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Citrobacter is a genus of gram-negative coliform bacteria from the family Enterobacteriaceae , which is a relatively common opportunistic pathogen in humans. The most common species are Citrobacter freundii and Citrobacter koseri (referred to in the older literature as Citrobacter diversus ).

cultivation[edit | edit source]

Sensitivity and culture are similar to other enterobacteria . In Endo's soil, some strains are very similar to E. coli , while other strains are salmonella.

Biochemical properties[edit | edit source]

Representatives of the genus Citrobacter may form hydrogen sulfide , biochemically similar to salmonella. The genus is, of course, lactose positive , so it should not form bright colonies with a black center, for example on soil such as XLD ( xylose lysine deoxycholate ). Occasionally, strains that produce lactose may be delayed or not at all. In any case, they remain positive for the ONPG test (ortho-nitrophenyl-β-galactoside). When diagnosing the genus Citrobacter, it is important to keep in mind that antigens may cross-react with salmonella and similarly may STEC ( Shiga toxin producing E.coli ) strains.

Citrobacter Freundii

Pathogenicity[edit | edit source]

Citrobacter is an opportunistic pathogen in the gut. Its pathogenicity is also presented in the urinary tract and other infections include bacteremia , endocarditis , meningitis (even in newborns) and brain abscesses . In exceptional cases, it causes osteomyelitis in children. These complications are often caused primarily by intra-abdominal infections caused by non-infectious processes, such as gallstones or tumors in the abdominal cavity.

Virulence[edit | edit source]

Virulence factors include the aerobactin iron recovery system . In the case of brain infections, there is an increased ability to penetrate the blood-brain barrier .

Diagnostics[edit | edit source]

The diagnosis of the genus Citrobacter is based mainly on biochemistry. The ONPG test can be used to distinguish Citrobacter (delayed lactose fermentation) from Salmonella . An alternative method of resolution is the PYR-test (citrobacter - positive, salmonella - negative).

Transmission[edit | edit source]

Transmission is usually faecal-oral and parenteral infections are exclusively endogenous.

Therapy[edit | edit source]

Citrobacter is primarily resistant to cephalosporins I and II. generation. Co-amoxicillin , cephalosporins III , has been shown to be effective . generations are also effective, but must only be used in serious cases. And even in the case of Citrobacter, strains producing broad-spectrum beta-lactamase are increasing, especially low-virulent strains, which can transfer their genes encoding resistance to virulent strains of other enterobacteria.

Links[edit | edit source]

Source[edit | edit source]

  • VOTAVA, Miroslav, et al. Medical microbiology special. 1st edition. Brno: Neptun, 2003. 495 pp.  ISBN 80-902896-6-5 .

References[edit | edit source]

  • VOTAVA, Miroslav, et al. Medical microbiology special. 1st edition. Brno: Neptun, 2003. 495 pp.  ISBN 80-902896-6-5 .