Browsing by Author "Morais, Susana"
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- Comparison of Multi-locus Genotypes Detected in Aspergillus fumigatus Isolated from COVID Associated Pulmonary Aspergillosis (CAPA) and from Other Clinical and Environmental SourcesPublication . Morais, Susana; Toscano, Cristina; Simões, Helena; Carpinteiro, Dina; Viegas, Carla; Veríssimo, Cristina; Sabino, RaquelBackground: Aspergillus fumigatus is a saprophytic fungus, ubiquitous in the environment and responsible for causing infections, some of them severe invasive infections. The high morbidity and mortality, together with the increasing burden of triazole-resistant isolates and the emergence of new risk groups, namely COVID-19 patients, have raised a crescent awareness of the need to better comprehend the dynamics of this fungus. The understanding of the epidemiology of this fungus, especially of CAPA isolates, allows a better understanding of the interactions of the fungus in the environment and the human body. Methods: In the present study, the M3 markers of the STRAf assay were used as a robust typing technique to understand the connection between CAPA isolates and isolates from different sources (environmental and clinical-human and animal). Results: Of 100 viable isolates that were analyzed, 85 genotypes were found, 77 of which were unique. Some isolates from different sources presented the same genotype. Microsatellite genotypes obtained from A. fumigatus isolates from COVID+ patients were all unique, not being found in any other isolates of the present study or even in other isolates deposited in a worldwide database; these same isolates were heterogeneously distributed among the other isolates. Conclusions: Isolates from CAPA patients revealed high heterogeneity of multi-locus genotypes. A genotype more commonly associated with COVID-19 infections does not appear to exist.
- Genotipagem de isolados de Aspergillus fumigatus de origem clínica e ambientalPublication . Morais, Susana; Sabino, Raquel; Barata, MargaridaAspergillus fumigatus é um fungo sapróbio, ubíquo no ambiente, com crescente importância clínica para a saúde humana, pois é responsável por provocar, entre outras patologias, infeções invasivas graves, especialmente em indivíduos imunocomprometidos. Dada a elevada taxa de mortalidade associada às infeções relacionadas com este fungo, bem como a emergência de um grave problema de resistência aos antifúngicos triazóis utilizados como primeira linha de tratamento nestas, torna-se importante perceber a sua dinâmica no ambiente e no organismo humano. Além disso, o aparecimento de novos grupos de risco aos quais a infeção está associada, tem vindo a levantar também uma crescente preocupação no que toca aos critérios para diagnóstico e tratamento da doença, que ainda representam um desafio. O conhecimento da epidemiologia do fungo permite uma melhor perceção das suas interações com o ambiente e com o Homem, tornando esta área de elevada importância no contexto da relevância crescente de Aspergillus fumigatus na clínica. No presente estudo, foi utilizada uma técnica robusta de genotipagem, específica para Aspergillus fumigatus sensu stricto, o ensaio STRAf, que permite distinguir diferentes estirpes desta espécie, através da amplificação de loci específicos numa reação de amplificação multiplex com primers marcados com fluorescência. Com o ensaio realizado foi possível comprovar a grande variabilidade genética de Aspergillus fumigatus, tendo-se observado 85 genótipos de entre os 100 isolados viáveis analisados. Foi também possível perceber a interação entre alguns dos isolados em estudo. A técnica revelou, como esperado, um elevado poder discriminatório (0,9820) o que confirma a sua utilidade em futuros estudos epidemiológicos de grande escala, essenciais para melhor entender como abordar a problemática crescente que este fungo tem representado.
- Multilocus genotyping of Aspergillus fumigatus isolated from patients diagnosed with COVID Associated Pulmonary Aspergillosis (CAPA)Publication . Morais, Susana; Toscano, Cristina; Simões, Helena; Carpinteiro, Dina; Viegas, Carla; Verissímo, Cristina; Sabino, RaquelAspergillus fumigatus is an environmental fungus responsible for causing severe invasive infections, especially in immunocompromised individuals. In 2020, during SARS-CoV-2 pandemics, a high number of cases of pulmonary aspergillosis was detected in COVID-19 patients, leading to the definition of CAPA (COVID-19 associated pulmonary aspergillosis). Patients with CAPA harbor many baseline prognostic factors with negative effects on survival, which might be further compromised by azole-resistant Aspergillus isolates. With the purpose of understanding the diversity of A. fumigatus isolates collected from CAPA patients, we applied a multilocus genotyping methodology (STRAf assay), using three trinucleotide microsatellite markers (99% discriminatory power) to 100 A. fumigatus isolates from different sources. From the isolates analyzed during the study, 85 multilocus genotypes were found. A high diversity of genotypes in CAPA isolates was observed. However, some of those isolates shared genetic similarity since they were collected from patients in the same hospital. Given the ubiquity of A. fumigatus, it is likely that patients may have shared the same contamination source within the hospital environment. In other isolates several multilocus genotypes were shared, reinforcing studies in the One Health Context. In conclusion, CAPA is yet poorly understood due to the lack of studies including isolates collected from COVID patients. Thus, molecular analysis of genetic and epidemiological relationship between those isolates may allow us to assess their potential origin and transmission routes.