No abstract

Sporotrichosis is a polymorphic disease caused by a complex of thermodimorphic fungi including S. brasiliensis, S. schenckii sensu stricto (s. str.), S. globosa and S. luriei. Humans and animals can acquire the disease through traumatic inoculation of propagules into the subcutaneous tissue. Despite the importance of sporotrichosis as a disease that can take epidemic proportions there are just a few studies dealing with genetic polymorphisms and genomic architecture of these pathogens. The main objective of this study was to investigate chromosomal polymorphisms and genomic organization among different isolates in the S. schenckii complex. We used pulsed field gel electrophoresis (PFGE) to separate chromosomal fragments of isolated DNA, followed by probe hybridization. Nine loci (β-tubulin, calmodulin, catalase, chitin synthase 1, Internal Transcribed Spacer, Pho85 cyclin-dependent kinase, protein kinase C Ss-2, G protein α subunit and topoisomerase II) were mapped onto chromosomal bands of Brazilian isolates of S. schenckii s. str. and S. brasiliensis. Our results revealed the presence of intra and interspecies polymorphisms in chromosome number and size. The gene hybridization analysis showed that closely related species in phylogenetic analysis had similar genetic organizations, mostly due to identification of synteny groups in chromosomal bands of similar sizes. Our results bring new insights into the genetic diversity and genome organization among pathogenic species in the Sporothrix schenckii complex.

We used RAPD (random amplification of polymorphic DNA) to analyze the phenotypic and genotypic characteristics of Sporothrix schenckii isolated from five geographic regions of Brazil, from clinical, animal, and environmental sources. Our results yielded a significant difference (P<0.01) in the mean conidial area of S. schenckii animal isolates (2.96 ± 1.07) compared with those of clinical isolates (fixed form, 2.33 ± 0.53; lymphocutaneous form, 2.37 ± 0.43). There was no association among S. schenckii clinical isolates and geographic region. Isolates from the Northeast region exhibited the lowest thermotolerance (% growth inhibition) at 35ºC (x = 49.23% ± 17.25) and at 37ºC (70.43% ± 10.93%). Northern isolates exhibited the highest thermotolerance at 35ºC (12.82% ± 5.73%) and at 37ºC (23.81% ± 8.27%). RAPD with a 10-mer primer OPD-18 generated 67 PCR fingerprint patterns. The 151 S. schenckii isolates fell into seven major clusters with such great genetic diversity that an association of isolates with clinical forms or geographic areas could not be determined, even with investigations focused on more restricted geographic areas. The main physiological characteristics of Brazilian S. schenckii isolates were also characterized, including osmophilia, halophilia, pH tolerance, urease activity, casein hydrolysis, and gelatinase, proteinase, and DNAase production.

Introduction: Paracoccidioidomycosis is a systemic infection caused by Paracoccidioides brasiliensis. Methods: In this study, a semi-nested PCR for paracoccidioidomycosis diagnosis was developed. The primers ITS1 and ITS4 were used in the first reaction, while the primers MJ03 and ITS1 primer were used in the second reaction. The semi-nested PCR was used to investigate biopsies of five patients with oral lesions that resembled paracoccidioidomycosis. Results: The semi-nested PCR was positive for four samples and negative for a sample from a patient later diagnosed with leishmaniasis. Conclusions: The new semi-nested PCR describe is useful for paracoccidioidomycosis diagnosis.

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.