AmpC - Organisms that produce AmpC beta-lactamase

General Susceptibility

Intrinsic resistance to Ampicillin and lower generation cephalosporins. With exposure to beta-lactams, induction or de-repression can occur and confer resistance to third generation cephalosporins.

Susceptible to carbapenems

Usually susceptible to fluoroquinolones, TMP-SMX, and aminoglycosides which are appropriate targeted therapy options.

Using non-carbapenem beta-lactams (i.e. Pip-Tazo, Ceftriaxone) when reported as susceptible likely reasonable for SIMPLE infections requiring SHORT duration.

Usually sensitive to aztreonam.