Microbe Memberships

The Scientific Classification of Legionella pneumophila:

Domain: Bacteria

Kingdom: Eubacteria

Phylum: Proteobacteria

Class: Gamma Proteobacteria

Order: Legionellales

Family: Legionellaceae

Genus: Legionella

Species: Legionella pneumophila

Here’s a closer look at what each level of classification reveals about Legionella pneumophila. 

Bacteria: Bacteria, Archaea and Eukarya are the three domains that make up the tree of life.  Legionella pneumophila is classified in bacteria because it has cell walls made of primarily peptidoglycan and is a prokaryotic, microscopic organism whose single cells have neither a membrane-bounded nucleus nor other membrane-bound organelles.

Eubacteria: Eubacteria, or true bacteria, are usually grouped into three types: rod-shaped (bacillus), spherical (coccus), or curved/helical. Legionella pneumophila bacteria are rod-shaped. 

Proteobacteria: Legionella pneumophila fits into this phylum because of the related rRNA sequences it shares with other members of this classification. Proteobacteria are Gram-negative which means they lose crystal violet stain but are stained pink when treated by Gram's method.

Gamma proteobacteria: This subdivision of proteobacteria has several distinguishing characteristics that explain why Legionella pneumophila and many other important pathogens belong. All are comprised of aerobic and fermentative gram-negative bacteria. Gammaproteobacteria is the largest and most diverse subgroup of proteobacteria. 

Legionellales: The bacteria classified in this order are aerobic, fermenting bacteria and it contains many of the major human pathogens like Legionella pneumophila.

Legionellaceae: Legionella pneumophila fits into this family of gram-negative, aerobic bacteria that do not form endospores or microcysts.

Legionella: All members of the Legionella genus, including Legionella pneumophila share a similar DNA-DNA hybridization. Legionella are usually ubiquitous in nature.

Legionella pneumophila: Bacteria of the species Legionella pneumophila are differentiated from other Legionella species by their unique biochemical analysis, fatty acid profiles, protein banding patterns, serology, DNA–DNA hybridization and analysis of  rRNA genes.

For a phylogenetic tree and information regarding how Legionella pneumophila is related to other organisms go to the Relative Relations page!