Citrobacter Explained

Citrobacter is a genus of Gram-negative, aerobic, rod-shaped^[1] coliform bacteria of the Enterobacteriaceae family.

Citrobacter spp. cause opportunistic infections (including urinary tract infections, gastroenteritis, and bacteremia).

Microbiology

Microbial biochemistry

The species C. amalonaticus, C. koseri, and C. freundii can use citrate as a sole carbon source. Citrobacter species are differentiated by their ability to convert tryptophan to indole (C. koseri is the only citrobacter to be commonly indole-positive), ferment lactose (C. koseri is a lactose fermentor), and use malonate.^[2]

Citrobacter shows the ability to accumulate uranium by building phosphate complexes.^[3]

Environmental microbiology

These bacteria can be found almost everywhere in soil, water, wastewater, etc. They can also be found in the human intestine.^{[4] [5]}

Clinical significance

Citrobacter are considered opportunistic nosocomial pathogens, typically associated with urinary tract infections and infant meningitis and sepsis.^[6]

Antimicrobial resistance

Citrobacter freundii strains have inducible ampC genes encoding resistance to ampicillin and first-generation cephalosporins.^[7] In addition, isolates of Citrobacter may be resistant to many other antibiotics as a result of plasmid-encoded resistance genes.

External links

• Citrobacter at DSMZ - German Collection of Microorganisms and Cell Cultures
• Canada Public Health Data Sheet

Notes and References

1. Web site: Dictionnaire médical de l'Académie de Médecine . Medical Dictionary of the Academy of Medicine . 2024-01-13 . www.academie-medecine.fr . fr.
2. Lipsky . Benjamin A. . Hook III . Edward W. . Smith . Arlene A. . Plorde . James J. . 1980 . Citrobacter Infections in Humans: Experience at the Seattle Veterans Administration Medical Center and a Review of the Literature . . 2 . 5 . 746–760 . 10.1093/clinids/2.5.746 . 1058-4838 . 6763304.
3. Macaskie . Lynne E. . Empson . Ruth M. . Cheetham . Anthony K. . Grey . Clare P. . Skarnulis . A. Jerome . 1992 . Uranium bioaccumulation by a Citrobacter sp. as a result of enzymically mediated growth of polycrystalline HUO₂PO₄ . Science . en . 257 . 5071 . 782–784 . 1992Sci...257..782M . 10.1126/science.1496397 . 0036-8075 . 1496397.
4. Drelichman . Vilma . Band . Jeffrey D. . 1985 . Bacteremias due to Citrobacter diversus and Citrobacter freundii. Incidence, risk factors, and clinical outcome . . 145 . 10 . 1808–1810 . 10.1001/archinte.145.10.1808 . 3899035.
5. Badger . Julie D. . M.F. Stins . Monique F. . Kim . Kwang Sik . 1999 . Citrobacter freundii Invades and Replicates in Human Brain Microvascular Endothelial Cells . . 67 . 8 . 4208–4215 . 96726 . 10417193.
6. Jabeen . Ishrat . Islam . Sohidul . Hassan . A. K. M. Imrul . Tasnim . Zerin . Shuvo . Sabbir R. . 2023 . A brief insight into Citrobacter species–a growing threat to public health . Frontiers in Antibiotics . 2 . 10.3389/frabi.2023.1276982/full . 2813-2467 . free.
7. Meini . Simone . Tascini . Carlo . Cei . Marco . Sozio . Emanuela . Rossolini . Gian Maria . 2019 . AmpC β-lactamase-producing Enterobacterales: what a clinician should know . Infection . en . 47 . 3 . 363–375 . 10.1007/s15010-019-01291-9 . 1439-0973.