Amoeba entrapping Legionella pneumophila bacterium

Categories: Health & Hygiene

Amoeba entrapping Legionella pneumophila bacterium


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.

Source: CDC

Link to hi-res version:


Amoeba entrapping Legionella pneumophila bacterium:  Created on September 9th, 2007.  Last Modified on November 4th, 2009


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