RAPID DESTRUCTION OF SKELETAL-MUSCLE FIBERS BY MYCELIAL GROWTH FORMS OF CANDIDA-ALBICANS

The process of tissue invasion by the yeast Candida albicans after sub cutaneous inoculation into the footpad of mice has been examined by li ght and electron microscopy. The blastospores germinated within 2 hr a fter injection. Hyphal and, to a lesser extent, pseudohyphal elements were observed penetrating into the adjacent striated muscle fibers and the endothelial cells of capillaries and destroying the collagen bund les of the interstitium. Electron microscopy showed evidence of struct ural tissue degradation associated with the mycelial elements, particu larly at the apical tip. This was presumably due to fungal enzymatic a ctivity. By 3 hr after infection, polymorphonuclear leucocytes had eng ulfed both the extracellular and intracellular mycelia, and often ther e was structural evidence of mycelial degradation. The results provide morphological evidence that initial tissue damage following subcutane ous infection is caused by the mycelial growth form. (C) 1995 Academic Press, Inc.