AmpC - Organisms that produce AmpC beta-lactamase


See 'Additional Information'

General Information

Gram negative organisms, usually "SPICEM" (see additional information), that have a chromosomal beta-lactamase

Most AmpC organisms are nosocomially encountered, are GI flora and are part of the Enterobacteriaceae family

Cause syndromes 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

SPICEM stands for Serratia, Pseudomonas and Providencia, (Indole positive) Proteus vulgaris, Citrobacter, Enterobacter, and Morganella