ESBL-Producing Enterobacterales Not a Causative Pathogen for Majority of Infections in ESBL-Producing Enterobacterales Carriers

Enterobacteriaceae Bacterium
Enterobacteriaceae Bacterium
Researchers investigated the relative proportions of ESBL-producing Enterobacterales vs non-ESBL-producing Enterobacterales infections in patients with ESBL-producing Enterobacterales colonization.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales may not be the causative pathogen in the majority of infections in hospitalized patients with a known history of ESBL-producing Enterobacterales colonization, according to study results published in Clinical Infectious Diseases.

In this retrospective cohort study performed at the University Hospital Basel in Switzerland, researchers investigated the relative proportions of ESBL-producing Enterobacterales vs non-ESBL-producing Enterobacterales infections in patients with ESBL-producing Enterobacterales colonization, as well as relevant risk factors for ESBL-producing Enterobacterales infections. Inclusion criteria was limited to hospitalized patients with detection of ESBL-producing Enterobacterales in any culture between January 2016 and December 2018 and at least one acute infection during that same hospitalization.

At total of 948 hospitalizations of patients (median age, 70 years; 48% women) known to be carriers of ESBL-producing Enterobacterales were identified. At least one acute infection was recorded in 572 hospitalizations of 428 unique patients. Of the 572 hospitalizations, 8% of patients had an ESBL-producing Enterobacterales infection as well as an infection without ESBL-producing Enterobacterales detection, 44% of patients were affected only by ESBL-producing Enterobacterales infections, and 47% of patients were infected with organisms not producing ESBL.

ESBL-producing Enterobacterales were identified as the causative pathogen in 45% of infections.

In the univariable analysis, variables associated with ESBL-producing Enterobacterales infections were age and dialysis, whereas stay in an intensive care unit, travel history, hospitalization abroad, history of ESBL colonization, and immunosuppressive therapy were associated with non-ESBL-producing Enterobacterales infections. With the exception of hospitalization abroad, all variables remained independently associated with infections in the multivariable analysis for non-ESBL-producing Enterobacterales infections, while age and dialysis remained associated with ESBL-producing Enterobacterales infections.

In a subgroup analysis limiting inclusion of patients with a pathogen identified in both groups, age and urinary catheterization were associated with ESBL-producing Enterobacterales infections.

Since urinary tract infections accounted for the majority of ESBL-producing Enterobacterales infections, site of infection “as well as patient-related exposures (eg, age and urinary catheterization) may be useful predictors of ESBL-[producing Enterobacterales] infections in ESBL-[producing Enterobacterales] carriers, potentially guiding empiric carbapenem therapy considerations,” stated the researchers. They noted, however, that their findings might not be generalizable to institutions with higher ESBL incidence, since this was a single-center study in a country with a low endemic ESBL incidence.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Vock I, Aguilar-Bultet L, Egli A, Tamma PD, Tschudin-Sutter S. Infections in patients colonized with extended-spectrum beta-lactamase-producing Enterobacterales – a retrospective cohort study [published online June 30, 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa895