Histatin 5 and human lactoferrin inhibit biofilm formation of a fluconazole resistant Candida albicans clinical isolate

Abstract:Candida albicans is the most important fungal pathogen that causes infections in humans. Biofilms are hard-to-treat structures due to their high antifungal resistance. Saliva is a fluid that contains antimicrobial substances acting as the first-line of defense against pathogens, and its immune components may be potential tools for the discovery of new treatments against candidiasis. To evaluate the activity of histatin 5 and human lactoferrin against biofilm formation. A fluconazole-resistant Candida albicans clinical isolate was used as the model microorganism. Morphogenesis was evaluated by differential counting. Biofilm quantification was performed by XTT reduction assay. Thickness and topography of biofilms were assessed through confocal laser scanning microscopy (CLSM). Histatin 5 inhibited yeast-to-hyphae transition in a dose-dependent manner, while the effect of human lactoferrin on this process was inversely proportional to its concentration. Both compounds were able to significantly inhibit biofilm metabolic activity. Histatin 5 reduced biofilm thickness. Histatin 5 and human lactoferrin exhibited in vitro cytotoxicity against a fluconazole-resistant Candida albicans biofilm, which points to the potential application of these compounds in the treatment of biofilms formed by this fungus, especially in resistant infections.