Antimicrobial effect of farnesol, a Candida albicans quorum sensing molecule, on Paracoccidioides brasiliensis growth and morphogenesis

Abstract

BackgroundFarnesol is a sesquiterpene alcohol produced by many organisms, and also found in several essential oils. Its role as a quorum sensing molecule and as a virulence factor of Candida albicans has been well described. Studies revealed that farnesol affect the growth of a number of bacteria and fungi, pointing to a potential role as an antimicrobial agent.MethodsGrowth assays of Paracoccidioides brasiliensis cells incubated in the presence of different concentrations of farnesol were performed by measuring the optical density of the cultures. The viability of fungal cells was determined by MTT assay and by counting the colony forming units, after each farnesol treatment. The effects of farnesol on P. brasiliensis dimorphism were also evaluated by optical microscopy. The ultrastructural morphology of farnesol-treated P. brasiliensis yeast cells was evaluated by transmission and scanning electron microscopy.ResultsIn this study, the effects of farnesol on Paracoccidioides brasiliensis growth and dimorphism were described. Concentrations of this isoprenoid ranging from 25 to 300 μM strongly inhibited P. brasiliensis growth. We have estimated that the MIC of farnesol for P. brasiliensis is 25 μM, while the MLC is around 30 μM. When employing levels which don't compromise cell viability (5 to 15 μM), it was shown that farnesol also affected the morphogenesis of this fungus. We observed about 60% of inhibition in hyphal development following P. brasiliensis yeast cells treatment with 15 μM of farnesol for 48 h. At these farnesol concentrations we also observed a significant hyphal shortening. Electron microscopy experiments showed that, despite of a remaining intact cell wall, P. brasiliensis cells treated with farnesol concentrations above 25 μM exhibited a fully cytoplasmic degeneration.ConclusionOur data indicate that farnesol acts as a potent antimicrobial agent against P. brasiliensis. The fungicide activity of farnesol against this pathogen is probably associated to cytoplasmic degeneration. In concentrations that do not affect fungal viability, farnesol retards the germ-tube formation of P. brasiliensis, suggesting that the morphogenesis of this fungal is controlled by environmental conditions.

Effect of Farnesol on Growth, Ergosterol Biosynthesis, and Cell Permeability in Coccidioides posadasii

“…More recently, many studies have described the activity of farnesol against different species of fungi (15)(16)(17)(18). In this study, for the first time, the antifungal activity of farnesol against the primary pathogen C. posadasii, the causative agent of coccidioidomycosis, was investigated.…”

“…Some studies have confirmed the inhibitory effect of farnesol on the growth of microorganisms (12)(13)(14)(15)(16). It was shown that farnesol can act as an antifungal agent against the dimorphic fungus Paracoccidioides brasiliensis (16).…”

“…It was shown that farnesol can act as an antifungal agent against the dimorphic fungus Paracoccidioides brasiliensis (16). More recently, our group demonstrated its inhibitory activity against Cryptococcus spp.…”

Nutriceutical potential of Pleurotus tuber-regium sclerotium

“…It action as pheromone for most insects, and as a natural pesticide for termites [25], shows its role in the protection of this mushroom from termites and other insects. The use of Farnesol to emphasize the aroma of perfumes is based on its activity as a co-solvent that regulates the volatility of the component aromas of perfumes, [17], while its antibacterial property makes it a potential deodorant in cosmetic products [26]. Farnesol and its derivatives has been reported as important starter in the synthesis of both natural and artificial organic compounds [27].…”

Gas Chromathography as a Tool in Quorum Sensing Studies

“…The fungicide activity of farnesol on this pathogen is probably associated to cytoplasmic degeneration, in spite of the apparent cell wall integrity, as observed by transmission and scanning electron micrographs. In concentrations that did not affect fungal viability, farnesol retards the germ-tube formation of P. brasiliensis, suggesting that the morphogenesis of this fungal is controlled by environmental conditions (Derengowski et al, 2009). …”