Citrobacter

Citrobacter is a genus of Gram-negative coliform bacteria in the Enterobacteriaceae family.

The species C. amalonaticus, C. koseri, and C. freundii use solely citrate as a carbon source. Citrobacter species are differentiated by their ability to convert tryptophan to indole, ferment lactose, and utilize malonate.

Citrobacter shows the ability to accumulate uranium by building phosphate complexes.

Clinical significance
These bacteria can be found almost everywhere in soil, water, wastewater, etc. It can also be found in the human intestine. They are rarely the source of illnesses, except for infections of the urinary tract and infant meningitis and sepsis.

C. freundii strains have inducible ampC genes encoding resistance to ampicillin and first-generation cephalosporins. In addition, isolates of Citrobacter may be resistant to multiple other antibiotics as a result of plasmid-encoded resistance genes.