Antimykotische Therapie der invasiven pulmonalen Infektion durch Scedosporium und Pseudallescheria spp. bei Mukoviszidose

Autre titre : Antimykotische Therapie der pulmonalen Infektion durch Scedosporien bei MukoviszidoseInternational audienc

Combined antifungal therapy is superior to monotherapy in pulmonary scedosporiosis in cystic fibrosis

Cystic fibrosis (CF) is characterised by chronic airway infection with bacteria and fungi. Infections caused by Scedosporium/Lomentospora species can occur and are difficult to treat. Moulds belonging to the genus Scedosporium/Lomentospora are detected most frequently in respiratory samples of patients with CF, next to Aspergillus spp. Our aim was to define pulmonary fungal infections due to Scedosporium/Lomentospora in CF and to study the antimycotic treatment. In this multicentre study (12 centres; duration January 2008 to December 2014) 31 patients with a lung infection caused by moulds of the genus Scedosporium/Lomentospora were included. 36 courses of antifungal treatment were documented. Scedosporium apiospermum sensu stricto accounted for 48.4% of cases. In 20/31 patients a therapeutic response under antimycotics (median duration 3.9 months) was achieved. Triple and double therapy was significantly more effective compared to monotherapy regarding FEV1, radiology, and symptoms. This data suggests that combined treatment is superior to monotherapy in patients with CF

Multilocus Sequence Typing Reveals Extensive Genetic Diversity of the Emerging Fungal Pathogen Scedosporium aurantiacum

Scedosporium spp. are the second most prevalent filamentous fungi after Aspergillus spp. recovered from cystic fibrosis (CF) patients in various regions of the world. Although invasive infection is uncommon prior to lung transplantation, fungal colonization may be a risk factor for invasive disease with attendant high mortality post-transplantation. Abundant in the environment, Scedosporium aurantiacum has emerged as an important fungal pathogen in a range of clinical settings. To investigate the population genetic structure of S. aurantiacum, a MultiLocus Sequence Typing (MLST) scheme was developed, screening 24 genetic loci for polymorphisms on a tester strain set. The six most polymorphic loci were selected to form the S. aurantiacum MLST scheme: actin (ACT), calmodulin (CAL), elongation factor-1α (EF1α), RNA polymerase subunit II (RPB2), manganese superoxide dismutase (SOD2), and β-tubulin (TUB). Among 188 global clinical, veterinary, and environmental strains, 5 to 18 variable sites per locus were revealed, resulting in 8 to 23 alleles per locus. MLST analysis observed a markedly high genetic diversity, reflected by 159 unique sequence types. Network analysis revealed a separation between Australian and non-Australian strains. Phylogenetic analysis showed two major clusters, indicating correlation with geographic origin. Linkage disequilibrium analysis revealed evidence of recombination. There was no clustering according to the source of the strains: clinical, veterinary, or environmental. The high diversity, especially amongst the Australian strains, suggests that S. aurantiacum may have originated within the Australian continent and was subsequently dispersed to other regions, as shown by the close phylogenetic relationships between some of the Australian sequence types and those found in other parts of the world. The MLST data are accessible at http://mlst.mycologylab.org. This is a joined publication of the ISHAM/ECMM working groups on “Scedosporium/Pseudallescheria Infections” and “Fungal Respiratory Infections in Cystic Fibrosis”.Peer Reviewe

Proposed nomenclature for Pseudallescheria, Scedosporium and related genera

As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi, generic names of many groups should be reconsidered. Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria, Scedosporium and allied taxa. The generic names Parascedosporium, Lomentospora, Petriella, Petriellopsis, and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy, annellidic conidia. Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species, some name changes are proposed. Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S. desertorum, respectively. Scedosporium prolificans is renamed as Lomentospora prolificans

Phospholipid molecular species distributions of Candida isolates from the UK and Iran.

AIMS: Some species of Candida have been shown to differ with respect to their polar lipid fingerprints when analysed by fast atom bombardment mass spectrometry (FABMS). The aims of this study were to contribute to the existing body of information by (i) examining representatives of species not previously examined and (ii) seeking strains differences associated with country of origin (UK or Iran). METHODS AND RESULTS: FABMS analysis was performed on extracted lipids of 22 strains representing eight species of Candida. The most abundant anion (19 isolates) in spectra was with mass to charge (m/z) 281, corresponding to C18:1 carboxylate. The major phospholipid analogue anions were m/z 515 and 501 (13 strains). These anions were putatively identified as the phosphatidyl molecular species PA(23 : 2) and PA(22 : 2) respectively. Data for strain pairs were compared using the Pearson's coefficient of linear correlation. The values generated were used to cluster strains by nearest-neighbour linkage, using both carboxylate and phospholipid analogue anion data. Isolates of C. parapsilosis were clearly distinct from other isolates. Iranian isolates tended to cluster together when phospholipid anion data were used. However, if carboxylate anion data were used, four Iranian isolates of C. albicans were tightly clustered with three UK isolates, of which two were C. albicans and one was C. dubliniensis. CONCLUSION: It is concluded that both lower, and higher, mass peaks in FABMS spectra can be of potential value in comparing Candida isolates from different countries and from different species. SIGNIFICANCE AND IMPACT OF THE STUDY: When polar lipids of different Candida species are compared, it is important to bear in mind that geographical differences affect results as has been observed with bacteria in similar studies