Fatores de virulência e o perfil de sensibilidade aos antifúngicos de isolados clínicos de Candida albicans de pacientes soropositivos e soronegativos para HIV: estudo experimental in vitro

Abstract

Fungal infections, especially those of the Candida genus, have become a global concern due to increasing virulence and antifungal resistance. Factors such as medical advancements, longer life expectancy, overuse of antimicrobials, and climate change contribute to their expansion, highlighting the importance of identifying virulence factors for early diagnosis and effective treatment. This work aimed to analyze virulence factors and the antifungal susceptibility profile of clinical isolates of Candida albicans from HIV-seropositive and -seronegative patients, in order to identify possible differences in resistance and fungal invasiveness between the groups. Candida albicans samples from HIV-seropositive and -seronegative patients were subcultured on Potato Dextrose Agar (PDA) at 35°C for 24 hours prior to testing. After growth, the cultures were adjusted to a concentration of 1x106 CFU/mL and inoculated into Petri dishes containing the culture media indicated for each test. Virulence factors related to thermotolerance, morphogenesis, phospholipase and proteinase production, germ tube formation, and biofilm production were analyzed. Furthermore, the sensitivity profile to the antifungals amphotericin B (AnfB) and fluconazole was evaluated using the broth microdilution technique, following standardized protocols. After appropriate laboratory analyses of the in vitro tests, it was possible to verify that there was no statistically significant difference in the virulence factors expressed by Candida albicans between the different groups included in the study. However, when compared to the ATCC control strain, there was a statistically significant difference in biofilm formation. After profiling the sensitivity of fluconazole and amphotericin B, it was found that the samples presented a higher MIC for fluconazole, which differed when evaluating amphotericin B, which presented MIC at lower concentrations of the drug. It can be concluded a diversity of factors with pathogenic potential expressed by Candida albicans can be observed, highlighting the importance of understanding the mechanisms related to pathogenicity and antifungal resistance. Future studies are needed to evaluate other forms of virulence and other antifungal drugs.