A case of extensive chromoblastomycosis from North India

A case of extensive chromoblastomycosis of the right leg and thigh with verruciform to nodular lesions evolving rapidly over five years duration is reported. The diagnosis was confirmed by visualizing pathognomonic pigmented muriform bodies with unique septate hyphae and mycological culture yielding Fonsecaea pedrosoi.(AU)

Bacillus subtilis induces morphological changes in Fonsecaea pedrosoi in vitro resulting in more resistant fungal forms in vivo

Interactions among microorganisms may be the cause of morphological modifications, particularly in fungal cells. The aim of this work was to examine the changes that occur in cells of the fungus Fonsecaea pedrosoi after in vitro co-culturing with Bacillus subtilis and to explore the results of this interaction in vivo in an experimental murine infection. B. subtilis strain was inoculated into a 15-day pure culture of F. pedrosoi. In vitro, after 48 hours of co-culturing, the fungal cells were roundish. The secretion of fungal dark pigments and production of terminal chlamydoconidia were observed in hyphae after one week. In the in vivo study, two animal groups of 30 BALB/c mice each were employed. One group was inoculated intraperitoneally with hyphal fragments from the co-culture of bacteria and fungi; the other group was infected only with F. pedrosoi hyphae. After seven days of infection, both animal groups developed neutrophilic abscesses. Phagocytosis of bacilli by macrophages occurred at three days. At later periods, generally after 25 days, only roundish cells similar to sclerotic bodies remained in the tissues while hyphae were eliminated by 15 to 20 days. These fungal forms originated mainly from terminal chlamydoconidia. The co-culturing between bacteria and fungi may constitute a mechanism to rapidly obtain resistant fungal forms for host defenses, especially for chromoblastomycosis (CBM) experimental infections.(AU)

Experimental murine chromoblastomycosis obtained from Fonsecaea pedrosoi isolate cultured for a long periodt

The present study aimed to describe F. pedrosoi propagules capable of causing chronic murine disease. Several changes in F. pedrosoi hyphae were identified in fungal cells cultured for a long period. Optical microscopy found many rounded cells with double-rigid melanin-rich walls. Terminal and intercalary chlamydoconidia were also frequently observed. Analyses of images from transmission electron microscopy (TEM) revealed several cells with walls composed of at least three layers and an outer layer enriched with melanin. Two groups of twenty BALB/c mice were subcutaneously infected in their footpads with F. pedrosoi cells at an inoculum concentration of approximately 1 x 10(4) cells/mL. In one group, long-term cultured F. pedrosoi cells were inoculated in one footpad, whereas in the other group, both footpads were infected. Active lesions were observed up to seven months post-infection, particularly in mice inoculated at two sites. After this period, animals were killed. Histological sections revealed characteristics bearing a strong resemblance to the human form of the disease such as tissue hyperplasia, granulomas with microabscesses and sclerotic cells. Based on this study, we identified fungal cells from old cultures capable of provoking chronic chromoblastomycosis under experimental conditions, especially when more than one site is infected.(AU)

Isolation of herpotrichiellacious fungi from the environment

Herpotrichiellaceous fungi, common agents of chromoblastomycosis and phaeohyphomycosis, were searched in samples of rotten wood, leaf littler, bark and soil of the rhizosphere, collected in the Centro Nacional de Pesquisas de Florestas/EMBRAPA, Colombo, PR, Brazil. Morphological analyses of macro, optic and scanning electron microscopy, as well as the determination of the nutritional pattern of the isolated strains were carried out for a taxonomical study. In a total of 17 colonies, 3 isolates (17.6%) were identified as species of medical relevance: Cladophialophora bantiana (Sacc.) de Hoog et al., Fonsecaea pedrosoi (Brumpt) Negroni and Phialophora verrucosa Medlar. The identifications were based on the results of the analyses and on the comparison with CBS (Centraal Bureau voor Schimmelcultures) reference strains. This investigation revealed the saprophytic existence of species known as agents of chromoblastomycosis and phaeohyphomycosis. These diseases are considered autochthonous in the studied area.

Fungos da família Herpotrichiellaceae, agentes comuns de cromoblastomicose e feohifomicose, foram isolados de amostras de solo e de material vegetal em decomposição, durante duas coletas realizadas na propriedade do Centro Nacional de Pesquisa de Florestas/EMBRAPA, localizada em Colombo, PR, Brasil. Após o isolamento, os fungos foram submetidos às análises óticas macro e microscópicas e eletrônica de varredura, além do estudo de seus padrões nutricionais. Das 17 colônias de fungos isoladas, 3 (17,6%) foram identificadas como espécies de importância clínica, tais como: Cladophialophora bantiana (Sacc.) de Hoog et al, Fonsecaea pedrosoi (Brumpt) Negroni e Phialophora verrucosa Medlar. As identificações basearam-se nos resultados dos testes fisiológicos e na comparação da morfologia dos isolados com linhagens referência do CBS (Centraal Bureau voor Schimmelcultures). Esta investigação revelou a existência sapróbia de espécies de fungos conhecidas como agentes de cromoblastomicose e feohifomicose. Tais doenças são tidas como autóctones na região estudada.