Intracellular Behavior of Histoplasma Capsulatum.

Howard, Dexter H. (University of California, Los Angeles). Intracellular behavior of Histoplasma capsulatum. J. Bacteriol. 87:33-38. 1964.-The tinctorial characteristics and intracellular generation time of Histoplasma capsulatum within mouse histiocytes maintained in tissue culture were studied. The appearance of viable and nonviable cells of H. capsulatum was observed after staining with the May Grunwald-Giemsa, Methenamine Silver, and Periodic acid-Schiff (PAS) procedures. Death of the fungus, either induced by heat or occurring naturally in saline suspension, caused a loss of nuclear differentiation. This loss was not accompanied by changes in the PAS or Silver staining capacities of the cell walls of the fungus. There was no tinctorial evidence for intracellular death of H. capsulatum in normal mouse histiocytes. The intracellular generation time of the fungus was estimated to be 10.3 +/- 1.5 hr, and was not affected by the age of the histiocytes. The generation time was approximately the same in histiocytes from Webster-Swiss and A/J mice.