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.

scholarly journals Aspergillus fumigatusIn-Host HOG pathway mutation for Cystic Fibrosis Lung Microenvironment Persistence

2021 ◽  
Author(s):  
Brandon S. Ross ◽  
Lotus A. Lofgren ◽  
Alix Ashare ◽  
Jason E. Stajich ◽  
Robert A. Cramer
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Antifungal Therapy ◽  
Clinical Management ◽  
Atmospheric Oxygen ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Clinical Manifestations ◽  
Low Oxygen ◽  
Hog Pathway ◽  
Unique Allele

AbstractThe prevalence ofAspergillus fumigatuscolonization in individuals with Cystic Fibrosis (CF) and subsequent fungal persistence in the lung is increasingly recognized. However, there is no consensus for clinical management ofA. fumigatusin CF individuals, due largely to uncertainty surroundingA. fumigatusCF pathogenesis and virulence mechanisms. To address this gap in knowledge, a longitudinal series ofA. fumigatusisolates from an individual with CF were collected over 4.5 years. Isolate genotypes were defined with whole genome sequencing that revealed both transitory and persistentA. fumigatusin the lung. Persistent lineage isolates grew most readily in a low oxygen culture environment and conidia were more sensitive to oxidative stress inducing conditions compared to non-persistent isolates. Closely related persistent isolates harbor a unique allele of the high osmolarity glycerol (HOG) pathway mitogen activated protein kinase kinase, Pbs2 (pbs2C2). Data suggest this novelpbs2C2allele arosein vivoand is necessary for the fungal response to osmotic stress in a low oxygen environment through hyperactivation of the HOG (SakA) signaling pathway. Hyperactivation of the HOG pathway throughpbs2C2comes at the cost of decreased conidia stress resistance in the presence of atmospheric oxygen levels. These novel findings shed light on pathoadaptive mechanisms ofA. fumigatusin CF, lay the foundation for identifying persistentA. fumigatusisolates that may require antifungal therapy, and highlight considerations for successful culture of persistent fungal CF isolates.ImportanceAspergillus fumigatusinfection 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 forA. fumigatusairway persistence in CF disease progression. There currently is little consensus for clinical management ofA. fumigatuslong-term culture positivity in CF. A better understanding ofA. fumigatuspathogenesis mechanisms in CF is expected to yield insights into when antifungal therapies are warranted. Here, a 4.5-year longitudinal collection ofA. fumigatusisolates identified a persistent lineage that harbors a unique allele of the Pbs2 MAPKK necessary for unique CF-relevant stress phenotypes. Importantly forA. fumigatusCF patient diagnostics, this allele provides increased CF lung fitness at a cost of reducedin vitrogrowth in standard laboratory conditions. These data illustrate a molecular mechanism forA. fumigatusCF lung persistence with implications for diagnostics and antifungal therapy.

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 New Commercially Available IgG Kits and Time-Resolved Fluorometric IgE Assay for Diagnosis of Allergic Bronchopulmonary Aspergillosis in Patients with Cystic Fibrosis

2015 ◽  
Vol 23 (3) ◽  
pp. 196-203 ◽  
Author(s):  
Coralie Barrera ◽  
Bénédicte Richaud-Thiriez ◽  
Steffi Rocchi ◽  
Bénédicte Rognon ◽  
Sandrine Roussel ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Specific Ige ◽  
Enzyme Linked Immunosorbent Assay ◽  
Time Resolved ◽  
Content Type ◽  
Elisa Kit ◽  
Fungal Allergens ◽  
Specific Igg

ABSTRACTAllergic bronchopulmonary aspergillosis (ABPA) is difficult to diagnose; diagnosis relies on clinical, radiological, pathological, and serological criteria. Our aim was to assess the performance of two new commercially available kits and a new in-house assay: anAspergillus fumigatusenzyme-linked immunosorbent assay (ELISA) IgG kit (Bordier Affinity Products), anAspergillusWestern blotting IgG kit (LDBio Diagnostics), and a new in-house time-resolved fluorometric IgE assay (dissociation-enhanced lanthanide fluorescent immunoassay, or DELFIA) using recombinant proteins from anAspergillussp. recently developed by our laboratory for ABPA diagnosis in a retrospective study that included 26 cystic fibrosis patients.Aspergillus fumigatus-specific IgG levels measured by a commercial ELISA kit were in accordance with the level of precipitins currently used in our lab. The ELISA kit could accelerate and help standardize ABPA diagnosis.Aspergillus fumigatus-specific IgE levels measured by ImmunoCAP (Phadia) withA. fumigatusM3 antigen and by DELFIA with a purified protein extract ofA. fumigatuswere significantly correlated (P< 10−6). The results with recombinant antigens glucose-6-phosphate isomerase and mannitol-1-phosphate dehydrogenase were encouraging but must be confirmed with sera from more patients. The DELFIA is an effective tool that can detect specific IgE against more fungal allergens than can be detected with other commercially available tests.

scholarly journals Eosinophil Deficiency Compromises Lung Defense against Aspergillus fumigatus

2013 ◽  
Vol 82 (3) ◽  
pp. 1315-1325 ◽  
Author(s):  
Lauren M. Lilly ◽  
Michaella Scopel ◽  
Michael P. Nelson ◽  
Ashley R. Burg ◽  
Chad W. Dunaway ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Cell Contact ◽  
Mrna Levels ◽  
Colony Stimulating Factor ◽  
Content Type ◽  
Eosinophil Peroxidase ◽  
Stimulating Factor ◽  
Deficient Mice

ABSTRACTExposure to the moldAspergillus fumigatusmay result in allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, or invasive aspergillosis (IA), depending on the host's immune status. Neutrophil deficiency is the predominant risk factor for the development of IA, the most life-threatening condition associated withA. fumigatusexposure. Here we demonstrate that in addition to neutrophils, eosinophils are an important contributor to the clearance ofA. fumigatusfrom the lung. AcuteA. fumigatuschallenge in normal mice induced the recruitment of CD11b+Siglec F+Ly-6GloLy-6CnegCCR3+eosinophils to the lungs, which was accompanied by an increase in lungEpx(eosinophil peroxidase) mRNA levels. Mice deficient in the transcription factor dblGATA1, which exhibit a selective deficiency in eosinophils, demonstrated impairedA. fumigatusclearance and evidence of germinating organisms in the lung. Higher burden correlated with lower mRNA expression ofEpx(eosinophil peroxidase) andPrg2(major basic protein) as well as lower interleukin 1β (IL-1β), IL-6, IL-17A, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and CXCL1 levels. However, examination of lung inflammatory cell populations failed to demonstrate defects in monocyte/macrophage, dendritic cell, or neutrophil recruitment in dblGATA1-deficient mice, suggesting that the absence of eosinophils in dlbGATA1-deficient mice was the sole cause of impaired lung clearance. We show that eosinophils generated from bone marrow have potent killing activity againstA. fumigtausin vitro, which does not require cell contact and can be recapitulated by eosinophil whole-cell lysates. Collectively, our data support a role for eosinophils in the lung response afterA. fumigatusexposure.

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 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 Iron-Mediated Control of Pseudomonas aeruginosa-Staphylococcus aureus Interactions in the Cystic Fibrosis Lung

2015 ◽  
Vol 197 (14) ◽  
pp. 2250-2251 ◽  
Author(s):  
Patricia M. Barnabie ◽  
Marvin Whiteley
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Patient Outcomes ◽  
Cystic Fibrosis Lung ◽  
Bacterial Survival ◽  
Content Type ◽  
Host Environment ◽  
Bacterial Interactions

Communication is an important factor for bacterial survival, growth, and persistence. Much work has examined both inter- and intraspecies interactions and their effects on virulence. Now, researchers have begun to explore the ways in which host-modulated factors can impact bacterial interactions and subsequently affect patient outcomes. In this issue, two papers discuss how the host environment alters interactions between the pathogensPseudomonas aeruginosaandStaphylococcus aureus, largely in the context of cystic fibrosis.

scholarly journals Aspergillus fumigatus Cell Wall Promotes Apical Airway Epithelial Recruitment of Human Neutrophils

2019 ◽  
Vol 88 (2) ◽  
Author(s):  
Michael B. Feldman ◽  
Richard A. Dutko ◽  
Michael A. Wood ◽  
Rebecca A. Ward ◽  
Hui Min Leung ◽  
...  
Keyword(s):  
Cell Wall ◽  
Aspergillus Fumigatus ◽  
Airway Epithelium ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Human Neutrophils ◽  
Fungal Colonization ◽  
Small Airways ◽  
Content Type ◽  
Human Airway ◽  
Human Airway Epithelium

ABSTRACT Aspergillus fumigatus is a ubiquitous fungal pathogen capable of causing multiple pulmonary diseases, including invasive aspergillosis, chronic necrotizing aspergillosis, fungal colonization, and allergic bronchopulmonary aspergillosis. Intact mucociliary barrier function and early airway neutrophil responses are critical for clearing fungal conidia from the host airways prior to establishing disease. Following inhalation, Aspergillus conidia deposit in the small airways, where they are likely to make their initial host encounter with epithelial cells. Challenges in airway infection models have limited the ability to explore early steps in the interactions between A. fumigatus and the human airway epithelium. Here, we use inverted air-liquid interface cultures to demonstrate that the human airway epithelium responds to apical stimulation by A. fumigatus to promote the transepithelial migration of neutrophils from the basolateral membrane surface to the apical airway surface. Promoting epithelial transmigration with Aspergillus required prolonged exposure with live resting conidia. Swollen conidia did not expedite epithelial transmigration. Using A. fumigatus strains containing deletions of genes for cell wall components, we identified that deletion of the hydrophobic rodlet layer or dihydroxynaphthalene-melanin in the conidial cell wall amplified the epithelial transmigration of neutrophils, using primary human airway epithelium. Ultimately, we show that an as-yet-unidentified nonsecreted cell wall protein is required to promote the early epithelial transmigration of human neutrophils into the airspace in response to A. fumigatus. Together, these data provide critical insight into the initial epithelial host response to Aspergillus.

scholarly journals Coinfection with Pseudomonas aeruginosa and Aspergillus fumigatus in cystic fibrosis

2020 ◽  
Vol 29 (158) ◽  
pp. 200011
Author(s):  
Karen Keown ◽  
Alastair Reid ◽  
John E. Moore ◽  
Clifford C. Taggart ◽  
Damian G. Downey
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus ◽  
Lung Disease ◽  
Disease Progression ◽  
Expert Knowledge ◽  
Fungal Species ◽  
Interspecies Interactions ◽  
Cross Sectional ◽  
Infection And Inflammation

ObjectivesCystic fibrosis (CF) lung disease is characterised by mucus stasis, chronic infection and inflammation, causing progressive structural lung disease and eventual respiratory failure. CF airways are inhabited by an ecologically diverse polymicrobial environment with vast potential for interspecies interactions, which may be a contributing factor to disease progression. Pseudomonas aeruginosa and Aspergillus fumigatus are the most common bacterial and fungal species present in CF airways respectively and coinfection results in a worse disease phenotype.MethodsIn this review we examine existing expert knowledge of chronic co-infection with P. aeruginosa and A. fumigatus in CF patients. We summarise the mechanisms of interaction and evaluate the clinical and inflammatory impacts of this co-infection.ResultsP. aeruginosa inhibits A. fumigatus through multiple mechanisms: phenazine secretion, iron competition, quorum sensing and through diffusible small molecules. A. fumigatus reciprocates inhibition through gliotoxin release and phenotypic adaptations enabling evasion of P. aeruginosa inhibition. Volatile organic compounds secreted by P. aeruginosa stimulate A. fumigatus growth, while A. fumigatus stimulates P. aeruginosa production of cytotoxic elastase.ConclusionA complex bi-directional relationship exists between P. aeruginosa and A. fumigatus, exhibiting both mutually antagonistic and cooperative facets. Cross-sectional data indicate a worsened disease state in coinfected patients; however, robust longitudinal studies are required to derive causality and to determine whether interspecies interaction contributes to disease progression.

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