Acid-fastness of fungi in blastomycosis and histoplasmosis
Wages, D.S.; Wear, D.J.
Archives of Pathology and Laboratory Medicine 106(9): 440-441
1982
ISSN/ISBN: 0003-9985 PMID: 6180697 Document Number: 183626
In 60% of the infections caused by Blastomyces dermatitidis and in 47% of the infections caused by Histoplasma capsulatum, some of the organisms are acid-fast in tissue sections. Treatment with 1N hydrochloric acid at 60 degrees C abolishes the acid-fastness of H capsulatum, which indicates that the acid-fastness may be related to mycolic acid. Organisms of B dermatitidis, however, remain acid-fast in 83% of the sections treated with acid. The presence of acid-fastness in small cells can aid in the differentiation of B dermatitidis and H capsulatum from Cryptococcus neoformans and Candida albicans, Persistent acid-fastness of organisms after treatment with heated acid helps identify B dermatitidis in tissue sections, especially when the strain is small or in other ways atypical.