Spectrum: Local Antimicrobial Stewardship, for Island Health

IAI ESBLs

ESBLs in IAI

ESBL enzymes are mostly found in E. coli and Klebsiella, but can also be present in other gram-negative bacilli (e.g. Enterobacter, Serratia)

ESBLs account for ~6.5% of all Enterobacteriaeceae in Island Health, a low but increasing rate

The gastro-intestinal tract is the main reservoir for ESBLs

Various studies have identified risk factors for ESBLs, with the most important being recent health-care exposure while traveling to areas with high prevalence (e.g. Asia)

Other strong risk factors:

  • previous colonization or infection with an ESBL isolate in the past 6 months

  • travel without health-care exposure, particularly to southern Asia

Less-associated risk factors:

  • frequent or prolonged antibiotic exposure

  • chronic indwelling vascular devices

  • hemodialysis

  • percutaneous feeding tube

  • prolonged systemic corticosteroids

Situations when anti-ESBL therapy should be used

  • isolation of ESBLs from an IA specimen

  • ESBL colonization

  • empiric treatment for critically ill patients with other ESBL risk factors (e.g. travel)

General Pathogen Information

ESBL-producing organisms

Treatment of ESBL-associated IAI

Empiric therapy

Piperacillin/Tazobactam 3.375g IV Q6H

If known ESBLs or very strongly suspected in critically ill

Meropenem 1g IV Q8H

Therapy Pearls

  • Piperacillin/tazobactam has activity against >90% of ESBLs

  • Carbapenems are considered the treatment of choice for known ESBLs, especially in high-inoculum infections (e.g. bacteremia, IAI without source control)

  • Studies are inconsistent in showing whether empiric use of piperacillin/tazobactam vs. a carbapenem is associated with worse outcomes

Oral Step-Down

Highly individualized depending on clinical scenario and susceptibilities

Potential Oral Options:
Amoxicillin/Clavulanate
Sulfamethoxazole-Trimetoprom
Doxycycline
Fluoroquinolones