Avaliação da suscetibilidade in vitro de Fonsecaea spp a diferentes antifúngicos e análise das concentrações plasmáticas de itraconazol e hidroxiitraconazol em pacientes com cromoblastomicose na região amazônica

Chromoblastomycosis (CBM) is a fungal infection by implantation in the skin, with a chronic evolution, caused by traumatic inoculation of dematiaceous fungi. Pará state is one of the most important endemic areas in Brazil, and F. pedrosoi is the most prevalent agent. The low cure rate is consequence of the lack of a standardized treatment regimen and there are a few works related to susceptibility of black fungi to the drugs available for treatment. The main objective of this study was to evaluate in vitro susceptibility of clinical isolates of Fonsecaea spp. against nine antifungals, correlating itraconazole (ITZ) minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) with clinical outcome and the types of lesions. Furthermore, plasma levels of ITZ and ITZOH were measured in patients treated in Dr Marcello Candia Reference Unit in Sanitary Dermatology (UREMC, Pará State). Thirty-eight clinical isolates of Fonsecaea spp. were evaluated against ITZ, ketoconazole (CTZ), posaconazole (PCZ), voriconazole (VCZ), fluconazole (FCZ), amphotericin B (ANF B), caspofungin (CAS), terbinafine (TBF) and 5-fluorocytosine (5-FLU), according to the protocol of the Clinical and Laboratory Standards Institute (CLSI, M38-A2 document). After 5 days of incubation at 30°C, MICs were determined visually evaluating fungal growth in different drug concentrations, in comparison to the drug-free control wells. PCZ was the most effective (MIC 0.28 μg/ml, MFC 4.35 μg/ml) drug. The correlation between the MIC to ITZ and clinical outcome results demonstrate that patients with worsening had a media value ± SEM (0.90 ± 0.10 μg/ml) superior to no improvement (0.45 ± 0.05 μg/ml) or improvement (0.59 ± 0.05 μg/ml) and cure (0.45 ± 0.05 μg/ml), with a significant difference (p 1000 ng/ml na somatória ITZ+ITZOH, considerada satisfatória para a maioria das infecções fúngicas, além de apresentarem melhora do quadro clínico. Em resumo, nossos dados 1) confirmam F. pedrosoi como o principal agente etiológico da CBM no Pará; 2) não evidenciam correlação entre as lesões, as espécies e a sensibilidade ao ITZ; 3) demonstram que ITZ, VCZ e PCZ foram os fármacos com menor CIM, sendo que o PCZ apresentou a menor CFM; 4) correlacionam o metabólito ITZOH com a evolução clínica dos pacientes e; 5) indicam que o uso de altas doses de até 600 mg/dia de ITZ podem ser usadas em pacientes que não respondem a doses terapêuticas menores