2026 Eastern States Conference

Title
Impact of carbapenemase production on mortality in carbapenem-resistant organisms 

Authors
Katelyn Kelsey, PharmD; Jessica Hunt, PharmD; Rasha Abouelsaadate, PharmD, BCCCP

Learning Objective
Identify the difference in 30-day all-cause mortality in carbapenem-resistant organisms (CRO) bacteremia caused by carbapenemase-producing versus non-carbapenemase-producing strains.

Self-Assessment Question
The BCID panel was positive KPC producing Klebsiella pneumoniae. What is the preferred treatment of choice?

Background/Objective
The purpose of this study is to compare 30-day all-cause mortality in carbapenem-resistant organisms (CRO) bacteremia caused by carbapenemase-producing (CP) versus non-carbapenemase-producing strains.

Methods
This multi-site, retrospective cohort study included patients >18 years of age with initial bloodstream infection caused by organisms resistant to at least one carbapenem admitted between January 1, 2018, to July 30, 2025. Patients were excluded if they were pregnant, transitioned to end of life care or comfort care prior to completion of therapy or received treatment for CRO infection < 30 days from hospital admission. The primary outcome was all-cause mortality at 30 days. Secondary outcomes included treatment failure, recurrence, development of Clostridioides difficile infection, 30-day readmission rate and hospital length of stay.

Results
 A total of 19 records of CRO-positive bacteremia patients were screened and 14 subjects with CRO were included with 2 (14.3%) CP-CRO and 12 (85.7%) non-CP-CRO. The likely source of bacteremia was similar between the two groups. There were two carbapenemase types: KPC and NDM. A total of 3 patients (21.4%) died within 30 days, all of which were non-CP-CRO. The mean hospital length of stay was 17.5 days for non-CP-CRO and 14 days for CP-CRO. No subjects tested positive for Clostridioides difficile infection. Treatment failure was seen in four subjects (28.6%), both of which were in the non-CP-CRO group. No subjects experienced recurrence < 30 days. Hospital readmission (<30 days) occurred in two subjects in the non-CP-CRO producing group.

Conclusion 
There were similar rates in 30-day all-cause mortality in CP-CRO compared to non-CP-CRO producing groups. The study’s limitations include small sample size due to the specific inclusion of only bacteremia patients. The results presented are therefore exploratory and are not to provide definitive conclusions. The trends observed in the data can be used to generate hypotheses and guide future research.