ABSTRACT
The mycologic diagnosis of paracoccidioidomycosis is basically established by microscopic demonstration of its etiological agent Paracoccidioides brasiliensis, followed by isolation and later identification. The procedure of the mycologist or clinical pathologist in mycologic diagnosis will depend on the type of lesion presented by the patient. The new stains routinely used in clinical pathology laboratories, the R. G. Grocott method in particular, have permitted a better visualization of Paracoccidioides brasiliensis. When the material contains rare P. brasiliensis forms, inoculation into the guinea pig testis is recommended since the procedure induces orchitis, which is rich in parasites. A slow-growing fungus, depending on the number of parasites in the material inoculated, P. brasiliensis can be easily isolated when so-called contaminating bacteria are not present. According to A. Restrepo and L. E. Cano, the best medium for P. brasiliensis isolation is yeast extract agar.
