Citrobacter koseri
General Susceptibility

General Susceptibility

Carbapenem until susceptibility known, then step down to aminoglycoside or fluoroquinolone if susceptible.

These organisms usually produce inducible beta-lactamase which cause failure of 3rd generation beta-lactam therapy, despite in vitro susceptibility

Note that unlike C. freundii, C. koseri does not have an AmpC beta-lactamase gene