Abstrato

Comparison of the Virulence of Different Candida albicans Samples Isolated from HIV-Positive Patients and Denture Stomatitis Lesions: In Vitro and In Vivo Tests

Fernanda Freire, Felipe de Camargo Ribeiro, Damara da Silva Ávila, Cristiane Aparecida Pereira, Juliana Campos Junqueira, Antonio Olavo Cardoso Jorge

The objective of this study was to evaluate the in vitro and in vivo virulence of candidiasis induced by Candida albicans. Four clinical samples, two from HIV-positive patients (14/60) and two from denture stomatitis (DS) lesions (32/62), and one reference strain were used in this study. Initially was evaluated the in vitro secretion of hemolysin, lipase, phospholipase and proteinase enzymes; and cell surface hydrophobicity. Following, mice were immunosuppressed and inoculated with C. albicans suspensions. After six days, the animals were euthanized and the tongues were removed for macroscopic and histological analysis. All samples produced the virulence factors; however the samples from HIV-positive patients were more virulent. In the macroscopic analysis, all groups showed candidiasis lesions, without significant difference between them. The group inoculated with isolates of C. albicans from HIV-positive patients had higher amount of yeasts and hyphae (p=0.0036), and more tissue damage (p=0.0016). The inflammatory infiltrate showed statistical difference between the strains 14 and 62, and also between samples 62 and 32 (p<0.0001). Based on these results it can be concluded that the clinical samples from HIVpositive patients were more virulent. The experimental model of this work was essential to increase our understanding of the pathogenicity of C. albicans.