Virulence factors of Candida species isolated from invasive and non invasive infections: Biofilm formation and cell surface hydrophobicity.

RODRIGUEZ, EMILSE; ICELY, PAULA ALEJANDRA; MIRÓ, MARÍA SOLEDAD; CASTILLO, GRACIELA; AZCURRA, ANA ISABEL; VIGEZZI, CECILIA; VARGAS, LARA; ABIEGA, CLAUDIO; RIERA, FERNANDO; CAEIRO, JUAN PABLO; SOTOMAYOR, CLAUDIA ELENA

Santiago de Chile

Congreso; XIV Forum on Fungal Infection in the Clinical Practice; 2016

Introduction: Candida spp. have emerged as successful pathogens in both invasive and mucosal fungal infections in humans. Estimates suggest that Candida spp. are one of the most frequent nosocomial pathogens associated with bloodstream infections. Among non invasive infections, vulvovaginal candidiasis (VVC) affects approximately 75% of women with at least one episode during their lifetime and it is estimated than 5-8% of this patients develop the recurrent form of mycosis (RVVC).The success of Candida as both commensal and human pathogen depends on differents virulence determinants which facilitates adaptation to a wide range of host niches. A major virulence attribute of Candida spp. is its ability to form biofilms, community of surface-attached cells embedded in a self-produced extracellular matrix. Recently, significant correlations between biofilm formation (BF) and cell surface hydrophobicity (CSH) have been reported. This property is involved in the process of cell aggregation and adhesion that facilitates biofilm development. Biofilms are intrinsically resistant to conventional antifungal therapeutics, the host immune system, and other environmental factors, making biofilm-associated infections a significant clinical challenge.Objective:The aim of this study was to evaluate virulence factors such as biofilm formation and cell surface hydrophobicity of Candida spp. clinical isolates from patients with invasive and non invasive infections, and compare the virulence pattern exhibited by the fungus in different human reservoirs.Materials and methods:The present study was carried out on 27 clinical isolates of Candida spp. obtained from patients with bloodstream infection and 29 isolates from vaginal infections. Patients with VVC were divided in two groups: 6 acute VVC (AVVC) patients, who had only one symptomatic episode and 23 RVVC, who had four or more symptomatic episodes per year. Species identification of these isolates was performed by MALDI-TOF (Biomerieux) and molecular methods. Quantitative measurement of biofilm formation was assessed by XTT reduction assay performed in triplicate for all strains and the averages and standard deviations were calculated for all experiments. Strains was classified as Weak (Absorbance(A)<0.310)(WBF), Moderate (0.310