RESUMO
Surgical specimens were obtained from a patient who had had life-threatening paracoccidioidomycosis 5 years previously. Residual lesions were found in the mesenteric lymph nodes; there were areas of caseous necrosis separated from the surrounding tissue by a fibrous capsule made of connective tissue. Abundant P. brasiliensis cells, many of which appeared degenerated, were observed in the necrotic material. Primary isolation was possible only under the microaerophilic conditions offered by fluid media kept stationary at 36 degrees C. Cultures in solid media were obtained after serial passages and gradual accommodation of the strain to aerobic incubation. It is apparent that P. brasiliensis yeast cells can become accustomed to reduced oxygen tension in the tissues. In this way, they are able to withstand the passing of time without completely losing their viability.
Assuntos
Calcinose/microbiologia , Fungos/isolamento & purificação , Linfonodos/microbiologia , Técnicas Microbiológicas , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/microbiologia , Adolescente , Adulto , Meios de Cultura , Humanos , Masculino , Oxigênio/metabolismo , Paracoccidioides/metabolismoRESUMO
A total of 60 clinical isolates of Paracoccidioides brasiliensis were tested for susceptibility to sulfadiazine and sulfadimethoxyne by the agar dilution technique. A modification of the Mueller-Hinton medium was devised which gave good growth of the yeast form. The minimum inhibitory concentrations for only 51.6% of the isolates were in the range of the recommended blood serum concentration (50 micrograms/ml). For 6 to 8% of the isolates, the minimum inhibitory concentrations were above 200 micrograms of both sulfadiazine and sulfadimethoxyne per ml. A significant decreases in susceptibility was demonstrated for one isolate obtained from a patient relapsing during sulfonamide therapy.