Tipagem molecular e suscetibilidade antifúngica de Cryptococcus isolados de pacientes em hospital universitário com investigação domiciliar

Abstract

Cryptococcosis, an infection of systemic features, is caused by Cryptococcus neoformans and Cryptococcus gattii. It affects both normal and immunocompromised patients and has been associated with high mortality. The purpose of this study was to identify the species and molecular types of Cryptococcus isolates from diagnosed cases, determine their susceptibility to antifungal agents used in clinical practice, and investigate the presence of these agents in the households of patients treated for cryptococcosis at the Hospital Universitário de Mato Grosso do Sul from February 2009 to July 2010. Clinical and environmental samples were identified using standard phenotypic tests. Susceptibility to antifungal agents (fluconazole, itraconazole, voriconazole, and amphotericin B) was determined using the Clinical Laboratory Standards Institute (M27-A3) broth microdilution method. Molecular typing was based on the restriction fragment polymorphisms – URA5 method. Fifteen patients were diagnosed with cryptococcosis during the period of study. Meningoencephalitis (46.7%) and disseminated infection (26.7%) were the most frequently observed clinical syndromes. Of the patients investigated, 60.0% were HIV-infected. Overall mortality was 46.7%. Among HIV-positive patients, the death rate was 44.5% whereas no deaths among HIV-negative individuals. Molecular typing of yeasts isolated from clinical samples revealed 73.3% to be C. neoformans (VNI) and 26.7% C. gattii (VGII). Cryptococcus neoformans had the same molecular type as the clinical specimen (VNI) in only one of the six residences visited. Cryptococcus neoformans and C. gattii were sensitive to all antifungal agents tested. The presence of Cryptococcus neoformans in household dust suggests domestic infection, underscoring the importance of investigating the ecoepidemiology of this disease. This was the first study on the molecular characterization and antifungal susceptibility of Cryptococcus sp. conducted in Mato Grosso do Sul state and the first to include molecular typing of Cryptococcus sp. isolated from the domestic environment of patients with cryptococcosis.