A water-system bacterium that causes Legionnaires’ disease when contaminated mist is breathed in. Explore its illustrative 3D model, human context, and sources.
L. pneumophila lives in water and grows inside free-living amoebae and protozoa, persisting in biofilms. CDC states that people can get Legionnaires’ disease, a type of serious pneumonia, when they breathe in mist containing the bacteria from building water systems, hot tubs and similar sources, and that in general it is not spread person to person. The same bacteria can cause Pontiac fever, a milder illness. Sixteen serogroups are recognized, and PHAC describes serogroup 1 as the most virulent and prevalent.
Risk comes from exposure to contaminated water aerosols rather than from contact with other people. CDC states that about 1 in 10 people who get sick with Legionnaires’ disease will die from complications, rising to about 1 in 4 for people who catch it during a stay in a healthcare facility, and that certain factors put people at increased risk.
Original schematic 3D phenotype. PHAC describes a Gram-negative, intracellular, aerobic organism that stains poorly and appears in different forms: a short rod 3-5 micrometres long in clinical specimens, with filamentous forms of 10-25 micrometres in culture. Motility is described as limited, with some strains completely non-motile, so flagella should be treated as conditional rather than assigned by default; the cited sheet describes no capsule or endospore. Colours, dimensions, layer thicknesses and displayed arrangements are diagram choices, not a measured individual cell. Independent scientific review remains pending.
Source check: 2026-09-19. Educational content; independent scientific review remains pending.