Citrobacter sedlakii is a species of

Gram-negative bacteria Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

. It has been described as causing human disease, but is generally found as a non-pathogenic organism in human stools.

History

''Citrobacter sedlakii'' was originally isolated from human stool and wounds as strains of ''

Citrobacter freundii ''Citrobacter freundii'' is a species of facultative anaerobic Gram-negative bacteria of the family Enterobacteriaceae which currently consists of 13 recognized species. These bacteria have a rod shape with a typical length of 1–5 μm. Most ''C ...

''. However, in 1993 six strains of ''C. freundii'' were identified as a separate species based on DNA hybridization, and were named ''C. sedlakii'' to honor Czech microbiologist Jiri Sedlak.

Description

''Citrobacter sedlakii'' is a

rod-shaped A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name '' Bacil ...

gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

bacterium. It can be distinguished from other ''

Citrobacter ''Citrobacter'' is a genus of Gram-negative coliform bacteria in the family Enterobacteriaceae. The species ''C. amalonaticus'', ''C. koseri'', and ''C. freundii'' can use citrate as a sole carbon source. ''Citrobacter'' species are differentia ...

'' species by its ability to produce

indole Indole is an aromatic heterocyclic organic compound with the formula C8 H7 N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indole is widely distributed in the natural environme ...

arginine dihydrolase In enzymology, an arginine deiminase () is an enzyme that catalyzes the chemical reaction :L-arginine + H2O \rightleftharpoons L-citrulline + NH3 Thus, the two substrates of this enzyme are L-arginine and H2O, whereas its two products are L ...

activity, and

ornithine decarboxylase The enzyme ornithine decarboxylase (, ODC) catalyzes the decarboxylation of ornithine (a product of the urea cycle) to form putrescine. This reaction is the committed step in polyamine synthesis. In humans, this protein has 461 amino acids and for ...

activity.

Role in disease

''Citrobacter sedlakii'' was originally isolated from human stool and wounds and was suggested to be

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

ic in humans. While some reports have described ''C. sedlakii'' as causing illness in humans, it is frequently found in stool and is not thought to be pathogenic in most cases. ''C. sedlakii'' can express the O157 antigen which is commonly found on pathogenic ''

E. coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

'', however this does not cause disease.

References

External links

*
LPSNType strain of ''Citrobacter sedlakii'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
sedlakii Bacteria described in 1993 {{Enterobacterales-stub