THE IN-VITRO SUSCEPTIBILITY OF FONSECAEA-PEDROSOI TO ACTIVATED MACROPHAGES

Light and electron microscopy were used to analyze in vitro the intera ction of Fonsecaea pedrosoi with in vivo activated-macrophages. Adhere nce of the fungi to the surface of activated macrophages triggers the respiratory burst as revealed by reduction of nitroblue tetrazolium. T ransmission electron microscopy revealed NAD(P)H-oxidase activity in t he portions of the macrophage plasma of membrane that were in contact with the fungus as well as within phagocytic vacuoles. Activated macro phages failed to kill ingested fungi, but they showed a fungistatic ac tivity delaying germ tube and hyphae formation.