Oral colonization by yeasts in HIV-positive patients in Brazil

Abstract

INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56%) followed by non-albicans Candida species (43.73%), Trichosporon mucoides (3.12%) and Kodamaea ohmeri (1.56%). Oral colonization by association of different species was observed in 42% of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

Comparison of the hemolytic activity between C. albicans and non-albicans Candida species

“…However, the epidemiology of yeast infection is rapidly evolving, and non-albicans Candida species have emerged as major opportunistic pathogens primarily in the specific conditions of immunodeficiency, such as acquired immunodeficiency syndrome. 12 The present results showed that most Candida species (92%) produced hemolysins; of these species, 58% had strongly positive hemolytic activity. These findings agree with those of Ramesh et al 17 who compared the hemolytic activity of 50 Candida strains isolated from patients with HIV and 10 Candida strains isolated from immunocompetent patients.…”

“…The strains were isolated and identified as previously described by Junqueira et al 12 The isolates tested included the following species:…”

Human Mycobiota-Selected Ontocenoses of Students of Natural Science and Medicine

“…The dominant species reported in previous studies of the mucous membrane was Candida albicans, isolated from 60-89% of subjects [17,18,[22][23][24]. Other species were recorded with significantly lower incidence: C. parapsilosis in 33% and C. tropicalis only in 13% of patients [2,3,20,21,[25][26][27].…”

Virulência de isolados clínicos de Candida tropicalis

“…O aumento da incidência das infecções fúngicas tem sido associada a pacientes com comprometimento do sistema imunológico 1,2,3 , Candida albicans é a espécie frequentemente isolada 4,5,2,3 . No entanto, outras espécies têm aumentado significativamente sua prevalência, dentre estas C. tropicalis 6,3,7 .…”