Perfil antifúngico e antibiofilme de Lactobacillus casei sobre Candida spp.

Abstract

Species of the genus Candida have shown several factors associated with virulence, among these, the ability to form monospecies and multispecies fungal biofilms, as well as inter-kingdom biofilms such as the biofilms formed by Candida spp. and bacteria. Lactobacillus spp. are bacterial species that are part of the human microbiome and there are species that have probiotic function. Lactobacillus species have already been identified as promising agents for the treatment and/or prevention of Candida spp. In this sense, we aimed in our research, the identification of interference, positive or negative, of L. casei on the development of planktonic cells and Candida spp. biofilms. Mixed inter-kingdom biofilms were formed and fungal sensitivity, metabolic activity and biomass have been verified. An increase in the biomass content was observed in the presence of mixed biofilms when compared to the monospecies biofilm of Candida spp.. L. casei, in planktonic state, from the concentration of 5x10 6 cells mL -1 was able to reduce by 61% the metabolic activity of C. albicans planktonic cells when added at the time of incubation and during the exponential phase of C. albicans. L. casei, in planktonic state, was able to decrease by 36% the metabolic activity of planktonic cells of C. krusei from the concentration of 5x10 5 cells mL -1 . Addition of L. casei planktonic cells to the C. albicans biofilm in the maturation phase and to the C. krusei biofilm at the time of adhesion, from the concentration of 5x10 7 cells mL -1 , reduced the metabolic activity of Candida spp. Preformed biofilm of L. casei was able to decrease the metabolic activity of C. albicans and C. krusei biofilm by 16% and 21% respectively. Furthermore, L. casei biofilm reduced by 24% the metabolic activity of C. albicans biofilm. Finally, the antifungal fluconazole showed greater antibiofilm potential against Candida spp. when in interaction with L. casei. These results demonstrate the possibilities of interactions between fungal and bacterial species, often simulating the interactions that occur in the context of the human microbiome. These results are highly promising, especially with regard to the prophylaxis and treatment of infections associated with Candida spp.