Influence of Eugenia uniflora Extract on Adhesion to Human Buccal Epithelial Cells, Biofilm Formation, and Cell Surface Hydrophobicity of Candida spp. from the Oral Cavity of Kidney Transplant Recipients.

Luanda Souza,Maria Mendes-Giannini,Ana Fusco Almeida,Guilherme Maranhão Chaves,Luiz Soares,Eveline Milan,Terezinha Svidzinski,Magda Ferreira,Regina Pires,Walicyranison Silva-Rocha

doi:10.3390/molecules23102418

Abstract

This study evaluated the influence of the extract of Eugenia uniflora in adhesion to human buccal epithelial cells (HBEC) biofilm formation and cell surface hydrophobicity (CSH) of Candida spp. isolated from the oral cavity of kidney transplant patients. To evaluate virulence attributes in vitro, nine yeasts were grown in the presence and absence of 1000 μg/mL of the extract. Adhesion was quantified using the number of Candida cells adhered to 150 HBEC determined by optical microscope. Biofilm formation was evaluated using two methodologies: XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and crystal violet assay, and further analyzed by electronic scan microscopy. CSH was quantified with the microbial adhesion to hydrocarbons test. We could detect that the extract of E. uniflora was able to reduce adhesion to HBEC and CSH for both Candida albicans and non-Candida albicans Candida species. We also observed a statistically significant reduced ability to form biofilms in biofilm-producing strains using both methods of quantification. However, two highly biofilm-producing strains of Candida tropicalis had a very large reduction in biofilm formation. This study reinforces the idea that besides growth inhibition, E. uniflora may interfere with the expression of some virulence factors of Candida spp. and may be possibly applied in the future as a novel antifungal agent.

Highlights

Candida species are micro-organisms of medical interest due to the high frequency with which they colonize and infect the human host
This study aimed to evaluate the influence of the E. uniflora extract on the expression of some virulence factors in vitro of Candida species
If we consider that we have tested a higher number of strains than several other studies, this study study showed that the extract of leaves of E. uniflora acted in an efficient way in reducing adhesion showed that the extract of leaves of E. uniflora acted in an efficient way in reducing adhesion to human buccal epithelial cells (HBEC), to HBEC, cell surface hydrophobicity (CSH) and reducing biofilm formation

Summary

Introduction

Candida species are micro-organisms of medical interest due to the high frequency with which they colonize and infect the human host. Candida spp. figure as colonizing yeasts of the oral mucosa in about 20–80% of healthy adults without evidence of infection [1]. Depending on the immune status of the host and virulence attributes of Candida spp., these micro-organisms may become pathogenic, within particular groups of patients, such as transplant recipients, AIDS patients, and those under treatment with broad-spectrum antibiotics [2,3]. Oral candidiasis is a common opportunistic infection in kidney transplant recipients maintained under immunosuppressive therapy. It is important to emphasize that a study performed by our group revealed a statistically significant relationship between oral candidiasis and the use of dental prosthesis in renal transplant patients [2]

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