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Browsing by Author "Dias, Marta Sofia Forte"

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  • Occupational exposure to fungi in waste sorting from Canada
    Publication . Dias, Marta Sofia Forte; Viegas, Carla
    ABSTRACT - Globally, a significant number of people deal with waste management, and microorganism contamination is seen as an occupational health issue for those who treat solid waste. Waste-related microbiological exposures may occur indoors where waste is processed, or outdoors during its processing and may be caused by the sorting, transfer or cleaning process. The aim of the study is to assess forklift drivers’ exposure by inhalation to fungi, during waste management. A total of 41 samples was used, 16 Cabin Ventilation Filters (ventilation filters from vehicle cabinets of waste management trucks) and 25 filters from air microbiological sampler Surface Air System Super (SASS). The SASS Filters and the Cabin Ventilation Filters extracts were analyzed by culture-based methods (including azole-resistance screening) and qPCR, targeting four Aspergillus sections (Fumigati, Flavi, Nidulantes, and Circumdati). To improve the selectivity for fungal growth, two different culture media were used: malt extract agar (MEA) supplemented with chloramphenicol (0.05%) and dichloran-glycerol agar (DG18). For antifungal resistance screening, samples were spread (0.15 ml) onto Sabouraud dextrose agar media supplemented with 4 mg 𝐿−1 itraconazole (ITR), 1 mg 𝐿−1 voriconazole (VOR), or 0.5 mg 𝐿−1 posaconazole (POS) (protocol adapted from the EUCAST 2017 guidelines). Aspergillus sp. presented the highest prevalence in Cabin Ventilation Filters on MEA (35.8%), while in DG18, the highest prevalence belongs to Penicillium genera (66.5%). In SASS Filters, Aspergillus sp. presented the highest prevalence on MEA (67.6%), whereas on DG18, the highest prevalence belongs to Penicillium sp. (31.1%). Thirteen of the 16 cabin ventilation filter samples (81.2%) presented fungal growth on 4 mg/L ITR, 10 out of 16 (62.5%) samples presented two additional fungal species on 1 mg/L VOR, and in 9 out of 16 (56.2%) samples was observed one additional fungal species on 0.5 mg/L POS. Among Aspergillus genus, Aspergillus sections Fumigati, Flavi, and Nidulantes presented the highest prevalence in Cabin ventilation Filters (2 out of 16; 12.5%), whereas in SASS Filters, the highest prevalence belongs to Aspergillus section Fumigati (3 out of 25; 12%). Regarding molecular tools, detected by PCR in the Cabin Ventilation Filters and in SASS Filter samples, all four sections targeted were detected. Overall, it was possible to assess fungal contamination in the matrices assessed and conclude that the use of different sampling methods such as the Cabin Ventilation Filters and the SASS Filters to assess the occupational exposure to fungi in this type of industry allowed to perform a more complete characterization of the fungal contamination. This study also reinforces the need to assess the exposure to fungal contamination in this specific occupational environment.
    2021Master thesis Open access Show more