Scanning electron microscopy of pathogenic and non-pathogenic Naegleria cysts

Abstract Scanning electron microscopy of pathogenic and non-pathogenic Naegleria cysts. International journal for Parasitology 4: 139–142. Cysts of 4 strains of non-pathogenic Naegleria gruberi and 5 strains of pathogenic Naegleria fowleri were examined in the scanning electron microscope. Excystment of the Naegleria gruberi amoebae occurred via preformed exit pores in the cyst wall. Similar structures were not found in the cysts of Naegleria fowleri , and excystment occurred by rupture of the cyst wall. The sequence of cyst wall rupture is illustrated for one of the pathogenic strains.