Factors Contributing to Carbapenemase-Producing Carbapenem-Resistant Enterobacterales

Man with chest pain suffering from heart attack while sitting at home during the day.
Researchers compared different factors among US veterans with and without carbapenemase-producing carbapenem-resistant Enterobacterales cultures.

For patients with carbapenem-resistant Enterobacterales (CRE), the odds of having carbapenemase-producing CRE (CP-CRE) were greater for Black Americans and for patients with congestive heart failure (CHF) or gastroesophageal reflux disease (GERD), according to study results published in Clinical Infectious Diseases.

A retrospective study recruited 3096 US veterans with a positive culture for either non-CP-CRE or CP-CRE from 2013 to 2018. The patients were mostly White (74.1%), older than 65 years (74.8%), and men (95.1%).

The multivariable analysis of factors associated with CP-CRE was adjusted for race, admission type, bacterial species, CHF, chronic gastrointestinal illness, GERD, facility complexity, facility region, and year of culture.

Factors independently associated with increased odds of a positive CP-CRE culture were having a culture in the year 2017 (odds ratio [OR], 3.11; 95% CI, 2.13-4.54) or 2018 (OR, 3.93; 95% CI, 2.64-5.84), being Black (OR=1.44; 95% CI, 1.15-1.80), having GERD (OR, 1.39; 95% CI, 1.03-1.87), and having CHF (OR, 1.35; 95% CI, 1.11-1.64).

In 752 patients (24.3%), there was no documented antibiotic exposure in the year prior, and there were no significant differences in the rate of CP-CRE detection between patients with or without antibiotic exposure. Compared with patients with antibiotic exposure in the previous year, those without had lower rates of several comorbidities and a higher percentage of prolonged proton pump inhibitor use during the prior year.

Study limitations include the lack of generalizability of the study results outside of the veteran population, the inability to capture other meaningful clinical information retrospectively, and the small percentage (32.9%) of cultures that were tested for CP-CRE, including some that may have been misclassified. The Veterans Affairs definitions of CRE were used, which may have excluded cultures resistant to ertapenem alone.

According to the researchers, “More work should be done to determine the patient risk factors correlated to CP-CRE versus nonCP-CRE.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Wilson GM, Suda KJ, Fitzpatrick MA, et al; QUERI CARRIAGE Program. Risk factors associated with carbapenemase producing carbapenem-resistant Enterobacteriaceae (CP-CRE) positive cultures in a cohort of U.S. veterans. Clin Infect Dis. Published online May 11, 2021. doi:1093/cid/ciab415