Legionella pneumophila and Legionnaires' disease

Legionella pneumophila is a bacterial pathogen, which causes diseases such as Pontiac fever and Legionnaires' disease, also known as Legion Fever. Legionella pathogens, like some other bacteria, evolved by protecting themselves from attacks by single-celled organisms in soils such as soil amoebas, which were playing the key role in giving the title bacteria and disease their names [1]:

At an American Legion meeting in Philadelphia in 1976, amoebas containing Legionella bacteria were blown through air-conditioning ducts into the hotel and delivered deep into the conventioneer's lungs. Macrophages [white blood cells within tissues] in the humans' alveoli [primary sites of gas exchange with the blood in the respiratory system] ingested the Legionella, much as an amoeba would. Thirty-four people died of the resulting respiratory illness, and Legionnaires' disease was born.

Keywords: history, nomenclature, microbiology, legionellosis

Reference
[1] B. Brett Finlay: The Art of Bacterial Warfare. Scientific American February 2010, Volume 302, Number 2, pp. 57-63.