Banca de DEFESA: LORENA SOUZA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LORENA SOUZA SILVA
DATE: 13/03/2025
TIME: 09:00
LOCAL: Google Meet https://meet.google.com/yoh-ejiq-haj
TITLE:

FROM ENVIRONMENT TO HOST: RESISTANCE IN YEASTS FROM A UNIQUE HEALTH
PERSPECTIVE

 

KEY WORDS:

Candida spp., Kodamaea, Fungal resistance, Cross-resistance,
Environmental antifungals.

 

PAGES: 98
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUMMARY:

The resistance to antifungals has been increasing in fungi, especially in the
groups that cause invasive mycoses. Usually, resistance selection occurs due to prior treatment with
antifungals. However, there are reports of infections caused by fungi that are already resistant, without
prior exposure to antifungals. This finding raises the hypothesis that the process of acquiring resistance
may occur in the environment, possibly selected by antimicrobials with antifungal effects, such as
environmental fungicides and hospital disinfectants. Thus, the objective of this study was to investigate the
drug resistance profile with antifungal activity in medically important yeasts found infecting/colonizing patients, in animals, and in the environment, testing the hypothesis of cross-resistance between clinical and
environmental antifungals. Yeasts were isolated from different sources and identified by mass
spectrometry (MALDI-TOF MS). A total of 135 isolates were identified, with a prevalence of the following
genera: (i) Candida (101; 74.8%), (ii) Kodamaea (17; 12.6%), (iii) Cryptococcus (7; 5.2%), and (iv)
Trichosporon (5; 3.6%). After identification, the sensitivity profile of the isolates was determined through
the Minimum Inhibitory Concentration (MIC) test using the broth microdilution method with clinical
antifungals, environmental antifungals, and hospital disinfectants. In total, the Candida genus exhibited
9.6% resistance to clinical antifungals. The highest resistance was attributed to Micafungin (6.9%) and
occurred in Candida glabrata. Four multi-resistant isolates to Amphotericin B and Micafungin were also
found, and one isolate exhibited multi-resistance to Fluconazole and Amphotericin B. The highest efficacy
among environmental antifungals was attributed to Tebuconazole, inhibiting 77% of the isolates. An isolate
exhibiting resistance to both Fluconazole and Tebuconazole was identified, in addition to demonstrating
high MIC values for hospital disinfectants. In summary, this study provides data on antifungal resistance in
yeasts collected from different environments in the State of Rio Grande do Norte (RN), contributing to the
clarification of the multifactorial relationship of the emergence of resistant yeast isolates of clinical
importance.

 

 

COMMITTEE MEMBERS:
Externa à Instituição - DANIELLE LETÍCIA DA SILVA - UFMG
Externa à Instituição - JULLIANA RIBEIRO ALVES DOS SANTOS - UPE
Presidente - 1143204 - RAFAEL WESLEY BASTOS