Candida albicans の germ tube-like filament に関する研究 : 1. In vitro における germ tube-like filament 形成に関する実験

Abstract

The following results were obtained by observing various conditions and factors for germ tubes formation of C. albicans in vitro and examining the growth forms of the germ tubes by light microscopy and electron microscopy. 1. Optimum conditions for formation of germ tubes of C. albicans in serum were obtained when fungus cells that had been cultivated for 24 hours in Sabouraud's glucose agar medium at 37℃ were added at the rate of 1/32 (mg/ml) and were cultivated for 3 to 4 hours at 37℃. 2. On various influences in serum : Glucose, mitomycin C, and pH 5.0∿8.2 had no accelerative or obstructive effects, but streptomycin and UV radiation had obstructive effects on the formation of germ tubes. 3. Factors affecting formation of germ tubes : a). Addition of amino acids, glucose, vitamins singly or in combination produced no germ tubes. b). A marked decrease in the formation of germ tubes was observed when MgSO_4 was extracted from the Freis medium. c). Solid media were found to be more productive of germ tubes than liquid media. The use of S.C.L.T. medium, which helped to produce both germ tubes and chlamydospore, made it possible to identify C. albicans quickly and clearly. But vacuum culture led to a decrease in the formation of germ tubes. 4. Light and electron microscopic observation Light microscopic examination made it possible to distinguish between bud formation and germ tubes formation by showing that in germ tubes the septal wall takes a true mycelium-like form, is narrow in width, and elongates quickly by about 50μ in 2 or 3 hours. Observed electron microscopically in bud formation, the daughter cell wall consists of the three layers of the mother cell that are equally ellongated, while in germ tubes formation, the cell wall of the germ tubes consists of the inner most layer of the mother cell that has become thicker and longer. As for the organella in the cytoplasm, the endoplasmic reticulum was obscure, and large granules called storage body were found in the mother cell.