Macrophage infected with the bacterial pathogen Legionella pneumophila

Legionella pneumophila

Legionella pneumophila is the cause of a severe pneumonia called Legionnaires' Disease. Inside human hosts, Legionella replicates within an immune cell called the macrophage (shown in green). In this image, a special staining technique was employed to differentially label bacteria inside the macrophage (red) versus those outside the macrophage (blue).

Image courtesy of Russell Vance Lab