ESBL - Extended Spectrum Beta-Lactamase producing organisms

Some Gram negative bacilli produce "broad-spectrum" beta-lactamases that can hydrolyze penicillins and cephalosporins. Treatment of such organisms can often be challenging.

ESBL producing organisms carry genes that are found on plasmids in some strains of E. coli, K. pneumoniae and other organisms.

Use of penicillins (with or without beta-lactamase inhibitors) and cephalosporins should generally be avoided. Options for therapy (pending susceptibilities) include: nitrofurantoin (for cystitis only), TMP-SMX, carbapenems, aminoglycosides and fluoroquinolones.

ESBL producing organisms should be considered resistant to all beta-lactams except for carbapenems, which are the preferred therapy. While these organisms may be reported as susceptible to piperacillin-tazobactam or other beta-lactamase inhibitor combinations, treatment failures have been described.