Predictors of carbapenem-resistant Enterobacterales enteric colonization among patients admitted to a companion animal intensive care unit

Objective: To estimate prevalence and identify factors associated with carbapenem-resistant Enterobacterales (CRE) enteric colonization in companion animals admitted to an ICU. Methods: The study population included canine and feline patients admitted to The Ohio State University Veterinary Medical Center ICU between January 2024 and June 2025. In total, 5,552 rectal swabs were collected from 3,834 patients during routine screening. A retrospective case-control study included all CRE-positive patients (n = 61) and randomly selected CRE-negative controls (137). Cases were defined as ICU patients with at least 1 positive CRE fecal culture during hospitalization, whereas controls had no positive CRE fecal cultures during their hospitalization. Results: Prevalence of CRE colonization was 1.59% (61 of 3,834 patients; 95% CI, 1.24% to 2.04%). Escherichia coli carrying blaNDM was the most frequently identified isolate, accounting for 78.7% (48 of 61 patients; 95% CI, 66.9% to 87.1%). Predictors of CRE colonization included increased comorbidity burden (unit OR, 1.96; 95% CI, 1.43 to 2.75), intact reproductive status (OR, 4.39; CI, 1.47 to 11.03), longer hospitalization (unit OR, 1.31; CI, 1.14 to 1.53), recent surgery (OR, 2.72; CI, 1.29 to 5.87), and antimicrobial use within the previous 3 months (OR, 2.71; CI, 1.23 to 6.07). Conclusions: These predictors suggest targets for infection prevention and control measures to protect patients and staff. The association between recent antimicrobial exposure and CRE colonization reinforces the importance of antimicrobial stewardship in veterinary medicine. Clinical Relevance: Although uncommon, CRE-colonized patients can serve as reservoirs for transmission and are at risk of subsequent infection.