Management of ESBL Bacteremia with Urinary Source

Introduction to Treatment Guidelines

The World Health Organization documents resistance rates of 60-93% in ESBL-producing E. coli to fluoroquinolones, making them unreliable even when susceptibility testing suggests otherwise 1
The Infectious Diseases Society of America specifically recommends avoiding fluoroquinolones empirically due to high resistance rates, reserving them only for patients with confirmed susceptibility AND beta-lactam allergies—and even then, NOT for bacteremia 1

The American College of Physicians and other guideline societies recommend that for ESBL bacteremia with urinary source in a patient, Group 2 carbapenems (meropenem 1g IV every 8 hours, imipenem-cilastatin 1g IV every 8 hours, or doripenem 500mg IV every 8 hours) remain the drugs of choice for the full treatment course 2
Treatment duration should be 10-14 days for bacteremia with urinary source, with 14 days particularly important in male patients when prostatitis cannot be excluded 2

Once the patient is afebrile for 24-48 hours, tolerating oral intake, and clinically improving with documented clearance of bacteremia, the only acceptable oral options based on susceptibility results are fosfomycin (3g single dose, may repeat in 3 days) or pivmecillinam—NOT fluoroquinolones 1

Ceftazidime-avibactam 2.5g IV every 8 hours is an effective carbapenem-sparing option with excellent activity against ESBL-producing organisms if carbapenem resistance is a concern in your institution 2
Intravenous fosfomycin demonstrates non-inferiority to meropenem for bacteremic UTI caused by E. coli, though it carries an 8.6% risk of heart failure versus 1.4% with meropenem, requiring monitoring in at-risk patients 1

Remove or replace any indwelling urinary catheter if present, as catheter-associated UTI is a major risk factor for bacteremia in neurogenic bladder patients 2
Piperacillin-tazobactam is controversial and NOT recommended for bacteremia due to ESBL organisms, even in stable patients, despite possible in vitro susceptibility 2