. Further studies need to be performed to improve the immobilization efficiency and to develop a suitable approach for JPC mineralization growing within 3D ß-TCP constructs.


Subject(s)
Aptamers, Nucleotide/pharmacology , Bone and Bones/physiology , Calcium Phosphates/pharmacology , Tissue Engineering/methods , Bone and Bones/drug effects , Calcification, Physiologic/drug effects , Cell Adhesion/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Humans , Lactic Acid/chemistry , Microscopy, Atomic Force , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Surface Properties
13.
Antimicrob Agents Chemother ; 60(1): 387-92, 2016 01.
Article in English | MEDLINE | ID: mdl-26525787

ABSTRACT

We employed an endpoint genotyping method to update the prevalence rate of positivity for the TR34/L98H mutation (a 34-bp tandem repeat mutation in the promoter region of the cyp51A gene in combination with a substitution at codon L98) and the TR46/Y121F/T289A mutation (a 46-bp tandem repeat mutation in the promoter region of the cyp51A gene in combination with substitutions at codons Y121 and T289) among clinical Aspergillus fumigatus isolates obtained from different regions of Iran over a recent 5-year period (2010 to 2014). The antifungal activities of itraconazole, voriconazole, and posaconazole against 172 clinical A. fumigatus isolates were investigated using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. For the isolates with an azole resistance phenotype, the cyp51A gene and its promoter were amplified and sequenced. In addition, using a LightCycler 480 real-time PCR system, a novel endpoint genotyping analysis method targeting single-nucleotide polymorphisms was evaluated to detect the L98H and Y121F mutations in the cyp51A gene of all isolates. Of the 172 A. fumigatus isolates tested, the MIC values of itraconazole (≥16 mg/liter) and voriconazole (>4 mg/liter) were high for 6 (3.5%). Quantitative analysis of single-nucleotide polymorphisms showed the TR34/L98H mutation in the cyp51A genes of six isolates. No isolates harboring the TR46/Y121F/T289A mutation were detected. DNA sequencing of the cyp51A gene confirmed the results of the novel endpoint genotyping method. By microsatellite typing, all of the azole-resistant isolates had genotypes different from those previously recovered from Iran and from the Dutch TR34/L98H controls. In conclusion, there was not a significant increase in the prevalence of azole-resistant A. fumigatus isolates harboring the TR34/L98H resistance mechanism among isolates recovered over a recent 5-year period (2010 to 2014) in Iran. A quantitative assay detecting a single-nucleotide polymorphism in the cyp51A gene of A. fumigatus is a reliable tool for the rapid screening and monitoring of TR34/L98H- and TR46/Y121F/T289A-positive isolates and can easily be incorporated into clinical mycology algorithms.


Subject(s)
Antifungal Agents/therapeutic use , Aspergillus fumigatus/genetics , Cytochrome P-450 Enzyme System/genetics , Drug Resistance, Fungal/genetics , Fungal Proteins/genetics , Polymorphism, Single Nucleotide , Aspergillosis/drug therapy , Aspergillosis/epidemiology , Aspergillosis/microbiology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/enzymology , Aspergillus fumigatus/isolation & purification , Cytochrome P-450 Enzyme System/metabolism , DNA, Fungal/genetics , Fungal Proteins/metabolism , Gene Expression , Humans , Iran/epidemiology , Itraconazole/therapeutic use , Microbial Sensitivity Tests , Microsatellite Repeats , Mycological Typing Techniques , Promoter Regions, Genetic , Retrospective Studies , Sequence Analysis, DNA , Triazoles/therapeutic use , Voriconazole/therapeutic use
14.
Biomed Mater ; 10(4): 045018, 2015 Aug 04.
Article in English | MEDLINE | ID: mdl-26238604

ABSTRACT

Bone regeneration in critical size defects is a major challenge in oral and maxillofacial surgery, and the gold standard for bone reconstruction still requires the use of autologous tissue. To overcome the need for a second intervention and to minimize morbidity, the development of new biomaterials with osteoinductive features is the focus of current research. As a scaffolding material, ß-tricalcium phosphate (ß-TCP) is suitable for bone regeneration purposes, although it does not carry any functional groups for the covalent immobilization of molecules. The aim of the present study was to establish effective coating variants for ß-TCP constructs to enable the biofunctionalization of anorganic blocks with different osteogenic molecules in future studies. We established working protocols for thin surface coatings consisting of polylactic-co-glycolic acid (PLGA) and graphene oxide (GO) by varying parameters. Surface properties such as the angularity and topography of the developed scaffolds were analyzed. To examine biological functionality, the adhesion and proliferation behavior of jaw periosteal cells (JPCs) were tested on the coated constructs. Our results suggest that PLGA is the superior material for surface coating of ß-TCP matrices, leading to higher JPC proliferation rates and providing a more suitable basis for further biofunctionalization in the field of bone tissue engineering.


Subject(s)
Calcium Phosphates/chemistry , Graphite/chemistry , Lactic Acid/chemistry , Osteoblasts/cytology , Periosteum/cytology , Polyglycolic Acid/chemistry , Tissue Scaffolds , Bone Substitutes/chemical synthesis , Cell Differentiation/physiology , Cells, Cultured , Coated Materials, Biocompatible/chemical synthesis , Equipment Design , Equipment Failure Analysis , Humans , Jaw/cytology , Jaw/physiology , Materials Testing , Osteoblasts/physiology , Periosteum/physiology , Polylactic Acid-Polyglycolic Acid Copolymer
15.
J Clin Microbiol ; 53(7): 2343-5, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25903576

ABSTRACT

High-level pan-azole-resistant Aspergillus fumigatus was recovered from four patients with chronic lung disease. In one patient, the development of progressive resistance followed long-term azole therapy and switching between antifungal azoles. The high-level pan-azole-resistant phenotypes were not associated with a specific cyp51A gene mutation. New strategies that avoid the development of progressive azole resistance are needed.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/isolation & purification , Azoles/pharmacology , Pulmonary Aspergillosis/microbiology , Adult , Aged , Cytochrome P-450 Enzyme System/genetics , Female , Fungal Proteins/genetics , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Mutation , Young Adult
16.
J Antimicrob Chemother ; 70(1): 178-81, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25301884

ABSTRACT

OBJECTIVES: To determine the MIC distributions of itraconazole, voriconazole and posaconazole and non-azole drugs for wild-type cyp51A, as well as TR(34)/L98H and TR(46)/Y121F/T289A cyp51A mutants of Aspergillus fumigatus. METHODS: We retrieved MIC and cyp51A sequence data for 952 clinical A. fumigatus strains isolated in or referred to our reference laboratory, during the January 2010 to December 2013 period. All MICs were determined using the EUCAST methodology and interpreted using the EUCAST breakpoints. RESULTS: Three-hundred and sixty-four of the 952 strains (38%) were resistant to azoles. Of these, 225 contained the TR34/L98H mutation, 98 contained the TR(46)/Y121F/T289A mutation and 39 had no cyp51A mutations. Two isolates harboured other cyp51A mutations, of which one (P216L) has been shown to confer azole resistance. Of the TR(34)/L98H isolates, 99.6% (224/225) were resistant to itraconazole (MICs >2 mg/L), 92.4% (208/225) were resistant to voriconazole (MICs >2 mg/L) and 97.8% (220/225) were resistant to posaconazole (MICs >0.25 mg/L). All TR(46)/Y121F/T289A isolates were resistant to voriconazole (MICs >16 mg/L), 82.7% (81/98) were resistant to itraconazole with a bimodal MIC distribution and 94.9% (93/98) were resistant to posaconazole. The MICs of amphotericin B, anidulafungin and terbinafine were not affected by the presence of azole-resistance mechanisms. CONCLUSIONS: The TR(34)/L98H and TR(46)/Y121F/T289A cyp51A genotypes of A. fumigatus show distinct resistance phenotypes. The mechanisms behind low-level itraconazole resistance in TR(46)/Y121F/T289A isolates warrant future research. The potential of increased azole dosing for disease caused by low-level resistant strains should be investigated.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Azoles/pharmacology , Drug Resistance, Fungal , Echinocandins/pharmacology , Polyenes/pharmacology , Aspergillosis/microbiology , Aspergillus fumigatus/genetics , Aspergillus fumigatus/isolation & purification , Humans , Microbial Sensitivity Tests , Mutation, Missense , Netherlands , Sterol 14-Demethylase/genetics
17.
PLoS One ; 7(3): e31801, 2012.
Article in English | MEDLINE | ID: mdl-22396740

ABSTRACT

BACKGROUND: Azoles play an important role in the management of Aspergillus diseases. Azole resistance is an emerging global problem in Aspergillus fumigatus, and may develop through patient therapy. In addition, an environmental route of resistance development has been suggested through exposure to 14α-demethylase inhibitors (DMIs). The main resistance mechanism associated with this putative fungicide-driven route is a combination of alterations in the Cyp51A-gene (TR(34)/L98H). We investigated if TR(34)/L98H could have developed through exposure to DMIs. METHODS AND FINDINGS: Thirty-one compounds that have been authorized for use as fungicides, herbicides, herbicide safeners and plant growth regulators in The Netherlands between 1970 and 2005, were investigated for cross-resistance to medical triazoles. Furthermore, CYP51-protein homology modeling and molecule alignment studies were performed to identify similarity in molecule structure and docking modes. Five triazole DMIs, propiconazole, bromuconazole, tebuconazole, epoxiconazole and difenoconazole, showed very similar molecule structures to the medical triazoles and adopted similar poses while docking the protein. These DMIs also showed the greatest cross-resistance and, importantly, were authorized for use between 1990 and 1996, directly preceding the recovery of the first clinical TR(34)/L98H isolate in 1998. Through microsatellite genotyping of TR(34)/L98H isolates we were able to calculate that the first isolate would have arisen in 1997, confirming the results of the abovementioned experiments. Finally, we performed induction experiments to investigate if TR(34)/L98H could be induced under laboratory conditions. One isolate evolved from two copies of the tandem repeat to three, indicating that fungicide pressure can indeed result in these genomic changes. CONCLUSIONS: Our findings support a fungicide-driven route of TR(34)/L98H development in A. fumigatus. Similar molecule structure characteristics of five triazole DMIs and the three medical triazoles appear the underlying mechanism of cross resistance development. Our findings have major implications for the assessment of health risks associated with the use of triazole DMIs.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/metabolism , Triazoles/chemistry , Chemistry, Pharmaceutical/methods , Cytochrome P-450 Enzyme System/biosynthesis , Dioxolanes/pharmacology , Drug Resistance, Fungal , Epoxy Compounds/pharmacology , Fungal Proteins/biosynthesis , Fungicides, Industrial/pharmacology , Furans/pharmacology , Genotype , Microsatellite Repeats/genetics , Models, Chemical , Molecular Conformation , Risk , Triazoles/pharmacology
18.
Med Mycol ; 49(8): 848-55, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21619440

ABSTRACT

The performance of the new Platelia Candida Antigen Plus (Ag Plus) and Antibody Plus (Ab Plus) assays (Biorad Laboratories, France) was evaluated using a collection of serum samples obtained from 21 patients with microbiologically proven invasive candidiasis and 30 control patients who were being treated with myeloablative chemotherapy, and the data compared with that obtained with the earlier version of the Platelia Candida assays (Ag and Ab), and 1,3-ß-D-glucan (BG) detection systems. The sensitivity of the Ag Plus and Ab Plus assays in the per patient analysis ranged from 55-70% and from 30-64% for patients with less than 15 days of neutropenia and more than 15 days of neutropenia, respectively. Sensitivity and time to detection of these new assays was not significantly better than of the conventional Platelia Candida tests. However, the specificity of the Ag-Plus assay was reduced by approximately 50% as compared to the Ag assay. Logistic regression analysis showed that this was probably due to the fact that circulating mannan was also being detected by the Ag Plus assay in patients with superficial candidiasis. Further studies are needed to confirm our results and to determine the place of the Platelia Ag Plus and Ab Plus assays in the management of haematology patients at risk for Candida infections.


Subject(s)
Antibodies, Fungal/blood , Antigens, Fungal/blood , Candida/immunology , Candidiasis, Invasive/diagnosis , Mannans/blood , Myeloablative Agonists/adverse effects , Candida/isolation & purification , Candidiasis, Invasive/immunology , Clinical Laboratory Techniques , Fungemia , Humans , Neutropenia , Reagent Kits, Diagnostic , Sensitivity and Specificity
19.
Oncogene ; 29(19): 2795-806, 2010 May 13.
Article in English | MEDLINE | ID: mdl-20190799

ABSTRACT

Nuclear factor-kappaB (NF-kappaB) and p53 critically determine cancer development and progression. Defining the cross talk between these transcription factors can expand our knowledge on molecular mechanisms of tumorigenesis. Here, we show that induction of replicational stress activates NF-kappaB p65 and triggers its interaction with p53 in the nucleus. Experiments with knockout cells show that p65 and p53 are both required for enhanced NF-kappaB activity during S-phase checkpoint activation involving ataxia-telangiectasia mutated and checkpoint kinase-1. Accordingly, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) also triggers formation of a transcriptionally active complex containing nuclear p65 and p53 on kappaB response elements. Gene expression analyses revealed that, independent of NF-kappaB activation in the cytosol, TNF-induced NF-kappaB-directed gene expression relies on p53. Hence, p53 is unexpectedly necessary for NF-kappaB-mediated gene expression induced by atypical and classical stimuli. Remarkably, data from gain- and loss-of function approaches argue that anti-apoptotic NF-kappaB p65 activity is constitutively evoked by a p53 hot-spot mutant frequently found in tumors. Our observations suggest explanations for the outstanding question why p53 mutations rather than p53 deletions arise in tumors of various origins.


Subject(s)
Transcription Factor RelA/metabolism , Tumor Suppressor Protein p53/metabolism , Animals , Apoptosis/drug effects , Ataxia Telangiectasia Mutated Proteins , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Checkpoint Kinase 1 , DNA/genetics , DNA/metabolism , DNA Replication , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydroxyurea/pharmacology , Mice , Mutation , Protein Kinases/metabolism , Protein Serine-Threonine Kinases/metabolism , S Phase/drug effects , Signal Transduction/drug effects , Stress, Physiological/genetics , Transcription, Genetic/drug effects , Transcriptional Activation/drug effects , Tumor Necrosis Factor-alpha/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Proteins/metabolism
20.
Diagn Microbiol Infect Dis ; 64(4): 408-15, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19631094

ABSTRACT

Invasive Candida infections are associated with a significant morbidity and mortality. Detection of circulating biomarkers has been shown to precede conventional diagnostic methods, which is important in improving outcome. We investigated the performance of multiple biomarkers using Candida antigen and anti-Candida antibody detection systems of Platelia and Serion and beta-d-glucan detection in serial serum samples from patients, treated for leukemia, with invasive candidiasis. The performance of single assays and combined detection appeared different for patients with 1 or more episodes of neutropenia and is therefore related to the phase of therapy for the underlying leukemia of the patient. These new insights may help to optimize the diagnostic strategies for the diagnosis of invasive candidiasis.


Subject(s)
Candida/isolation & purification , Candidiasis/diagnosis , Immunosuppressive Agents/therapeutic use , Myeloablative Agonists/therapeutic use , Adolescent , Adult , Aged , Antibodies, Fungal/blood , Antigens, Fungal/blood , Biomarkers , Child , Child, Preschool , Female , Humans , Immunosuppressive Agents/adverse effects , Male , Middle Aged , Myeloablative Agonists/adverse effects , Young Adult , beta-Glucans/blood
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