scholarly journals Detection of Airway Colonization by Aspergillus fumigatus by Use of Electronic Nose Technology in Patients with Cystic Fibrosis

2015 ◽  
Vol 54 (3) ◽  
pp. 569-575 ◽  
Author(s):  
K. de Heer ◽  
M. G. M. Kok ◽  
N. Fens ◽  
E. J. M. Weersink ◽  
A. H. Zwinderman ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Electronic Nose ◽  
External Validation ◽  
Invasive Pulmonary Aspergillosis ◽  
Principal Component ◽  
Exhaled Breath ◽  
Roc Curve Analysis ◽  
Noninvasive Test ◽  
Content Type

Currently, there is no noninvasive test that can reliably diagnose early invasive pulmonary aspergillosis (IA). An electronic nose (eNose) can discriminate various lung diseases through an analysis of exhaled volatile organic compounds. We recently published a proof-of-principle study showing that patients with prolonged chemotherapy-induced neutropenia and IA have a distinct exhaled breath profile (or breathprint) that can be discriminated with an eNose. An eNose is cheap and noninvasive, and it yields results within minutes. We determined whetherAspergillus fumigatuscolonization may also be detected with an eNose in cystic fibrosis (CF) patients. Exhaled breath samples of 27 CF patients were analyzed with a Cyranose 320. Culture of sputum samples defined theA. fumigatuscolonization status. eNose data were classified using canonical discriminant analysis after principal component reduction. Our primary outcome was cross-validated accuracy, defined as the percentage of correctly classified subjects using the leave-one-out method. ThePvalue was calculated by the generation of 100,000 random alternative classifications. Nine of the 27 subjects were colonized byA. fumigatus. In total, 3 subjects were misclassified, resulting in a cross-validated accuracy of the Cyranose detecting IA of 89% (P= 0.004; sensitivity, 78%; specificity, 94%). Receiver operating characteristic (ROC) curve analysis showed an area under the curve (AUC) of 0.89. The results indicate thatA. fumigatuscolonization leads to a distinctive breathprint in CF patients. The present proof-of-concept data merit external validation and monitoring studies.

scholarly journals Influence of age and gender on the profile of exhaled volatile organic compounds analyzed by an electronic nose

2016 ◽  
Vol 42 (2) ◽  
pp. 143-145 ◽  
Author(s):  
Silvano Dragonieri ◽  
Vitaliano Nicola Quaranta ◽  
Pierluigi Carratu ◽  
Teresa Ranieri ◽  
Onofrio Resta
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Electronic Nose ◽  
Principal Component ◽  
Exhaled Breath ◽  
Age And Gender ◽  
Volatile Organic ◽  
Older Subjects ◽  
Never Smokers ◽  
And Gender

We aimed to investigate the effects of age and gender on the profile of exhaled volatile organic compounds. We evaluated 68 healthy adult never-smokers, comparing them by age and by gender. Exhaled breath samples were analyzed by an electronic nose (e-nose), resulting in "breathprints". Principal component analysis and canonical discriminant analysis showed that older subjects (≥ 50 years of age) could not be distinguished from younger subjects on the basis of their breathprints, as well as that the breathprints of males could not distinguished from those of females (cross-validated accuracy, 60.3% and 57.4%, respectively).Therefore, age and gender do not seem to affect the overall profile of exhaled volatile organic compounds measured by an e-nose.

scholarly journals High Prevalence of Azole-Resistant Aspergillus fumigatus in Adults with Cystic Fibrosis Exposed to Itraconazole

2011 ◽  
Vol 56 (2) ◽  
pp. 869-874 ◽  
Author(s):  
Pierre-Régis Burgel ◽  
Marie-Thérèse Baixench ◽  
Michaël Amsellem ◽  
Etienne Audureau ◽  
Jeanne Chapron ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Previous Treatment ◽  
University Hospital ◽  
Clinical Implications ◽  
Content Type ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Prevalence

ABSTRACTAspergillus fumigatusis the most frequent fungus found in the sputum of cystic fibrosis (CF) subjects. Itraconazole is prescribed for allergic bronchopulmonary aspergillosis (ABPA) orAspergillusbronchitis in CF subjects. We hypothesized thatA. fumigatusisolates in the sputum of CF subjects with previous exposure to itraconazole was associated with higher prevalence of azole resistance. From June 2010 to April 2011, sputum samples from adult CF subjects at Cochin University Hospital (France) were examined systematically for the detection ofA. fumigatus. MICs ofA. fumigatusisolates against azoles were screened using Etest, and reduced susceptibility to azoles was confirmed using the CLSI broth microdilution method.A. fumigatuswas isolated from the sputum of 131/249 (52.6%) adult CF subjects, and 47/131 (35.9%) subjects had received previous treatment with itraconazole. ReducedA. fumigatussusceptibility to itraconazole (MIC, ≥2 mg/liter) was confirmed in 6/131 (4.6%) subjects. All 6 isolates also had reduced susceptibility to posaconazole (MIC, ≥0.5 mg/liter), and 3/6 isolates had reduced susceptibility to voriconazole (MIC, ≥2 mg/liter). Mutations in thecyp51Agene were detected at positions previously implicated to cause resistance in 5 isolates. Azole-resistantA. fumigatusisolates were found in 5/25 (20%) subjects exposed to itraconazole within the previous 3 years. High rates of azole-resistantA. fumigatusisolates were present in adult CF subjects and were associated with recent itraconazole exposure. Although the clinical implications of these findings will require further studies, the cautious use of itraconazole in adult CF subjects can be recommended.

scholarly journals Biotinylated Surfome Profiling Identifies Potential Biomarkers for Diagnosis and Therapy of Aspergillus fumigatus Infection

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Lei-Jie Jia ◽  
Thomas Krüger ◽  
Matthew G. Blango ◽  
Ferdinand von Eggeling ◽  
Olaf Kniemeyer ◽  
...  
Keyword(s):  
Immune Responses ◽  
Aspergillus Fumigatus ◽  
Dynamic Change ◽  
Invasive Pulmonary Aspergillosis ◽  
Direct Interaction ◽  
Surface Proteins ◽  
Host Cells ◽  
Human Immune System ◽  
Data Set ◽  
Content Type

ABSTRACT Aspergillus fumigatus is one of the most common airborne molds capable of causing mycoses and allergies in humans. During infection, fungal surface proteins mediate the first contact with the human immune system to evade immune responses or to induce hypersensitivity. Several methods have been established for surface proteomics (surfomics). Biotinylation coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification of peptides is a particularly efficient method to identify the surface-exposed regions of proteins that potentially mediate interaction with the host. After biotinylation of surface proteins during spore germination, we detected 231 different biotinylated surface proteins (including several well-known proteins such as RodA, CcpA, and DppV; allergens; and heat shock proteins [HSPs]), as well as some previously undescribed surface proteins. The dynamic change of the surface proteome was illustrated by detection of a relatively high number of proteins exclusively at one developmental stage. Using immunofluorescence microscopy, we confirmed the surface localization of several HSPs of the HSP70 family, which may have moonlighting functions. Collectively, by comparing our data with data representative of previously published A. fumigatus surface proteomes, our study generated a comprehensive data set corresponding to the A. fumigatus surfome and uncovered the surface-exposed regions of many proteins on the surface of conidia or hyphae. These surface-exposed regions are candidates for direct interaction with host cells and may represent antigenic epitopes that either induce protective immune responses or mediate immune evasion. Thus, our data sets provided and compiled here represent reasonable immunotherapy and diagnostic targets for future investigations. IMPORTANCE Aspergillus fumigatus is the most important airborne human-pathogenic mold, capable of causing both life-threatening invasive pulmonary aspergillosis in immunocompromised patients and allergy-inducing infections in individuals with atopic allergy. Despite its obvious medical relevance, timely diagnosis and efficient antifungal treatment of A. fumigatus infection remain major challenges. Proteins on the surface of conidia (asexually produced spores) and mycelium directly mediate host-pathogen interaction and also may serve as targets for diagnosis and immunotherapy. However, the similarity of protein sequences between A. fumigatus and other organisms, sometimes even including the human host, makes selection of targets for immunological-based studies difficult. Here, using surface protein biotinylation coupled with LC-MS/MS analysis, we identified hundreds of A. fumigatus surface proteins with exposed regions, further defining putative targets for possible diagnostic and immunotherapeutic design.

scholarly journals Studies of Pseudomonas aeruginosa Mutants Indicate Pyoverdine as the Central Factor in Inhibition of Aspergillus fumigatus Biofilm

2017 ◽  
Vol 200 (1) ◽  
Author(s):  
Gabriele Sass ◽  
Hasan Nazik ◽  
John Penner ◽  
Hemi Shah ◽  
Shajia Rahman Ansari ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus ◽  
Fungal Pathogens ◽  
Human Pathogens ◽  
Biofilm Growth ◽  
Content Type ◽  
Iron Deprivation

ABSTRACT Pseudomonas aeruginosa and Aspergillus fumigatus are common opportunistic bacterial and fungal pathogens, respectively. They often coexist in airways of immunocompromised patients and individuals with cystic fibrosis, where they form biofilms and cause acute and chronic illnesses. Hence, the interactions between them have long been of interest and it is known that P. aeruginosa can inhibit A. fumigatus in vitro. We have approached the definition of the inhibitory P. aeruginosa molecules by studying 24 P. aeruginosa mutants with various virulence genes deleted for the ability to inhibit A. fumigatus biofilms. The ability of P. aeruginosa cells or their extracellular products produced during planktonic or biofilm growth to affect A. fumigatus biofilm metabolism or planktonic A. fumigatus growth was studied in agar and liquid assays using conidia or hyphae. Four mutants, the pvdD pchE, pvdD, lasR rhlR, and lasR mutants, were shown to be defective in various assays. This suggested the P. aeruginosa siderophore pyoverdine as the key inhibitory molecule, although additional quorum sensing-regulated factors likely contribute to the deficiency of the latter two mutants. Studies of pure pyoverdine substantiated these conclusions and included the restoration of inhibition by the pyoverdine deletion mutants. A correlation between the concentration of pyoverdine produced and antifungal activity was also observed in clinical P. aeruginosa isolates derived from lungs of cystic fibrosis patients. The key inhibitory mechanism of pyoverdine was chelation of iron and denial of iron to A. fumigatus. IMPORTANCE Interactions between human pathogens found in the same body locale are of vast interest. These interactions could result in exacerbation or amelioration of diseases. The bacterium Pseudomonas aeruginosa affects the growth of the fungus Aspergillus fumigatus. Both pathogens form biofilms that are resistant to therapeutic drugs and host immunity. P. aeruginosa and A. fumigatus biofilms are found in vivo, e.g., in the lungs of cystic fibrosis patients. Studying 24 P. aeruginosa mutants, we identified pyoverdine as the major anti-A. fumigatus compound produced by P. aeruginosa. Pyoverdine captures iron from the environment, thus depriving A. fumigatus of a nutrient essential for its growth and metabolism. We show how microbes of different kingdoms compete for essential resources. Iron deprivation could be a therapeutic approach to the control of pathogen growth.

scholarly journals Dsc Orthologs Are Required for Hypoxia Adaptation, Triazole Drug Responses, and Fungal Virulence in Aspergillus fumigatus

2012 ◽  
Vol 11 (12) ◽  
pp. 1557-1567 ◽  
Author(s):  
Sven D. Willger ◽  
E. Jean Cornish ◽  
Dawoon Chung ◽  
Brittany A. Fleming ◽  
Margaret M. Lehmann ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Regulatory Element ◽  
Invasive Pulmonary Aspergillosis ◽  
Fungal Growth ◽  
Drug Susceptibility ◽  
Antifungal Drugs ◽  
Fungal Virulence ◽  
Content Type ◽  
Hypoxia Adaptation ◽  
Element Binding Protein

ABSTRACTHypoxia is an environmental stress encountered byAspergillus fumigatusduring invasive pulmonary aspergillosis (IPA). The ability of this mold to adapt to hypoxia is important for fungal virulence and genetically regulated in part by the sterol regulatory element binding protein (SREBP) SrbA. SrbA is required for fungal growth in the murine lung and to ultimately cause lethal disease in murine models of IPA. Here we identified and partially characterized four genes (dscA,dscB,dscC, anddscD, here referred to asdscA-D) with previously unknown functions inA. fumigatusthat are orthologs of theSchizosaccharomyces pombegenesdsc1,dsc2,dsc3, anddsc4(dsc1-4), which encode a Golgi E3 ligase complex critical for SREBP activation by proteolytic cleavage.A. fumigatusnulldscA-Dmutants displayed remarkable defects in hypoxic growth and increased susceptibility to triazole antifungal drugs. Consistent with the confirmed role of these genes inS. pombe, both ΔdscAand ΔdscCresulted in reduced cleavage of the SrbA precursor protein inA. fumigatus. Inoculation of corticosteroid immunosuppressed mice with ΔdscAand ΔdscCstrains revealed that these genes are critical forA. fumigatusvirulence. Reintroduction of SrbA amino acids 1 to 425, encompassing the N terminus DNA binding domain, into the ΔdscAstrain was able to partially restore virulence, further supporting a mechanistic link between DscA and SrbA function. Thus, we have shown for the first time the importance of a previously uncharacterized group of genes inA. fumigatusthat mediate hypoxia adaptation, fungal virulence, and triazole drug susceptibility and that are likely linked to regulation of SrbA function.

scholarly journals The Small GTPase RacA Mediates Intracellular Reactive Oxygen Species Production, Polarized Growth, and Virulence in the Human Fungal Pathogen Aspergillus fumigatus

2010 ◽  
Vol 10 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Haiyan Li ◽  
Bridget M. Barker ◽  
Nora Grahl ◽  
Srisombat Puttikamonkul ◽  
Jeremey D. Bell ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Aspergillus Fumigatus ◽  
Invasive Pulmonary Aspergillosis ◽  
Reactive Oxygen ◽  
Small Gtpase ◽  
Oxygen Species ◽  
Wild Type ◽  
Content Type ◽  
Diphenylene Iodonium

ABSTRACTAspergillus fumigatusis the predominant mold pathogen in immunocompromised patients. In this study, we present the first characterization of the small GTPase RacA inA. fumigatus. To gain insight into the function ofracAin the growth and pathogenesis ofA. fumigatus, we constructed a strain that lacks a functionalracAgene. The ΔracAstrain showed significant morphological defects, including a reduced growth rate and abnormal conidiogenesis on glucose minimal medium. In the ΔracAstrain, apical dominance in the leading hyphae is lost and, instead, multiple axes of polarity emerge. Intriguingly, superoxide production at the hyphal tips was reduced by 25% in the ΔracAstrain. Treatment of wild-type hyphae with diphenylene iodonium, an inhibitor of NADPH oxidase, resulted in phenotypes similar to that of the ΔracAstrain. These data suggest that ΔracAstrain phenotypes may be due to a reduction or alteration in the production of reactive oxygen species. Most surprisingly, despite these developmental and growth abnormalities, the ΔracAstrain retained at least wild-type virulence in both an insect model and two immunologically distinct murine models of invasive pulmonary aspergillosis. These results demonstrate thatin vitrogrowth phenotypes do not always correlate within vivovirulence and raise intriguing questions about the role of RacA inAspergillusvirulence.

scholarly journals Synergistic Interaction of the Triple Combination of Amphotericin B, Ciprofloxacin, and Polymorphonuclear Neutrophils against Aspergillus fumigatus

2011 ◽  
Vol 55 (12) ◽  
pp. 5923-5929 ◽  
Author(s):  
Theodouli Stergiopoulou ◽  
Joseph Meletiadis ◽  
Tin Sein ◽  
Paraskevi Papaioannidou ◽  
Thomas J. Walsh ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Invasive Pulmonary Aspergillosis ◽  
Synergistic Interaction ◽  
Polymorphonuclear Neutrophils ◽  
Dependent Manner ◽  
Triple Combination ◽  
Pharmacodynamic Interaction ◽  
Content Type

ABSTRACTAspergillusis damaged by polymorphonuclear neutrophils (PMNs) by means of nonoxidative and oxidative mechanisms, which may be affected by antifungal and antibacterial agents that patients with invasive pulmonary aspergillosis often receive. The pharmacodynamic interactions among deoxycholate amphotericin B (AMB), ciprofloxacin (CIP), and human PMNs againstAspergillus fumigatusgrowth are unknown. We therefore studied the interactions between 0.032 to 2.0 μg/ml of AMB, 0.1 to 50 μg/ml of CIP at a fixed AMB/CIP ratio of 1:3.125, and PMNs from six donors at an effector-to-target (E:T) ratio of 400:1 against a clinicalA. fumigatusisolate using an XTT metabolic assay and the Bliss independence pharmacodynamic-interaction model. CIP exhibited no antifungal activity alone or in combination with PMNs. Synergy was found between AMB and PMNs, with interaction indices (II) of 0.06 to 0.21; the highest interaction of 21% ± 3.6% was observed at 0.22 ± 0.09 μg/ml of AMB. The AMB and CIP (AMB+CIP) combination was synergistic (II = 0.39) at low AMB concentrations and antagonistic (II = 1.39) at high AMB concentrations, with a maximal synergistic interaction of 16% ± 3.7% observed at 0.16 ± 0.08 μg/ml of AMB. The triple combination AMB+CIP+PMNs was synergistic, with interaction indices of 0.05 to 0.20, and a maximal synergistic interaction of 24% ± 4% was observed at 0.20 ± 0.07 μg/ml of AMB. The increased percentage of Bliss synergy of the triple combination AMB+CIP+PMNs (24% ± 4%) was the product of those of the constituent double combinations AMB+PMNs (21% ± 3.6%) and AMB+CIP (16% ± 3.7%). Thus, the antifungal activity of AMB, at clinically relevant concentrations, was enhanced in combination with PMNs and CIP againstA. fumigatusgrowth in a concentration-dependent manner.

scholarly journals Identification and Characterization of a Novel Aspergillus fumigatus Rhomboid Family Putative Protease, RbdA, Involved in Hypoxia Sensing and Virulence

2016 ◽  
Vol 84 (6) ◽  
pp. 1866-1878 ◽  
Author(s):  
Yakir Vaknin ◽  
Falk Hillmann ◽  
Rossana Iannitti ◽  
Netali Ben Baruch ◽  
Hana Sandovsky-Losica ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Regulatory Element ◽  
Invasive Pulmonary Aspergillosis ◽  
Hyphal Growth ◽  
Fungal Virulence ◽  
Th17 Response ◽  
Content Type ◽  
Genes Encoding ◽  
Element Binding Protein

Aspergillus fumigatusis the most common pathogenic mold infecting humans and a significant cause of morbidity and mortality in immunocompromised patients. In invasive pulmonary aspergillosis,A. fumigatusspores are inhaled into the lungs, undergoing germination and invasive hyphal growth. The fungus occludes and disrupts the blood vessels, leading to hypoxia and eventual tissue necrosis. The ability of this mold to adapt to hypoxia is regulated in part by the sterol regulatory element binding protein (SREBP) SrbA and the DscA to DscD Golgi E3 ligase complex critical for SREBP activation by proteolytic cleavage. Loss of the genes encoding these proteins results in avirulence. To identify novel regulators of hypoxia sensing, we screened theNeurospora crassagene deletion library under hypoxia and identified a novel rhomboid family protease essential for hypoxic growth. Deletion of theA. fumigatusrhomboid homologrbdAresulted in an inability to grow under hypoxia, hypersensitivity to CoCl2, nikkomycin Z, fluconazole, and ferrozine, abnormal swollen tip morphology, and transcriptional dysregulation—accurately phenocopying deletion ofsrbA. In vivo,rbdAdeletion resulted in increased sensitivity to phagocytic killing, a reduced inflammatory Th1 and Th17 response, and strongly attenuated virulence. Phenotypic rescue of the ΔrbdAmutant was achieved by expression and nuclear localization of the N terminus of SrbA, including its HLH domain, further indicating that RbdA and SrbA act in the same signaling pathway. In summary, we have identified RbdA, a novel putative rhomboid family protease inA. fumigatusthat mediates hypoxia adaptation and fungal virulence and that is likely linked to SrbA cleavage and activation.

scholarly journals Aspergillus fumigatus In-Host HOG Pathway Mutation for Cystic Fibrosis Lung Microenvironment Persistence

mBio ◽  
2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Brandon S. Ross ◽  
Lotus A. Lofgren ◽  
Alix Ashare ◽  
Jason E. Stajich ◽  
Robert A. Cramer
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Disease Progression ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Clinical Manifestations ◽  
Cystic Fibrosis Lung ◽  
Hog Pathway ◽  
Content Type

Aspergillus fumigatus infection causes a spectrum of clinical manifestations. For individuals with cystic fibrosis (CF), allergic bronchopulmonary aspergillosis (ABPA) is an established complication, but there is a growing appreciation for A. fumigatus airway persistence in CF disease progression.

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