# Species Distribution and Antifungal Susceptibility Patterns of Invasive Candidiasis in a Belgian Tertiary Center: A 7-Year Retrospective Analysis

## TL;DR

This study analyzed the spread and drug resistance of Candida species causing invasive infections at a Belgian hospital over seven years.

## Contribution

The study provides updated local epidemiological data on Candida species and antifungal resistance patterns in a tertiary center.

## Key findings

- Candida albicans was the most common species, with high fluconazole susceptibility.
- Nakaseomyces glabratus and Candida tropicalis showed significant fluconazole resistance.
- Echinocandins and amphotericin B remained highly effective across all species.

## Abstract

Candidiasis is a major fungal infection worldwide, with invasive forms linked to high morbidity and mortality. The emergence of azole resistance in Candida parapsilosis causing candidemia led us to examine the epidemiology and antifungal susceptibility of Candida species at the University Hospital of Liège between January 2017 and December 2023. A total of 916 isolates from blood or sterile body fluids, tissues, and abscesses were analyzed. Species identification was performed using MALDI-TOF MS and antifungal susceptibility testing via Sensititre YO10 AST was interpreted according to the CLSI guidelines. Candida albicans remained the predominant species (56%), followed by Nakaseomyces glabratus (19%), Candida parapsilosis (8%), and Candida tropicalis (7%). No significant shift toward non-albicans Candida species (NAC) was observed even during the COVID-19 pandemic, supporting the use of narrow-spectrum empirical therapy in selected patients. Fluconazole susceptibility was high in C. albicans (98.8%), whereas N. glabratus and C. tropicalis showed high resistance rates with 10.1% and 16.9%, respectively. C. parapsilosis showed stable fluconazole susceptibility across the study period. Echinocandins demonstrated excellent activity (95.6–100%), and amphotericin B was effective against nearly all isolates. This seven-year surveillance at the University Hospital of Liège confirms that while C. albicans remains the predominant and highly susceptible species, rising azole resistance in non-albicans Candida—particularly N. glabratus and C. tropicalis—highlights the critical need for ongoing local epidemiological monitoring to guide effective and targeted antifungal therapy.