Isolation of fungi from nature in the region of Botucatu, State of Sao Paulo, Brazil, an endemic area of Paracoccidioidomycosis

In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplement with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25º and 37ºC. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P.brasiliensis. In addition, 98 dematiaceous fungi and 581 different soecies of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.

Fibrosis patterns of lesions developed by athymic and euthymic mice infected with Paracoccidioides brasiliensis

Athymic and euthymic mice with BALB/c background were used to study the patterns of fibrosis during ip infection with a virulent isolate of Paracoccidioides brasiliensis. Specimens from various organs were collected from the animals at 1,4 and 7 weeks after infection and observed under light microscopy using various histologic staining methods. Lesions from the first week of infection, in both animal groups, presented a predominance of collagen III over I, carboxylated proteoglycans, and a tendency to encapsulation. From 4 weeks onward, the lesions of nu/+mice tended to involute to macrophage-pseudoxanthomatous aggregates or to encapsulation with an increase of collagen I and sulfated proteoglycans. On the contrary, with the evolution of the infection, the nu/nu mice displayed permanently active lesions, rich in reticular fibers and carboxylated proteoglycans, with varied amounts of collagens III and I, without or with minimal encapsulation. However, independent of the type of mice, or of the type of lesions, the minimal P. brasiliensis-ECM unit was formed by a fibrillar cocoon of reticular fibers that encloses an individual yeast or a "family" composed of a mother cell plus one or various peripheral daughter cells, alone or engulfed by macrophages or giant cells. The overal difference of the lesions of nude and normal mice was not in isolated aspects of their components, but in the general architecture of the lesions. Those of nu/+mice were either of involutive or of encapsulated type (slightly active), and those of nu/nu mice were of the sustained-expansive type (very active), without or with minimal encapsulation

Experimental paracoccidioidomycosis in hamster: transmission electron microscopy of inoculation site lesion

Estudou-se sequencialmente, a microscopia eletronica de transmissao, a interacao entre Paracoccidioides brasiliensis (Pb) e celulas inflamatorias em hamsters inoculados por via intratesticular. Seis horas apos inoculacoes havia predominancia de neutrofilos, estando presentes algumas celulas mononucleares e eosinofilos. Os neutrofilos foram progressivamente substituidos por celulas mononucleares. Fungos viaveis apresentavam-se fagocitados ou circunscritos por celulas inflamatorias, geralmente com ampla interface hospedeiro-parasita. Fungos mortos ou degenerados eram acompanhados de interfase estreita. A camada externa da parede do Pb era as vezes quebrada quando em contato com neutrofilos, em varios pontos, sendo os fragmentos dessa parede descamados e fagocitados....