C. da S. Lacaz

Isolation and characterization of a Paracoccidioides brasiliensis strain from a dogfood probably contaminated with soil in Uberlândia, Brazil

We report the isolation of a strain of Paracoccidioides brasiliensis from a dogfood, probably contaminated with soil, in a Brazilian city. The fungus was isolated on appropriate culture media, and when inoculated into a guinea-pig testis produced orchitis with abundant fungal elements. Histopathology of sections of the testicle showed an inflammatory reaction with P. brasiliensis inside monocytes. Immunological identification confirmed the identity of the isolate.

Cutaneous and ungual phaeohyphomycosis caused by species of Chaetomium Kunze (1817) ex Fresenius, 1829

Two cases of cutaneous and ungual phaeohyphomycosis caused by species of Chaetomium are reported. The patients showed no clinical signs of immunodeficiency. In Case 1 there was a small, ulcerated, crusted lesion on the right forearm. Direct microscopical examination of material from this lesion showed light-brown hyphae with thick-walled cells. The fungus isolated was identified as Chaetomium globosum. Case 2 had lesions of the fingernails. Direct microscopy showed dematiaceous septate hyphae in the nail. The isolate from the nails was identified as Chaetomium perpulchrum. Identification of the fungi was based on the classification of Ames (1963) as adapted by Cooke (1986). Such infections due to Chaetomium species are rare.

Lack of reactivity of paracoccidioidomycosis sera in the double immunodiffusion test with the gp43 antigen: report of two cases

Sera from two patients with chronic active paracoccidioidomycosis yielded negative double immunodiffusion results with a culture filtrate antigen from Paracoccidioides brasiliensis routinely used in our laboratory. Complement fixation tests were positive for both sera using a polysaccharide-rich antigen. This study reports the results of a more extensive serological investigation of these two sera. Both a somatic antigen and a saline extract from the fungus yielded positive results in the double immunodiffusion. However, the immunodominant 43 kDa glycoprotein antigen showed negative results, although it was recognized by both sera in the Western blot assay. The value of the double immunodiffusion as a single serological test in paracoccidioidomycosis diagnosis is discussed.

Histoplasma capsulatum exoantigens obtained in neopeptone, glucose, thiamine and asparagine medium (NGTA).

The purpose of this work is obtaining exocellular antigens H and M from 4 H. capsulatum strains using NGTA medium (neopeptone, glucose, thiamine and asparagine) for periods of 1,2 and 3 months, at 36oC and continuously shaken. The exocellular antigens were evaluated by double immunodiffusion test against H. capsulatum rabbit antiserum, 7 histoplasmosis sera, 4 paracoccidioidomycosis sera and a reference antigen and antibody furnished by C.D.C. (Atlanta - USA). Except for the exocellular antigen from strain B.679 with 1 month of culture, all exocellular antigens obtained from the strains B.679, 58 and O187 showed the H and M bands. The A.811 strain demonstrated only the fraction H. All the exocellular antigens reacted positively with sera from histoplasmosis patients, except those obtained from strains 58 and B.679 with 1 month of culture. With regard to paracoc-cidioidomycosis patients sera, the exocellular antigens from strains 58 and O187 did not cross-react with them.The purpose of this work is obtaining exocellular antigens H and M from 4 H. capsulatum strains using NGTA medium (neopeptone, glucose, thiamine and asparagine) for periods of 1, 2 and 3 months, at 36 degrees C and continuously shaken. The exocellular antigens were evaluated by double immunodiffusion test against H. capsulatum rabbit antiserum, 7 histoplasmosis sera, 4 paracoccidioidomycosis sera and a reference antigen and antibody furnished by C.D.C. (Atlanta--USA). Except for the exocellular antigen from strain B.679 with 1 month of culture, all exocellular antigens obtained from the strains B.679, 58 and O187 showed the H and M bands. The A.811 strain demonstrated only the fraction H. All the exocellular antigens reacted positively with sera from histoplasmosis patients, except those obtained from strains 58 and B.679 with 1 month of culture. With regard to paracoccidioidomycosis patients sera, the exocellular antigens from strains 58 and O187 did not cross-react with them.O presente trabalho teve como objetivo a producao de exoantigenos H e M das amostras 58, B-679, A-811 e O187 de Histoplasma capsulatum, utilizando o meio NGTA (neopeptona, glicose, tiamina e asparagina) em periodos de cultivo de 1, 2 e 3 meses, a 36oC, sob agitacao constante (50 v.p.m.). Os antigenos brutos foram avaliados contra anti-soro e antigeno de Histoplasma capsulatum de referencia (Center for Disease Control), 4 soros de pacientes portadores de paracoccidioidomicose, 7 de histoplasmose e soro hiperimune anti-H. capsulatum produzido em coelhos, atraves da reacao de imunodifusao dupla. Verificou-se que, com excecao de B-679 com 1 mes de crescimento, todos os demais exoantigenos apresentaram as fracoes H e M de precipitacao. Os exoantigenos obtidos de A-811 apresentaram so a banda H. Excetuando-se os exoantigenos 58 e B-679 com 1 mes de crescimento, todos os demais exoantigenos reagiram contra soros de pacientes com histoplasmose. Em relacao aos soros de pacientes com paracoccidioidomicose, somente os exoantigenos 58 e O187 nao apresentaram reacao cruzada. Todos os exoantigenos reagiram frente ao soro hiperimune de coelho anti-H. capsulatum. Para obtencao de exoantigenos de H. capsulatum, sugerimos que as amostras sejam cultivadas sob as condicoes anteriormente descritas, adotando-se o periodo de 3 meses de crescimento, utilizando-se exoantigenos de referencia como controles da reacao.