In vitro development of resistance to nystatin by Candida albicans and Torulopsis glabrata

Area of Science:

• Medical Mycology
• Antifungal Resistance
• Microbial Genetics

Background:

• Nystatin is a crucial antifungal agent used to treat infections caused by yeasts.
• Understanding the development of antifungal resistance is essential for effective treatment strategies.
• Torulopsis glabrata and Candida albicans are significant human fungal pathogens.

Purpose of the Study:

• To investigate and compare the levels of nystatin resistance induced in Torulopsis glabrata and Candida albicans.
• To explore the potential for rapid development of antifungal drug resistance in these yeast species.

Main Methods:

• Induction of drug resistance through serial subculturing in the presence of increasing nystatin concentrations.
• Determination of minimum inhibitory concentrations (MICs) for nystatin against multiple strains of both yeast species.

Main Results:

• Torulopsis glabrata strains developed high-level nystatin resistance (MICs > 20,000 U/mL).
• Candida albicans strains exhibited significantly lower nystatin resistance (MICs ≤ 2,000 U/mL).
• A notable difference in induced resistance levels was observed between the two species.

Conclusions:

• Torulopsis glabrata demonstrates a propensity for rapid acquisition of high-level nystatin resistance.
• The findings suggest a potentially higher spontaneous mutation rate conferring nystatin resistance in Torulopsis glabrata compared to Candida albicans.
• This highlights the importance of monitoring antifungal resistance in clinical settings.