Biochemical analysis of the methylic antigen of Paracoccidioides brasiliensis

Yeast forms of five strains of Paracoccidioides brasiliensis (SN, 2, 18, 192 and JT- 1) were cultured in a synthetic medium for obtaining methylic antigens. These antigens were lyophilized and studied for each strain, to determine their partial biochemical composition, through measurements of total lipid, protein and carbohydrate contents. Lipids of methylic antigens were purified and analysed for sterols, phospholipids, glycolipids, li-poproteins, and partial characterization of sterols. Significant differences were found among antigenic preparations derived from distinct P. brasiliensis strains, in relation to the quantitative determinations. On the other hand, sterol analysis revealed the presence of ergosterol, lanosterol and squalene in all samples. The diversity verified in the biochemical characteristics of antigens derived from different P. brasiliensis strains, confirm the need of using a pool of fungal samples in order to produce antigen preparations for serological procedures without hampering their sensitivity

Análise bioquímica de antígeno metílico de Paracoccidioides brasiliensis

Cinco amostras de Paracoccidioides brasiliensis (SN, 2, 18, 192 e JT-1) em fase leveduriforme foram cultivadas em meio sintético para obtenção de antígenos metílicos. Os antígenos provenientes de cada amostra foram liofilizados e analisados quanto à sua composição bioquímica parcial, através da determinação do conteúdo total de lipídios, proteínas e carboidratos. Os lipídios dos antígenos metílicos foram purificados e analisados quanto ao teor de esterois, fosfolipídios, glicolipídios e lipoproteínas. Esterois foram parcialmente caracterizados. Em relação às medidas quantitativas, foram encontradas diferenças significantes entre as preparações antigênicas provenientes de amostras distintas de P. brasiliensis. Por outro lado, a análise dos esterois revelou a presença de ergosterol, lanosterol e esqualeno em todas as preparações. As diferenças verificadas nas características bioquímicas de antígenos derivados de amostras diferentes de P. brasiliensis confirmam a necessidade do uso de um pool de cepas para obtenção de preparações antigênicas a serem empregadas em procedimentos sorológicos, sem o que tais reações poderão ter sua sensibilidade comprometida.Yeast forms of five strains of Paracoccidioides brasiliensis (SN, 2, 18, 192 and JT- 1) were cultured in a synthetic medium for obtaining methylic antigens. These antigens were lyophilized and studied for each strain, to determine their partial biochemical composition, through measurements of total lipid, protein and carbohydrate contents. Lipids of methylic antigens were purified and analysed for sterols, phospholipids, glycolipids, li-poproteins, and partial characterization of sterols. Significant differences were found among antigenic preparations derived from distinct P. brasiliensis strains, in relation to the quantitative determinations. On the other hand, sterol analysis revealed the presence of ergosterol, lanosterol and squalene in all samples. The diversity verified in the biochemical characteristics of antigens derived from different P. brasiliensis strains, confirm the need of using a pool of fungal samples in order to produce antigen preparations for serological procedures without hampering their sensitivity

A case of mycotic keratitis caused by Fusarium solani

O caso estudado refere-se a paciente do sexo masculino, 36 anos, feoderma, sem história de doença sistêmica ou trauma ocular, apresentando úlcera corneana no olho esquerdo. Antes do estabelecimento do diagnóstico específico, o paciente foi tratado com antibiótico associado a corticosteróides durante um mês. O exame direto realizado a partir de raspado de córnea tratado com KOH revelou a presença de hifas fúngicas e clamidosporos, e o cultivo do material em ágar Sabouraud dextrose mostrou-se positivo para Fusarium solani. É enfatizada a necessidade do uso cauteloso de antibióticos e corticosteróides no tratamento de infecções da córnea, bem como de se considerar a possibilidade de etiologia fúngica destes quadros.A 36-year-old black man, without history of systemic disease or ocular trauma developed a corneal infection in his left eye. He was treated with antibacterial antibiotic and corticosteroids for one month prior to diagnosis. Fungal hyphae and chlamydospores were found in a KOH preparation of the corneal scrapings, and positive cultures for Fusarium solani were obtained in Sabouraud dextrose agar. It is emphasized the cautious use of antibiotics and steroids in corneal diseases, and the need of considering the involvement of opportunistic fungi in the etiology of these infections