Ciência no Ecrã (Science on the Screen) é o novo Ciclo de Seminários Online do Departamento de Biologia, onde cientistas convidados falam de ciência e dão a conhecer os seus trabalhos de investigação em cerca de 30 minutos. A segunda temporada irá decorrer quinzenalmente, à segunda-feira, até ao final de março de 2021.
Raquel Sabino - Instituto Nacional Ricardo Jorge (INSA)
08 Mar | 12:00 | videoconf link
Resumo/Abstract
There is still a lack of knowledge about the epidemiology of fungal infections worldwide, since the report of those infections is not mandatory. On the other hand, the epidemiology of fungal infections has been changing with the emergence of new etiological agents, and the emergence of resistances. Aspergillus and Candida species are the most frequent etiological agents of fungal infections in immunocompromised patients. Aspergillusis the filamentous fungi more frequently associated with invasive fungal infection. According to the LIFE organization, more than 30 million patients are at risk for invasive aspergillosis and about 300,000 patients will develop the disease annually. As ubiquitous organisms, Aspergilluss pp. are easily cultured from air (both indoor and outdoor), water, soil, sand, and vegetation. Similarly, aspergilli can be present in hospital environments. Diseases caused by spp. are diverse and include mycotoxicosis, allergy, and invasive infections. Invasive infections depend on the interplay between host susceptibility and environmental exposure to the conidia. More than 400 species of Aspergillushave been described. These are organized into subgenera and sections and molecular approaches are needed to identify cryptic species (to achieve the correct identification to species level). Despite the intrinsic resistances found in some Aspergillusspecies, exposure of fungi to antifungal agents via medical or agricultural use of these compounds commonly appears to have a major impact on acquisition of resistance to azoles by Aspergillus fumigatus. This highlights the importance of establishing surveillance programs for Aspergillus antifungal susceptibility from different sources. Therefore, a retrospective laboratory-based study (2017-2018) on Aspergillussurveillance was performed at the national mycology reference laboratory of Portugal. The primary objective were the knowledge of the molecular epidemiology of clinical and environmental Aspergillus isolates. A. fumigatus sensu stricto was the most frequent species in both clinical and environmental sources. A very high frequency of cryptic species was identified. A second objective was the determination of the frequency of azole resistance of A. fumigatus. All isolates included in our collection (2012-2019) identified as belonging to Fumigati section were recovered and screened. The overall frequency of resistance to azoles in A. fumigatus sensu stricto was 3.0% (four clinical and five environmental isolates). The TR34/L98H mutation, linked to environmental transmission route of azole resistance the most frequently detected mutation, found in three environmental and one clinical isolate (1.4%).
