AmpC - Organisms that produce AmpC beta-lactamase

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. Piperacillin/tazobactam, Ceftriaxone) when reported as susceptible likely reasonable for SIMPLE infections requiring SHORT duration.