Cryptococcus neoformans: gastronomic delight of a soil ameba.
During 7 days of incubation in vitro the trophozoite stage of the free-living soil amoeba, Acanthamoeba polyphaga, phagocytized and killed 78-97% of the cells of three strains of Cryptococcus neoformans. With one strain, incubation time was increased to nine days and 99% of the yeast cells were killed. It was calculated that during 4-9 days of incubation a single trophozoite phagocytized and killed a daily average of 84 yeast cells. The lethal effect of A. polyphaga on C. neoformans may represent a biological control mechanism in nature. Some of the surviving cells of C. neoformans developed into colonies containing pseudohyphae; these pseudolhyphal forms may be a biological 'escape hatch'.
D000656:Amoeba / Q000502:physiology*; D000818:Animals; D003454:Cryptococcus / Q000502:physiology*; D003455:Cryptococcus neoformans / Q000254:growth & development / Q000502:physiology*; D010587:Phagocytosis; D012988:Soil Microbiology