Antifungal susceptibility and virulence factors of Candida species isolated in patients from Porto Velho, Rondônia, Brazilian Amazon

Candida species normally colonize the human body in a commensal manner, however, under conditions of immunosuppression or host imbalance, they can cause opportunistic infections, including systemic forms, which are frequently associated with high mortality rates. This study evaluated the antifungal susceptibility profiles and virulence factors of Candida species isolated from patients in Porto Velho, Rondônia, Brazilian Amazon. A total of 31 isolates collected between April 2021 and March 2022 at the Medical Mycology Laboratory of the Tropical Medicine Research Center of Rondônia were analyzed. Identification was done by cultivation on CHROMagar and sequencing of the ITS region of rDNA. Susceptibility testing was conducted by the disk diffusion method using fluconazole, itraconazole, miconazole, amphotericin B, and nystatin. Hemolysin and phospholipase activities were also assessed. Most isolates were C. albicans (71%), followed by C. tropicalis (19.4%), C. parapsilosis, C. duobushaemulonii, and Cyberlindnera jadinii (3.2% each). The majority of samples came from sputum (64.5%), followed by skin scales (19.4%) and nails (9.7%). Candidiasis was more frequent in males (51.6%), especially between 40 and 59 years of age, with risk factors including comorbidities (71%), antibiotic use (61.2%), and invasive devices (58%). High resistance rates were observed to fluconazole (86.7%) and itraconazole (80%), with lower resistance to amphotericin B (13.3%) and nystatin (10%). C. tropicalis and C. parapsilosis exhibited concerning resistance profiles. All isolates produced hemolysin, while phospholipase activity was detected in C. albicans and C. jadinii. The associated mortality rate was 13%. These data emphasize the importance of local epidemiological surveillance to guide clinical management and prevention of candidiasis in the Amazon region.