Caracterização e identificação de fungos causadores de infecções nosocomiais em pacientes transplantados de células tronco hematopoiéticas

• Autor(a) principal: Camplesi Junior, Milton
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3508
• topic: Aspergillus sp; Pacientes transplantados de células tronco hematopoiéticas; Galactomanana; Aspergillus sp; Patients hematopoietic stem cell transplantation; Galactomannan; MICROBIOLOGIA APLICADA::MICROBIOLOGIA MEDICA

Invasive fungal infections have emerged in the last two decades as a major cause of nosocomial fungal infections, with emphasis on those caused by Candida species and Aspergillus. Invasive aspergillosis (IA) has a high mortality rate and early detection of Aspergillus is of paramount importance for the treatment and consequently prevention of patient death. The galactomannan (GM) cell wall protein component of Aspergillus species can be detected in serum, urine, cerebrospinal fluid and bronchoalveolar lavage. The detection of GM in the early stages of the disease is considered a useful marker for early diagnosis of the disease. The aim of this study was to determine the incidence of fungal infections in patients transplanted hematopoietic stem cells. In this study was verified the incidence of fungal infections in 117 patients undergoing hematopoietic stem cell transplantation (HSCT), whose data such as age, gender and underlying disease were cataloged. Blood samples of these 392 patients were collected, and tested for detection of GM using ELISA (Enzyme-Linked Immunosorbent Assay) test and cultivated in culture medium containing biphasic brain heart infusion (broth) and Sabouraud dextrose (agar) for isolation of fungal. The fungi isolated were subjected to in vitro susceptibility testing using broth microdilution method for the antifungal agents: itraconazole, voriconazole, fluconazole, caspofungin and amphotericin B. Among the data obtained from HSCT patient it has been found that the mean age was 35,7 years and the largest number belonged to the age group between 21 and 60 years; 52,2% were male, 53% had received allogeneic stem cell transplant. Leukemias (55,5%) were the main diseases responsible for transplant. Fungal isolates from clinical samples were identified as A. fumigatus (02), Aspergillus flavus (01), Fusarium sp (01), Acremonium strictum (01), Candida parapsilosis (06), Candida tropicalis (06) and Candida albicans (04). Of all patients analyzed 19,6% (23/117) had two or more positive samples for GM. According to European Organization for Research and Treatment of Cancer, invasive aspergillosis was interpreted as proven in 2,5% defined by growth of Aspergillus in culture, 5,9% as probable for the detection of GM in blood and pulmonary infiltrates and 2,5% as possible by radiological changes suggestive of aspergillosis and negative GM. The mortality rate for AI proven/probable was 60% and showed that the disease was significantly associated with the risk of death (P <0,05). The filamentous fungi were more susceptible in vitro to voriconazole, while higher susceptibility of the yeast was found to Caspofungin. Considering that the crude mortality rate of IA is very high and the early therapy may lead to improved prognosis, we could suggest that the Platelia Aspergillus GM EIA in serum of patients could be useful as screening tools for identification in patients at high risk of developing IA.