β-Lactam and metronidazole administration are risk factors for carbapenemase-producing Enterobacterales acquisition in hospitalized dogs

Objective To identify risk factors for carbapenemase-producing, carbapenem-resistant Enterobacterales (CP-CRE) acquisition in dogs and cats during hospitalization. Methods A retrospective case-control study evaluating risk factors for acquiring CP-CRE during hospitalization in dogs and cats admitted from June 1, 2021, through September 30, 2023, was performed. Cases consisted of patients testing negative for CP-CRE at admission and positive prior to discharge. Control patients testing negative at admission and throughout hospitalization were matched to cases with a 3:1 ratio by species, managing service, and date and number of hospitalized days of CP-CRE testing. Patient demographics and characteristics were extracted from the electronic medical record. Conditional logistic regression modeling was performed to assess the association between these variables and being a case. Results 46 case dogs and 4 case cats were investigated. Due to the small number of cats, risk factors were only analyzed for dogs. On multivariable analysis, the odds of CP-CRE acquisition were significantly greater for dogs receiving a β-lactam antimicrobial (OR, 4.71; 95% CI, 1.32 to 16.82) or metronidazole (OR, 6.38; 95% CI, 1.71 to 23.74). All 4 case cats had received a β-lactam antimicrobial, and the majority (3 of 4 case cats) had received acid suppressants, were admitted from the emergency service, and had a central venous catheter or peripheral sampling line. Conclusions Receiving a β-lactam antimicrobial or metronidazole was an independent risk factor for CP-CRE acquisition in hospitalized dogs. Clinical Relevance These findings highlight the importance of antimicrobial stewardship.