Assessment of fungal spores and spore-like diversity in environmental samples by targeted lysis.

At particular stages during their life cycles, fungi use multiple strategies to form specialized structures to survive unfavorable environmental conditions. These strategies encompass sporulation, as well as cell-wall melanization, multicellular tissue formation or even dimorphism. The resulting structures are not only used to disperse to other environments, but also to survive long periods of time awaiting favorable growth conditions. As a result, these specialized fungal structures are part of the microbial seed bank, which is known to influence the microbial community composition and contribute to the maintenance of diversity. Despite the importance of the microbial seed bank in the environment, methods to study the diversity of fungal structures with improved resistance only target spores dispersing in the air, omitting the high diversity of these structures in terms of morphology and environmental distribution. In this study, we applied a separation method based on cell lysis to enrich lysis-resistant fungal structures (for instance, spores, sclerotia, melanized yeast) to obtain a proxy of the composition of the fungal seed bank. This approach was first evaluated in-vitro in selected species. The results obtained showed that DNA from fungal spores and from yeast was only obtained after the application of the enrichment method, while mycelium was always lysed. After validation, we compared the diversity of the total and lysis-resistant fractions in the polyextreme environment of the Salar de Huasco, a high-altitude athalassohaline wetland in the Chilean Altiplano. Environmental samples were collected from the salt flat and from microbial mats in small surrounding ponds. Both the lake sediments and microbial mats were dominated by Ascomycota and Basidiomycota, however, the diversity and composition of each environment differed at lower taxonomic ranks. Members of the phylum Chytridiomycota were enriched in the lysis-resistant fraction, while members of the phylum Rozellomycota were never detected in this fraction. Moreover, we show that the community composition of the lysis-resistant fraction reflects the diversity of life cycles and survival strategies developed by fungi in the environment. To the best of our knowledge this is the first time that the fungal diversity is explored in the Salar de Huasco. In addition, the method presented here provides a simple and culture independent approach to assess the diversity of fungal lysis-resistant cells in the environment

A DISPOSABLE OPTICAL BIOSENSOR BASED ON TOTAL INTERNAL REFLECTION FLUORESCENCE

A novel disposable biosensor device is described, based on the generation of evanescent light waves at an optical interface. The sensor is injection moulded from high optical quality plastic and consists of two parts, the waveguide and a cuvette for containing the sample solution. Antigens are attached to the waveguide surface and the reaction with antibodies is monitored by exciting and collecting fluorescent light "back-tunneled" out of the waveguide. A model assay for human IgG is used to demonstrate that this biosensor can give rapid, sensitive results

Cutaneous presentation of enteropathy-associated T-cell lymphoma masquerading as a DUSP22-rearranged CD30+ lymphoproliferation.

DUSP22 gene rearrangements are recurrent in systemic and cutaneous ALK-negative anaplastic large cell lymphomas, rarely encountered in other cutaneous CD30+ lymphoproliferations, and typically absent in other peripheral T-cell lymphomas. We report the case of a 51-year-old woman, with longstanding celiac disease and a rapidly enlarging leg ulcer, due to a DUSP22-rearranged CD30+ T-cell lymphoproliferation. Subsequent history revealed an intestinal enteropathy-associated T-cell lymphoma (EATL). Identical monoclonal TR gene rearrangements and mutations in STAT3 and JAK1 typical of EATL were present in the cutaneous and intestinal lesions. No DUSP22 rearrangement was detected in the patient's intestinal tumour, nor in 15 additional EATLs tested. These findings indicate that DUSP22 rearrangements are not entirely specific of ALCLs, may rarely occur as a secondary aberration in EATL, and expand the differential diagnosis of DUSP22-rearranged cutaneous CD30+ lymphoproliferative disorders