The ''Legionellales'' are an order of '' Pseudomonadota'' ("Proteobacteria"). Like all ''Pseudomonadota'', they are

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

.George M. Garrity: '' Bergey's Manual of Systematic Bacteriology''. 2. Auflage. Springer, New York, 2005, Volume 2: ''The Proteobacteria, Part B: The Gammaproteobacteria'' They comprise two families, typified by ''

Legionella ''Legionella'' is a genus of gram-negative bacteria, gram-negative bacteria that can be seen using a silver stain or grown in a special media that contains cysteine, an amino acid. It is known to cause legionellosis (all illnesses caused by ''Legi ...

'' and '' Coxiella'', both of which include notable pathogens. For example, Q fever is caused by '' Coxiella burnetii'' and ''

Legionella pneumophila ''Legionella pneumophila'', the primary causative agent for Legionnaires' disease, Legionnaire's disease, is an Aerobic organism, aerobic, pleomorphic, Flagellum, flagellated, non-spore-forming, Gram-negative bacteria, Gram-negative bacterium. ' ...

'' causes

Legionnaires' disease Legionnaires' disease is a form of atypical pneumonia caused by any species of ''Legionella'' bacteria, quite often ''Legionella pneumophila''. Signs and symptoms include cough, shortness of breath, high fever, myalgia, muscle pains, and headach ...

and

Pontiac fever Pontiac fever is an acute, nonfatal respiratory disease caused by various species of Gram-negative bacteria in the genus ''Legionella''. It causes a mild upper respiratory infection that resembles acute influenza. Pontiac fever resolves spontaneo ...

. Members of the order ''Legionellales'' can be molecularly distinguished from other ''Gammaproteobacteria'' by the presence of four conserved signature indels (CSIs) in the proteins tRNA-guanine(34) transglycosylase, lipoprotein-releasing system transmembrane protein lolE and tRNA (guanosine(37)-N1)-methyltransferase TrmD.

References

External links

Legionellales
LPSN List of Prokaryotic names with Standing in Nomenclature Gammaproteobacteria Bacteria orders {{Legionellales-stub