Foto de stock - PHAGOCYTOSIS<BR>Amoeba (Hartmannella vermiformis) capturing a Legionella pneumophila bacterium.<BR>This electron micrograph depicts an amoeba, Hartmannella vermiformis (orange) as it entraps a Legionella pneumophila bacterium (green) with an extended pseudopod After it is ingested, the Legionella pneumophila bacterium can survive as a symbiont within what then becomes its protozoan host. The amoeba then becomes what is referred to as a ´Trojan horse´, for by harboring the pathogenic bacteria, the amoeba can afford them protection, and in fact, in times of adverse environmental conditions, are able to metamorphose into a cystic stage enabling it, and its symbiotic resident pathogens, to withstand such environmental stresses.