Magnified 3850X, this 2002 scanning electron microscope (SEM) image revealed some of the ultrastructural morphology exhibited by what is thought to be a single Hartmannella vermiformis amoeba cyst and debris artifact. The amoeba assumes the cystic stage of its life cycle under harsh conditions such as drought, or when there is an accumulation of environmental toxins, thus reducing its metabolic needs. Under these circumstances, the protozoan produces a protective coat and goes into a dormant state. CDC/Dr Rodney Donlan 2002