Antibiofilm Activity of Essential Fatty Acids Against Candida albicans from Vulvovaginal Candidiasis and Bloodstream Infections

Abstract

Purpose

The biofilm formation of Candida albicans is an important virulence factor as it can increase tolerance to conventional antifungal drugs and the host immune system. The study aimed to assess the effect of essential fatty acids (EFAs) against biofilm formation and mature biofilms of C. albicans strains, which were isolated from vulvovaginal candidiasis and candidemia.

Methods

The biofilm formation ability of C. albicans and antifungal activities of fluconazole were determined. Additionally, the effects of six EFAs [α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LOA), γ-linolenic acid (GLA), and arachidonic acid (AA)] against C. albicans under planktonic and biofilm conditions were evaluated.

Results

94.1% of C. albicans exhibited biofilm formation capacity, and 98.5% of C. albicans were susceptible to fluconazole. The biofilms of C. albicans were highly resistant to fluconazole with minimum biofilm eradication concentration values ≥ 64 µg/mL. The EFAs attenuated biofilm formation in a dose-dependent manner, and GLA displayed a remarkable inhibitory activity against biofilm formation of C. albicans. In addition, EPA, DHA, and GLA at 0.1 mM could inhibit the biofilm formation of C. albicans without affecting the planktonic growth rate. Notably, EPA and AA at 1 mM had both inhibitory and eradication activities on C. albicans biofilms.

Conclusion

This is the first study to directly compare different EFAs for their capacity to affect C. albicans biofilm formation as well as biofilm eradication. These results suggest EPA and AA could serve as potential new antifungal agents for the treatment of clinical infections caused by C. albicans biofilms.

Keywords:

• Candida albicans
• polyunsaturated fatty acids
• biofilm
• inhibition
• eradication

Ethical Approval

This study has been approved by the Ethics Committee of Beijing Chao-Yang Hospital, Capital Medical University (2021-2-26-3). Individual informed consent was waived by the ethics committee listed above because this study used the currently existing samples collected during routine medical care and did not pose any additional risks to the patients. This study was conducted in accordance with the Declaration of Helsinki.

Acknowledgments

The authors would like to thank all staff members of the Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital (Beijing, China), for their contribution to this work.

Supplementary Materials

Table S1 The biofilm inhibition rates (%) of essential fatty acids (EFAs) and fluconazole against C. albicans strains; Table S2 The biofilm eradication rates (%) of essential fatty acids (EFAs) and fluconazole against C. albicans strains.

Disclosure

The authors report no conflicts of interest in this work.