AmpC-producing Organisms

AmpC-producing Organisms


See 'Additional Information'


General Information

Gram negative organisms that have a chromosomal beta-lactamase.

Most common AmpC producing organisms: Citrobacter freundii, Enterobacter spp, and Klebsiella aerogenes.

Most AmpC organisms are healthcare encountered, are GI flora and are part of the Enterobacterales family.

Syndromes caused by the organism that possesses AmpC (see individual organism).

May require contact precautions if highly resistant.

ESBLs vs. AmpC: Most ESBLs are plasmid-encoded, whereas AmpCs are usually inducible and chromosomal.

In the lab, AmpCs test resistant to cefoxitin and cefotetan.

They test susceptible to aztreonam.

Possess the ability to become resistant to 3rd generation cephalosporins while on therapy