Tissue cultures of mouse peritoneal exudates inoculated with Blastomyces dermatitidis.

Observations on mouse monocytes, maintained in cell culture and inoculated with Histoplasma capsulatum, have been previously reported (Howard, 1959). H. capsulatum differs from other fungi pathogenic for man in that it is primarily a parasite of cells of the reticulo-endothelial system. Thus the fungus was ideally suited to preliminary studies on the usefulness of tissue culture techniques for the investigation of problems of the host-parasite relationship in the human mycoses. It was thought to be of interest to extend the observations to include Blastomyces dermatitidis, a fungus which is not characteristically a parasite of phagocytic cells, yet has certain biologic features in common with H. capsulatum. Both B. dermatitidis and H. capsulatum possess two morphologic forms: a yeast form in the tissues of an infected host and a mycelial form on culture media incubated at room temperature. On suitable culture media incubated at 37 C, the organisms may be converted to their yeastlike tissue phases. The present study reports observations on the behavior of B. dermatitidis in tissue cultures of mouse peritoneal exudates and compares these observations with those obtained under similar experimental conditions with H. capsulatum.