Identificação molecular e perfil de suscetibilidade a antifúngicos de Aspergillus obtidos de solos expostos e isentos de azólicos no estado de Mato Grosso do Sul

• Ano de defesa: 2022
• Autor(a) principal: Dorneles, Francine de Sales
• Orientador(a): Melhem, Marcia de Souza Carvalho
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso do Sul
• País: Brasil
• Palavras-chave em Português: Triazol; Fungicida; Antifúngico
• Link de acesso: https://repositorio.ufms.br/handle/123456789/4755

The occurrence of therapeutic failure with drugs of the azole class, in patients with invasive aspergillosis, is a challenge in medical practice. Host predisposing factors and antifungal resistance of the infecting strain are important actors in this scenario. Resistance in Aspergillus, a ubiquitous fungus in nature, is attributed to two exposure routes: clinical, by long-term treatments, or environmental, by previous contact with triazole fungicides used in agriculture to control phytopathogenic fungi. Resistance mutations, responsible for resistance to azoles, activities in environmental and clinical strains, reinforcing a hypothesis: resistance between drugs and pesticides. The study, descriptive and prospective, investigated the frequency of resistance to triazoles in environmental species of Aspergillus in the state of Mato Grosso do Sul and environmental exposure to fungicides. Crops (n=9), characterizing the sprayed environment, and agroforests (n=3), representing the spraying environment, located in seven municipalities in the state were sampled by opportunity criterion. Soil samples (n=61) were processed and seeded in DRBC medium and provided isolation of 131 Aspergillus colonies, classified by morphological analysis, in four sections, Fumigati (50%), Nigri (18%), Terrei (16%) and Flavi (16%). A. species by benA gene sequencing was performed in identification of 68 isolates, a. identification of 10 species: A. fumigatus (50%), A. terreus (10%), A. niger (10%), A. flavus (9%), A. alabamensis (6%), A. tubingensis (4 %), A. tamarii (3%), A. caelatus (2%), A. parasiticus (3%) and A. brasiliensis (3%). The sensitivity of the isolates to 3 drugs, itraconazole (ITC), voriconazole (VCZ), posaconazole (POS) and 2 triazole fungicides, tebuconazole (TEB) and difenoconazole (DIF) was determined by the MIC value, according to procedures and cut-off points, epidemiological and clinical, of the EUCAST committee. Resistant isolates, or non-wild (NWT), azoles were found in high frequency (92.6%) and in all species, with emphasis on multi-resistance to ITC, VCZ and POS in three isolates of A. fumigatus. Soil from traditional crops was the source of greater resistance (37%), in relation to agroforestry (29%). A. fumigatus resistant to azoles were recovered more frequently from crops than from agroforests. The existence of an environmental resistance route in aspergillosis agents has been proven in the state of MS. However, their relationship to the use of azole fungicides for agricultural use was not evidenced, leaving open the question of the impact of fungicides on the selective pressure of resistance in Asperillus.