[Characterization of Paracoccidioides brasiliensis antigens. Serological immunodiagnosis using western blotting]. / Caracterización de antígenos Paracoccidioides brasiliensis. Inmunodiagnóstico serológico mediante western blotting.

The electrophoretic characterization on SDS-PAGE gels of Paracoccidioides brasiliensis antigens, strains 2511 and 6688; and the additional use of immunoblotting has permitted in this study to identify the immunogenic, sensitive and specific antigen fractions for the diagnosis of Paracoccidioidomycosis. The antigenic preparations showed differences depending on the morphologic form of the fungus and the method utilized. The procedure revealed heterogeneity in the humoral immune response of the patients studied and permitted us to establish indices of activity of Paracoccidioidomycosis by the sequential analysis of sera obtained during different stages of the disease. The high sensitivity of this method makes it useful as an additional technique for the serologic immunodiagnosis of Paracoccidioidomycosis.

[Serotyping of 27 Cryptococcus neoformans strains isolated in Venezuela]. / Serotipificación de 27 cepas de Cryptococcus neoformans aisladas en Venezuela.

Twenty seven autochtonous isolates of Cryptococcus neoformans from different parts of the country were studied. The analysis indicated the following serotype distribution: 63% Serotype A, 29.6% Serotype B, 3.7% Serotype D and 3.7% belonging to C. neoformans var gattii.

Growth temperatures of isolates of Sporothrix schenckii from disseminated and fixed cutaneous lesions of sporotrichosis.

In 1979 Kwon Chung described two varieties of Sporothrix schenckii based on the thermotolerance of isolates from fixed cutaneous (35 degrees C) and that of disseminated cutaneous forms (37 degrees C) of sporotrichosis. Since we had not noted such a difference previously in a study of 100 cases of this disease (55% localized and 45% disseminated) wherein all the isolates grew at 37 degrees C, we decided to repeat this work. Our results differ from those reported by Kwon Chung, since the isolates of both the fixed and disseminated forms of sporotrichosis grew at 37 and 38 degrees C, even when we used inocula of 30 conidia (20-50) which according to Kwon Chung were needed to observe this difference.

Application of immunoprecipitation techniques to the diagnosis of cutaneous and extracutaneous forms of sporotrichosis.

Sporotrichosis is a mycosis which in our country has been described as only producing cutaneous and subcutaneous infections; in other countries it has been reported as causing pulmonary, bone, joint and meningeal infections. Possibly the systemic form also occurs in Venezuela since, along with the causative agent, all other factors considered as predisposing to systemic infection exist here. Through immunodiffusion (ID) and immunoelectrophoresis (IEP) and using a filamentous form metabolic antigen from Sporothrix schenckii, we were able to demonstrate precipitating antibodies against this fungus both in patients with cutaneous sporotrichosis, diagnosed by culture of the infecting agent, and in patients with pulmonary lesions. The IEP test showed the presence of an anodic arc which we have called the 'S' arc, which could be one of the specific antigens of S. schenckii.

Specific double diffusion microtechnique for the diagnosis of aspergillosis and paracoccidioidomycosis using monospecific antisera.

Using experimental reference sera against species-specific antigens of Aspergillus fumigatus and Paracoccidioides brasiliensis in a microdouble diffusion technique, a simple and specific test for the immunodiagnosis of aspergillosis and paracoccidioidomycosis has been developed. Only sera that produced lines of identity with either one of the bands formed by the anti-C2 or the anti-E2 reference sera were considered positive for aspergillosis or paracoccidioidomycosis, respectively. The sensitivity of the diagnostic test was similar to those of the classical double diffusion and the immunoelectrophoresis test. No false positives were found in sera obtained from patients affected by other mycoses, nor from healthy controls. The amount of reagents for the specific test was ten fold less than that required by the classical double diffusion test.

[Foot mycetoma of double etiology]. / Micetomas de localizacion podal de etiologia doble.

A patient coming from an area of dry tropical forest was studied. This patient had in his right foot two tumor-like growths localized, one in the anterior and superior part of the foot, the other near the malleoli. From the first tumor, light-colored grains were obtained, and Actinomadura madurae was cultured. From the tumor near the malleoli only black grains were isolated from which a Pyrenochaeta sp. was cultured.

[Onychomyosis caused by Trichopyton soudanense. 1st isolation in Venezuela]. / Onicomicosis por Trichopyton soudanense. Primer Aislamiento en Venezuela

Trichophyton soudanense is a dermatophyte wich is of highest incidence in Africa. Cases of tinea produced by this fungus have been described in England, Switzerland, Germany, Australia, the United States and Brazil. This investigation reports the first isolation of this fungus in Venezuela, from a lesion of the nail in a female patient who has always resided in Venezuela. The identification of this fungus was based on macroscopic and microscopic morphological characteristics; biological properties, scare or no growth when the only nitrogen source in the culture medium is provided by potassium or ammonium nitrate, and the production of dark pigment when inoculated in Lowenstein-Jensen medium. Experimental innoculation in animals produced an endothrix parasitism of the hair. Reference is made ot the incidence of the most frequently occuring dermatophytes in Venezuela.