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Courtesy of CDC/ Dr. Barry S. Fields |
Trapped!
This electron micrograph depicts an amoeba (orange) as it entraps a bacterium (green) with an extended pseudopod. After it is ingested, the bacterium (Legionella pneumophila) can survive as a symbiont within what then becomes its protozoan host.
The amoeba (Hartmannella vermiformis) 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.