Dados do Trabalho

Título

Screening of Candida spp. in wastewater in Brazil during COVID-19 pandemic: Workflow for monitoring fungal pathogens

Introdução

Fungal diseases are often linked to poverty, which is associated with poor hygiene and sanitation conditions that the COVID-19 pandemic has severely exacerbated. Additionally, these patients are treated with dexamethasone, increasing their susceptibility to opportunistic fungal infections, such as those caused by Candida species. The One Health framework integrates the public health, veterinary, and environmental sectors. It is particularly relevant for Mycology since it concerns controlling zoonotic diseases, managing pollution, combating antimicrobial resistance, and the role of the environment as an influencing factor in the emergence and re-emergence of fungi potentially pathogenic species.

Objetivo (s)

The present study seeks to carry out a screening of yeasts and Sars-CoV-2 in wastewater, observing their biological diversity and pathogenicity profiles. Also, we propose a workflow for quick and accurate identification of environmental samples, using polyphasic taxonomy.

Material e Métodos

Yeasts from sewage samples were isolated, quantified, and identified macro, microscopical, and biochemical characteristics, followed by molecular identification (ITS sequencing and MALDI-TOF-MS). To evaluate the production of hydrolytic enzymes, 10 µL of fungal cell suspension were taken at a concentration of 1x107 cells/mL, stained on the surface of specific agar medium, and the production of hydrolytic enzymes was expressed as Pz (a/b) value. To verify biofilm formation 200µL of the cell was incubated, and after removing the supernatant biofilms were fixed.

Resultados e Conclusão

Macroscopic aspects of the colonies revealed that all isolates are different species belonging to Candida genera. C. albicans was suggested as a species only in one isolate. The biochemical analysis frequent species were C. parapsilosis and C. famata. However, when performing molecular analysis by MALDI-ToF and ITS sequencing, the most frequently identified species was C. palmioleophila. Regarding the production, Five isolates were good producers of Aspartic Protease/ Calcium Phytate, ten were good Esterase producers and none of the samples was able to produce Phospholipase. One C. palmioleophila and C. tropicalis isolates presented higher mean absorbance values of the biomass produced.

Palavras Chave

Candida species; emergent fungi; polyphasic taxonomy; fungal virulence factors; COVID-19.