Usually susceptible to:

• Cephalosporins including first generation,

• Aminoglycosides,

• TMP-SMX,

• Fluoroquinolones

• Piperacillin-Tazobactam.

Almost always susceptible to:

• Carbapenems

• Aztreonam (special access)

• Colistin

Intrinsically resistant to ampicillin.

May be resistant to third generation cephalosporins (ESBLs), and rarely to carbapenems (carbapenemase enzymes).

Use fosfomycin and nitrofurantoin for uncomplicated UTI only