Comparative electrophoresis, isoelectric focusing and numerical taxonomy of some isolates of Fonsecaea pedrosoi and allied fungi

Heterogeneity of proteins expressed by Brazilian Sporothrix schenckii isolates

The profiles of proteins present in the exoantigens of Brazilian Sporothrix schenckii isolates were studied and compared by electrophoresis (SDS-PAGE). Thirteen isolates from five different regions of Brazil (1,000 to 2,000 km apart) and ten from a more limited region (200 to 400 km apart within the state of São Paulo) were cultured in Sabouraud, M199 and minimum (MM) media. Qualitative and quantitative differences in the expression of proteins, which varied according to the medium and the isolate, were observed. Fractions with the same MW but varying in intensity were detected, as well as fractions present in 1 isolate but absent in others. Dendrograms were constructed and isolates grouped based on the fractions obtained, irrespective of the intensity. The results showed that Brazilian S. schenckii isolates express different protein profiles, a feature also present in isolates from a more restricted region. The exoantigens were found to have a maximum of 15 protein fractions, ranging in MW from 19-220 KDaltons depending on the medium used for the cultures. These data show the great heterogeneity of Brazilian S. schenckii protein expression.

Development of natural culture media for rapid induction of Fonsecaea pedrosoi sclerotic cells in vitro

Fonsecaea pedrosoi is the main agent of chromoblastomycosis, a skin disease presenting verrucous lesions, in which round, thick-walled sclerotic cells are found. In vitro induction of sclerotic cells is time-consuming (20 to 45 days) and temperature dependent. We present two new natural media that reduce the sclerotic-cell induction time to only 2 days.

Immunoprecipitation techniques and Elisa in the detection of anti-Fonsecaea pedrosoi antibodies in chromoblastomycosis

Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by several dematiaceous fungi. The most commonly etiological agent found in Brazil is Fonsecaea pedrosoi, which appears as thick walled, brownish colored cells with transverse and longitudinal division in the lesions, called "muriform cells". This disease is found worldwide but countries like Madagascar and Brazil have highest incidence. Diagnosis is made by clinical, direct and histopathologic examination and culture of specimens. Serological tests have been used to identify specific antibodies against Fonsecaea pedrosoi antigens, as well as immunotechniques have been used for CBM serological identification and diagnosis. In the present study double immunodiffusion (DID), counterimmunoelectrophoresis (CIE) and immunoenzymatic test (ELISA) have been used to evaluate humoral immune response in patients with CBM caused by F. pedrosoi. Metabolic antigen was used for immunoprecipitation tests (DID and CIE) while somatic antigen for ELISA. Our results demonstrated 53% sensitivity and 96% specificity for DID, while CIE presented 68% sensitivity and 90.5% specificity. ELISA demonstrated 78% sensibility and 83% specificity. Serological tests can be a useful tool to study different aspects of CBM, such as helping differential diagnosis, when culture of the pathogenic agent is impossible.

The antigenic composition and protein profiles of eumycetoma agents

The protein profiles of different eumycetoma agents were compared by SDS gel electrophoresis. Dendrograms confirmed the homogeneity of isolates of Pseudallescheria boydii but amongst Madurella species, particularly isolates identified as M. grisea, there were substantial differences in protein composition. However using Western blotting reference isolates of the different species showed distinct antigen patterns in response to immune rabbit sera. In particular there was little evidence of cross reactivity between M. mycetomatis and M. grisea. However this specificity was not apparent when human sera from patients with different eumycetoma infections were compared in an ELISA system using the same antigens. It is possible that the formation of a mycetoma grain may limit a patient's exposure to antigens which confer specificity, an explanation which may also account for the variability in antibody responses seen.

Electrophoretic protein patterns of Geotrichum and its teleomorphs

Total patterns of water-soluble proteins of 35 strains (7 species) of Galactomyces and Dipodascus strains with their respective Geotrichum anamorphs are compared. Quantitative differences among a number of species are found with iso-electric focusing; bands that characterize species are selected. Qualitative differences are found between the teleomorph genera.

An extended QBASIC program for the normalization and computation of whole-cell protein profiles and the application to clinically important Candida species

The computer program described enables a rapid calculation of relative molecular masses of proteins from different yeasts and microbial pathogens, by interpolation from a molecular weight calibration curve that comprises stepwise linear regression between the protein bands produced by the internal standards. A similarity matrix can then be produced, taking into account variations between calculated molecular masses caused by small differences in bandwidths and/or positions of specific protein bands. This program has been applied to different Candida species and the similarity data obtained further analysed numerically utilizing CLUSTAN II on a SPERRY 1100 multi-processor.

Isoelectric focusing applied to taxonomic differentiation of the Trichophyton mentagrophytes complex and the related Trichophyton interdigitale

Somatic extracts from dermatophytes of the Trichophyton mentagrophytes complex and of Trichophyton interdigitale grown on trypticase soy broth were prepared for analytical isoelectric focusing in thin layer polyacrylamide gels over the pH range 4-6.5. A total of 44 strains were studied: 8 Arthroderma benhamiae (4 Americano-European and 4 African races), 4 Arthroderma vanbreuseghemii, 6 Trichophyton mentagrophytes and 26 Trichophyton interdigitale. Laser densitometric analysis revealed two outstanding clusters of profiles. The first one matched with the Arthroderma vanbreuseghemii profile and gathered all the Trichophyton interdigitale strains studied and 4 Trichophyton mentagrophytes. The second one corresponded to the Arthroderma benhamiae profile and gathered 2 Trichophyton mentagrophytes. This isoelectric focusing analysis suggests on one hand that Trichophyton interdigitale might be the anamorph species corresponding to the teleomorph Arthroderma vanbreuseghemii, and on the other hand that Trichophyton mentagrophytes might correspond to two teleomorph species, either Arthroderma vanbreuseghemii or Arthroderma benhamiae.