# In vitro susceptibility profiles of invasive Candida bloodstream isolates to ten antifungal drugs in a southern area of China

## TL;DR

This study examines the drug resistance of Candida bloodstream infections in southern China to guide better antifungal treatment choices.

## Contribution

The study provides updated in vitro susceptibility data for ten antifungal drugs against Candida bloodstream isolates in a specific Chinese region.

## Key findings

- Candida albicans was the most common bloodstream isolate, followed by C. parapsilosis, C. glabrata, and C. tropicalis.
- Echinocandins and amphotericin B showed the highest susceptibility across Candida species.
- C. parapsilosis and C. tropicalis exhibited high resistance to azole drugs like itraconazole and posaconazole.

## Abstract

Introduction. In recent years, with the increase of drug resistance of Candida, the incidence rate and mortality of candidemia have gradually increased, which has brought a huge economic and health burden to people.

Gap Statement. The epidemiological characteristics and antifungal drug sensitivity patterns in different regions have varied.

Aim. To analyse the distribution and antifungal susceptibility of Candida strains isolated from bloodstreams and provide a basis for the use of antifungal drugs for treatment.

Methodology. A total of 115 strains of Candida were collected from the bloodstream, and 28 strains of colonized Candida albicans were collected from the upper respiratory tract. Candida species were identified using matrix-assisted laser desorption/ionization time-of-flight technology. Antifungal susceptibility was assessed using broth microdilution combined with redox methods.

Results. There were eight types of Candida strains isolated from the bloodstream; C. albicans was the most common species (36.5%), followed by Candida parapsilosis (24.3%), Candida glabrata (17.4%) and Candida tropicalis (14.8%). There was no significant difference in the resistance of C. albicans to azole drugs between the bloodstream infection group and the upper respiratory tract colonization group, but there was a significant difference in the MIC values of micafungin and fluconazole, with P values of 0.017 and 0.003, respectively. Amphotericin B and echinocandins are the most susceptible drugs for all Candida species, but the MICs of echinocandins against C. parapsilosis are significantly higher than those of other Candida species. Candida (except for C. glabrata) is highly resistant to azoles, with C. parapsilosis showing resistance rates of 89.3% and 82.1% to itraconazole and posaconazole, respectively; the resistance rates of C. tropicalis are 100% and 94.1%, respectively.

Conclusion.C. albicans remains the predominant pathogen responsible for candidemia. Although the resistance of Candida to antifungals is relatively stable, there are significant differences in the MICs of antifungal drugs against Candida, indicating the importance of strain identification in the treatment of candidemia. For empirical treatment, the use of echinocandin drugs is recommended.