Fungal respiratory infections in cystic fibrosis

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Cystic Fibrosis and moulds: updates from the last meeting of the working group

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Quels outils pour prendre en compte la biodiversité dans la gestion forestière ? Exemple d’un espace protégé, le Parc national des Cévennes

Le Parc national des Cévennes couvre un territoire de caractère rural, habité, même dans la zone de cœur du Parc. Comment concilier dans cet espace une protection intégrée exemplaire avec une évolution naturelle, économique et sociale ? La loi de réforme des Parcs de 2006, souhaite un engagement plus direct des habitants dans la mise en œuvre de la politique des Parcs nationaux. Dans cet article, nous sont présentés les outils qui permettent d’intégrer la biodiversité à la gestion forestière du Parc des Cévennes

Different colonization patterns of Aspergillus terreus in patients with cystic fibrosis

Due to the abnormal viscosity of airway secretions, patients with cystic fibrosis (CF) are athigh risk of fungal colonization of the respiratory tract. Aspergillus fumigatus is by far the most common fungal specie encountered in the CF context, but other species are increasingly reported such as Scedosporium spp. or Geosmithia argillacea, as well as other aspergilli including Aspergillus terreus. In our experience, this saprophytic fungus ranks the third among the filamentous fungi colonizing the respiratory tract of CF patients. Additionally, although relatively uncommon, infections caused by A. terreus present a high mortality rate due to its usually low susceptibility to systemic antifungals. Nevertheless, little is known about the epidemiology of A. terreus colonization/infections. In the present study, nine short tandem repeats of A. terreus were used to genotype 122 clinical isolates recovered from sputum samples from five patients with CF followed-up in two distinct hospitals in France (Angers and Giens hospitals). Sputum samples were collected over a two-month to seven-year period depending on the patients, and for each sample, all the obtained isolates were studied, with a maximum of five per sample. Three colonization patterns were observed. The first colonization pattern consisted of a chronic colonization (defined as the presence of the same genotype in at least two successive samples collected over a minimum period of two months) by a largely dominant genotype associated with two or three other genotypes found occasionally (patient 4) or over a short period (patient 3). The second colonization pattern consisted of a chronic colonization by two distinct genotypes simultaneously detected (patients 1 and 2). For the last patient (patient 5), who was followed during four years, 16 isolates recovered from 6 sputum samples were analyzed, corresponding to 8 genetically distinct genotypes which succeeded to each other. Numerous questions therefore raise from these different colonization patterns, regarding (i) the origin of the contamination of the patients by this relatively uncommon environmental fungus, (ii) the differences between genotypes in their ability to chronically colonize the airways of the CF patients, or (iii) the differences between CF patients in their individual susceptibility to same genotypes

Scedosporium apiospermum Complex: Diagnosis and Species Identification

Fungi belonging to the Scedosporium apiospermum species complex have been known since the early 20th century as etiologic agents of human infections occurring in immunocompetent individuals as well as immunocompromised people. Additionally, these fungi are now recognized as common colonizers of the airways in patients with cystic fibrosis (CF). The prevalence and importance of these opportunistic pathogens have likely been underestimated, due to the absence of specific features on histological examination of biopsy specimens and the rapid and extensive growth of the aspergilli, which are frequently associated with Scedosporium species in respiratory secretions from CF patients or patients with chronic obstructive pulmonary disease. In this article, the literature on diagnostic and/or identification methods has been reviewed. Development of molecular tools brings about novel challenges in the field of diagnosis, and further studies are required to transfer these methods to routine clinical us

Functionnal biodiversity in mango orchards on Reunion. Ecosystemic and landscape effects on epigeous predatory arthropods.

The knowledge of factors implicated in agroecosystem diversity is necessary to better evaluate their role. The study aims to link within-field plant diversity, cultural practices, and landscape context with terrestrial predatory arthropods in mango orchards on Reunion. Twenty-four plots distributed within the mango production area have been studied. Arthropods were sampled with pitfall traps. The land plots were grouped into three groups of agricultural practice intensity. The landscape was mapped within a circle of 400 meters around the orchards, which permitted to distinguish three different landscape contexts. Based on 83181 arthropods collected, 65124 were determined as predators, their communities were mainly composed of ants (Hymenoptera: Formicinae) and spiders (Araneae). The species richness and their equitability were influenced by factors at three different scales: (1) the within-field plant diversity improved evenness of predatory arthropods communities; (2) the moderate farming practices, as organic farming practices, had higher species richness than those obtained with “conventionnal” practices; (3) a landscape context with relevant heterogeneity and fragmentation increased the species richness of epigeal predatory arthropods in mango orchards

Distribution of the different species of the Pseudallescheria boydii/Scedosporium apiospermum complex in French patients with cystic fibrosis

As various new sibling species within the Pseudallescheria boydii/Scedosporium apiospermum complex have been described recently with differences in their susceptibility to antifungals, this study was conducted in order to determine their respective frequency in cystic fibrosis. Results indicated that P. boydii largely predominated (62%), followed by S. apiospermum (24%), Scedosporium aurantiacum (10%) and Pseudallescheria minutispora (4%). Scedosporium dehoogii was not recovered in this study. The multiple correspondence factor analysis highlighted geographical discrepancies within species distribution: P. boydii was rarely encountered in Northern France, while S. apiospermum was less represented in the west of the country. Additionally, we demonstrated that all species encountered in the cystic fibrosis context were capable to chronically colonize the respiratory tract of patients. Molecular typing of a large set of environmental and clinical isolates should be conducted to delineate the epidemiology of each sibling species in the complex

Different colonization patterns of Aspergillus terreus in patients with cystic fibrosis

Patients with cystic fibrosis (CF) are at high risk of colonization of the respiratory tract by filamentous fungi, mainly Aspergillus fumigatus, but also other Aspergillus species including A. terreus. In our experience, this last fungus ranks the third among the filamentous fungi colonizing the respiratory tract of CF patients. Additionally, although uncommon, infections caused by A. terreus present a high mortality rate due to its usually low susceptibility to systemic antifungals. The recent development of a microsatellite typing system allowed us to investigate the molecular epidemiology of the airway colonization by this fungus in CF. Nine short tandem repeats of A. terreus were used to genotype multiple and sequential isolates from sputum samples from CF patients followed-up in Angers and Giens hospitals (France). Sputum samples were collected over a 2 month to 7 year period, and for each sample, all the obtained isolates were studied, with a maximum of five per sample. Thus a total of 122 isolates was studied, corresponding to 47 samples collected from 5 distinct patients. Three colonization patterns were observed. The first one consisted of a chronic colonization (presence of the same genotype in at least two successive samples collected over a minimum period of two months) by a largely dominant genotype associated with two or three other genotypes found occasionally (patient 1) or over a short period (patient 2). The second pattern consisted of a chronic colonization by two distinct genotypes simultaneously detected (patients 3 and 4). For the last patient (patient 5), 16 isolates recovered from 6 sputum samples collected during four years were analyzed, corresponding to 8 distinct genotypes which succeeded to each other. Numerous questions rise from these different colonization patterns, relatively uncommon environmental fungus; and (ii) differences between genotypes in their ability to chronically colonize the airways of the CF patients or differences between CF patients in their individual susceptibility to same genotypes. Strikingly, some genotypes shared by some patients were responsible for a chronic colonization in some patients while they rapidly disappear in other patients. A multicenter study should be conducted combining genetic study of the host and genotyping of fungal isolates, searching for predisposing factors to the airway colonization by A. terreus

Epidemiology of airway colonization by Scedosporium apiospermum during cystic fibrosis

With a frequency of about 10%, species of the Scedosporium apiospermum complex (which comprises at least five distinct species with different antifungal susceptibility patterns) rank the second among the filamentous fungi colonizing the airways in cystic fibrosis (CF). Additionally, it is clearly established that these fungi may disseminate in case of immunodeficiency and that a chronic colonization of the airways by these pathogens may hinder the success of lung transplantation. In this study, we develop a new genotyping method to investigate the epidemiology of the airway colonization by these fungi. 63 multiple and sequential isolates of S. apiospermum collected from 9 CF patients, and selected among those previously studied by random amplification of polymorphic DNA (RAPD), were analyzed using the automated typing system DiversiLab (bioMérieux) based on PCR amplification of repetitive sequences. The DiversiLab Aspergillus rep-PCR kit which uses specific primers designed for Aspergillus fumigatus, was compared with the pan-fungus DiversiLab Fungal kit. Amplification products were separated by capillary electrophoresis on Agilent B2100 bioanalyzer, leading to single profiles for each isolate which were then compared using the DiversiLab software. In addition, species identification of these isolates was clarified by sequencing the betatubulin gene. Results obtained with both kits were comparable. Nevertheless, differentiation was easier using the DiversiLab Fungal kit. Additionally, rep-PCR usually confirmed the colonization patterns described by RAPD. Only two patients showed distinct genotypes. For Patient 2, two isolates were analyzed which were undistinguishable by RAPD, but rep-PCR revealed that they belonged to distinct genotypes, suggesting a transient colonization. For Patient 8 which showed by RAPD two distinct genotypes, 5 genotypes were found by rep-PCR with a dominant one represented by 5 isolates and two very close genotypes (corresponding to 3 isolates), while 4 other isolates belonged to two distant genotypes. In conclusion, the automated typing system DiversiLab proved to be an easy and efficient method to investigate the molecular epidemiology of the airway colonization by S. apiospermum in CF. Our results also confirm the capacity of the different species from the S. apiospermum complex to chronically colonize the airways of CF patients

Scedosporium apiospermum complex Catalase A1 and Cu-Zn SOD recombinant proteins are useful tools for serodiagnosis of Scedosporium infection

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