Predominance of Non-albicans Candida, High Virulence, and Fluconazole Resistance in Clinical Isolates: A Cross-Sectional Study

Abstract

Background: Invasive and mucocutaneous Candida infections are increasingly
attributed to non-albicans Candida species, with variable antifungal resistance and
virulence traits. This study aimed to assess the distribution, virulence characteristics,
and antifungal susceptibility of Candida isolates from clinical specimens in a tertiary
care setting.
Methods: A cross-sectional study was conducted over six months at a tertiary
hospital in Chennai. Fifty-two Candida isolates from various clinical specimens were
identified to the species level using germ tube testing, CHROMagar, sugar
fermentation, and assimilation. Virulence factors (proteinase, phospholipase, and
biofilm formation) were assessed phenotypically. Antifungal susceptibility testing to
fluconazole and voriconazole was performed using the disc diffusion method
according to CLSI guidelines.
Results: Of the 52 isolates, 42.3% were C. tropicalis, 34.6% C. albicans, 11.5% C.
parapsilosis, 7.7% C. glabrata, and 3.8% C. krusei. The majority of isolates (65.4%)
were non-albicans Candida. Isolates were most frequently obtained from
catheterized urine (34.6%), followed by blood and respiratory samples. Virulence
factor analysis showed proteinase production in 73% and phospholipase in 46% of
isolates. Biofilm formation was common among urinary isolates. All species showed
100% sensitivity to voriconazole, while 28.8% of isolates were resistant to
fluconazole, particularly among C. tropicalis and C. glabrata.
Conclusions: Non-albicans Candida species predominate in clinical infections and
demonstrate significant virulence traits and fluconazole resistance. Routine specieslevel identification and antifungal susceptibility testing are essential to guide
effective therapy.