Specific Fluorescein-Labeled Antiglobulins for the Yeast form of Paracoccidioides brasiliensis

Abstract
Summary Two lots of rabbit Paracoccidioides brasiliensis antiglobulins, produced against the yeast form of this fungus, were conjugated with fluorescein isothiocyanate. Both reagents brightly stained elements of the yeast and mycelial forms of 15 isolates of P. brasiliensis. In addition they cross reacted with the tissue form of Histoplasma capsulatum, Blastomyces dermatitidis, Sporotrichum schenckii and other heterologous fungi. Adsorption of one lot of labeled antibodies two times with yeast cells of S. schenckii and once with cells of the mycelial form of Coccidioides immitis rendered this conjugate specific for the yeast form of P. brasiliensis. Adsorption of the second conjugate once with mycelial growth of C. immitis followed by a single adsorption with yeast cells of H. capsulatum and one adsorption with cells of Rhodotorula sp. rendered it specific for the yeast form of P. brasiliensis.. The specific reagents stained P. brasiliensis cells in smears of clinical materials from four spontaneous human cases of South American blastomycosis. The specific reagents did not react with elements of the mycelial form of P. brasiliensis.