# Molecular Identification, Virulence Factors, and Antifungal Susceptibility Profiles of Candida Isolates from Clinical Samples of Intensive Care Patients

## TL;DR

This study analyzed 100 Candida isolates from ICU patients to identify species, assess virulence factors, and test antifungal susceptibility for better treatment strategies.

## Contribution

The study provides a comprehensive analysis of species distribution, virulence factors, and antifungal susceptibility in ICU-derived Candida isolates.

## Key findings

- C. albicans and non-albicans species showed distinct antifungal susceptibility trends, with higher fluconazole MICs in C. albicans.
- MALDI-TOF MS outperformed Chromagar in species identification accuracy.
- Most isolates exhibited hemolytic activity, while protease and biofilm formation were also common virulence traits.

## Abstract

Background/Objectives:  Candida infections constitute a significant category of healthcare-associated infections. In studies aiming to develop new antifungal agents against Candida species, the importance of their virulence factors has been emphasized. Methods: This study included 100 Candida isolates obtained from patients hospitalized in intensive care units. Standard microbiological and molecular methods were employed for species identification. Virulence factors were determined through protease, phospholipase, hemolysis, and biofilm activity assays per-formed on the Candida strains. The EUCAST liquid microdilution method was used to assess antifungal susceptibility. Results: Based on sequencing results, 39 isolates were identified as Candida albicans and 61 as non-albicans Candida species. The accuracy of species identification was found to be 71% for Chromagar Candida and 87% for the MALDI-TOF MS system, compared to sequencing. Protease activity was positive in 52% of the isolates, phospholipase in 42%, hemolytic activity in 77%, and biofilm formation in 48%. Kruskal–Wallis analysis revealed no statistically significant interspecies differences in MIC distributions for amphotericin B, fluconazole, itraconazole, or nystatin (p > 0.05), although species-specific trends were observed, with higher fluconazole MICs in C. albicans and lower MIC values in C. tropicalis.  Conclusions: Determining the distribution of Candida species, as well as their virulence factors and antifungal MIC profiles, is of great importance for developing appropriate treatment strategies and reducing related morbidity and mortality.