Percorrer por autor "Mateus, Margarida"
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- Azole-resistant molds in environmental samples from Portuguese dwellingsPublication . Viegas, Carla; Sá, Flávio; Mateus, Margarida; Santos, Patrícia; Faria, Tiago; Zegre, Miguel; Caetano, Liliana AranhaThe indoor environment is a source of bioburden associated with serious health effects. The emergence of fungal resistance to antifungals is a problem in the management of fungal diseases, being a major concern for Candida sp., Aspergillus sp., and Mucorales order. This study determines the prevalence of azole-resistant bioburden in Portuguese dwellings through passive sampling methods and screening in azole supplemented media.
- Bioburden characterization in Portuguese dwellingsPublication . Viegas, Carla; Sá, Flávio; Mateus, Margarida; Santos, Patrícia; Monteiro, Ana; Faria, Tiago; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Vicente, Estela; Alves, CéliaSeveral studies have indicated that bioburden presence in the indoor environment is associated with serious health effects. Passive sampling methods are easy to use and represent a long-term integrated sample. This study intended to characterize bioburden and assess the azole-resistant fungi through electrostatic dust cloth from 23 dwellings from Aveiro.
- Bioburden characterization in Portuguese dwellingsPublication . Sá, Flávio; Mateus, Margarida; Santos, Patrícia; Monteiro, Ana; Faria, Tiago; Viegas, CarlaO microbiota presente em ambientes interiores está associado a riscos para a saúde dos ocupantes, como asma, alergias e desconforto respiratório, aumentando a importância da sua caracterização nestes ambientes. Realizou-se um estudo com o objetivo de caracterizar o microbiota de 23 casas situadas na região de Aveiro. Como método de amostragem passivo, foram usados precipitadores electrostáticos. A concentração fúngica variou entre 448 e 74742 CFU/m2e a bacteriana variou entre 249 e 31548 CFU/m2. O Quarto foi o local amostrado que apresentou maior contaminação. O método de amostragem passiva utilizada deverá ser considerado em estudos futuros para avaliar o risco em habitações de doentes imunocomprometidos ou outras populações susceptíveis.
- Characterization of the bioburden in green tea samples marketed in LisbonPublication . Viegas, Susana; Twarużek, Magdalena; Kosicki, Robert; Grajewski, Jan; Santos, Patrícia; Sá, Flávio; Mateus, Margarida; Viegas, CarlaTea is one of the most consumed beverages in the world essentially because of its beneficial effects on health. There are no regulations or load limits concerning microbial contamination of teas, and for this reason, microbiological food safety hazards linked with these products have rarely been reported. The aim of this study was to assess the bioburden of loose and bags tea of green tea marketed in Lisbon, after and before boiling following the ISO 7218 (2007) and ISO 3103 (1980). Twenty samples of green tea from loose and bag tea (ten of each) were select from different markets in Lisbon. For microbiological evaluation was carried out the extraction of the samples before and after the boiling. For samples that did not have manufacturer confection indications were followed by ISO 7218_2007. The samples were inoculated on two media: dichloro-glycerol agar (DG18) and Rose Bengal Chloramphenicol (RBC) incubated for 5 days at 25ºC. All tea samples will be screened for mycotoxins presence. Regarding fungal contamination in tea bags, before boiling, ranged from 0 to 66.67 CFU.g-1 in DG18, and from 0 to 84.85 CFU.g-1 in RBC medium. In tea bags, all brew samples present 0 CFU.mL-1 for the two medium. For loose tea before boiling, the fungal contamination ranged from 0 to 96.97 CFU.g-1, and after boiling ranged from 0 to 30.3 CFU.mL-1 in DG18. In RBC, before boiling, the fungal concentration ranged from 0 to 72.73 CFU.g-1 and the brew samples presented 0 CFU.mL-1 or were below the limit of determination after boiling. In loose tea samples, before boiling, the DG18 media show five different fungal genera/species and the most prevalent were Chrysosporium sp. (38.46%), Aspergillus section Nigri (30.76%) and section Versicolores (11.5%), whereas in RBC media two different fungal species were found, Aspergillus section Nigri (80%) and Penicillium sp. (20%). After boiling only the DG18 presented fungal contamination: Mucor sp. (80%) and Chrysonilia sitophila (20%). Concerning tea bags samples, before boiling, Aspergillus section Nigri was the most prevalent fungi in both media (90.47% DG18; 90.62% RBC). None of the bag samples showed fungal contamination after boiling. This study showed that after boiling was observed reduction of viable microorganisms, revealing that boiling is effective to reduce most bioburden present in the tea before boiling. However, due to the presence of toxigenic species in the tea before boiling and the well-known mycotoxins thermal resistance, mycotoxins data will be of interest to consider a more accurate risk assessment.
- Commercial green tea from Portugal: comprehensive microbiologic analysesPublication . Viegas, Carla; Sá, Flávio; Mateus, Margarida; Santos, Patrícia; Almeida, Beatriz; Aranha Caetano, Liliana; Gomes, Anita Q.; Viegas, SusanaIn recent times green tea (GT) consumption has increased, due to the numerous studies that indicate a wide variety of health benefits following its regular consumption. The aim of this study was to assess the bioburden (bacteria and fungi) of bulk and bags of GT marketed in Lisbon and to obtain a more refined fungal burden characterization, including azole resistance profile. The bacteriota in tea bags before boiling ranged from lower than the detection limit to 1770 CFU.g−1, whereas in brew samples ranged from lower than the detection limit to 54.55 CFU.mL−1. In bulk samples before boiling ranged from lower than the detection limit to 2636 CFU.g−1, while after boiling ranged from lower than the detection limit to 72.73 CFU.mL−1. Fungal contamination on teabags before boiling ranged from lower than the detection limit to 66.67 CFU.g−1 and after boiling, all samples presented results lower than the detection limit. Concerning bulk samples before boiling ranged from lower than the detection limit to 96.97 CFU.g−1, whereas after boiling ranged from lower the detection limit to 30.3 CFU.mL−1. Before boiling, the most common fungal species in the bagged tea (90.91 CFU.g−1; 45.45%) and bulk samples (66.67 CFU.g−1; 91.67%) was Aspergillus section Nigri. Fungal diversity was higher on bulk samples than in tea bags. Aspergillus section Nigri and Rhizopus sp. growth was observed mostly on itraconazole-supplemented Sabouraud dextrose agar media, which require further investigation. Aspergillus sections Fumigati and Nidulantes were detected by using real-time PCR, but not in the GT samples in which they were identified through culture-based methods. A significant reduction of bacterial contamination after boiling was observed, however fungal contamination with toxigenic potential was observed before and after boiling. Future research work needs to characterize in detail the mycotoxins contamination to allow a risk-benefit assessment to estimate the human health benefits and risks following tea consumption and to support policy actions, if and when needed. The results also suggest that the conditions of how tea is packed can influence the fungal diversity and this variable should be further investigated.
- Volatile organic compounds mixtures in hospital environment: the common exposure scenarioPublication . Viegas, Susana; Mateus, MargaridaChemical contamination is a reality in the hospital environment but unfortunately is rarely studied. However, if we consider that healthcare workers use a high diversity of products such as disinfectants, sterilizers, anesthetic gases, and much other is easy to recognize that workers and patients can be exposed to a complex mixture of chemicals. The aim of this study was to determine, through a review, the presence of volatile organic compounds (VOCs) mixtures in a hospital environment. Results showed that a complex mixture of VOCs is normally present and this aspect should be reflected in the risk assessment process. Future research work must be developed related to the possible health effects caused by exposure to complex mixtures of chemicals.