1. Gram negative , obligate aerobes 2) Utilize amino acids, but not carbohydrates as a source of carbon and energy. 3) Often live intracellularly within protozoa & macrophages. 4) Isolated from water in air conditioners & produce misters 5) Legionella pneumophila - Legionnaire's disease

Legionella pneumophila belongs to the kingdom Bacteria. It is a Gram-negative bacterium that thrives in aquatic environments and can cause a severe form of pneumonia known as Legionnaires' disease when inhaled by humans.

"Spp" in Legionella spp stands for "species". It indicates that there are multiple species within the Legionella genus, such as Legionella pneumophila and Legionella longbeachae.

Legionella is a group of bacteria - microorganisms.

'Pneumonia' is the Latin term for a inflammatory illness of the lung. Among the different types of legionella bacteria there are some that can duplicate themselves in the lungs. These are the so-called legionella pneumophila. When in high enough numbers, they represent a direct thread to the human immune system. The 'plain' legionella do not (in the majority of cases!), although they are of the same family of bacteria as the legionella pneumophila and there exists a discussion whether (1) the occurrence of the 'plain' legionella means the conditions are also fit for the legionella pneumophila to grow or (2) the 'plain' legionella might be dominant enough to prevent the legionella pneumophila of growing.