| Congresso Brasileiro de Microbiologia 2023 | Resumo: 464-2 | ||||
Resumo:INTRODUCTION: One Health investigations have highlighted the pivotal role of the environment-community interface in the emergence of novel pathogens. This phenomenon is not solely driven by human activity but also the interplay between organisms and environmental factors. Therefore, it is essential to study ubiquitous environmental pathogens, such as Free-Living Amoebas (FLAs), known for their intrinsic virulence and interactions with diverse microorganisms including pathogenic fungi. These interactions play a crucial role in the selection and expression of virulence factors, making them of utmost importance. Furthermore, their coexistence with pathogens responsible for hospital outbreaks, like yeasts of the Candida haemulonii/auris complex, in soil and water sources, raises significant concerns. Hence, Rigorous studies exploring the interactions between FLAs and yeasts are necessary to elucidate key mechanisms driving their coexistence and potential influence on pathogenicity.
METHODS: A comprehensive investigation was conducted, encompassing a year-long water collections from distinct beaches, subject to diverse uses by the population in the city of Niterói, to observe the colonization patterns of potential pathogens in these natural aquatic habitats. Water samples were concentrated and cultivated on a selective medium to detect pathogenic yeasts. Subsequently, the colonies were identified by MALDI-TOF, revealing distinctive diversity profiles across the various niches.
RESULTS: Jurujuba and Icaraí harbored 17 yeast species each, while Piratininga hosted 12 species, with exclusive and different dominant species in each site. The Candida genus comprised most species, with C. parapsilosis displaying highest prevalence across all beaches, despite the seasonal variations for its detection and other species. Additionally, intriguing intraspecific divergences in thermotolerance were identified, both among isolated yeast strains and across the beaches, with optimal growth temperatures ranging from 28ºC to 42ºC. Isolates exhibiting more exuberant growth at 37ºC and 42ºC were primarily attributed to C. parapsilosis, C. guilliermondii, and C. tropicalis, corresponding respectively to Jurujuba and Icaraí beaches, characterized by heightened anthropogenic influence. Furthermore, the sensitivity levels of these isolates to clinically used antifungal drugs are currently under assessment.
CONCLUSIONS: These findings have provided valuable insights into the potential underlying factors contributing to the emergence of novel pathogens and how anthropic actions, alongside interactions with other environmental pathogens, may influence this phenomenon. The concurrent detection of both FLAs and yeasts within the same environmental isolate holds promise for studying their interactions, given the presence of pathogenic FLAs (such as Acanthamoeba spp., Balamuthia spp., and Naegleria spp., under assessment) and Candida species in aquatic environments. Understanding the dynamics between these organisms could lead to effective strategies to improve the sanitary quality of aquatic environments, benefiting public health and ensuring the preservation of these crucial ecosystems. These insights will empower informed decision-making by public managers, thus safeguarding the health and sustainability of these vital ecosystems.
Palavras-chave: Candida, environmental interaction, free-living amoeba, water Agência de fomento:CAPES; CNPQ; FAPERJ; PROPPi/UFF | |||||