Carbapenemase-Producing Enterobacterales: An Increasing Threat to Australian Liver Transplant Recipients

Introduction: Carbapenemase-producing Enterobacterales (CPE) are associated with increased morbidity and mortality in liver transplant recipients (LTRs). There is a paucity of data regarding CPE colonization and infection in Australian LTRs.

Methods: A single-center retrospective cohort study of CPE was performed in LTRs from 2015 to 2024. LTRs underwent targeted screening and a period of enhanced screening to evaluate the incidence of CPE colonization. CPE infections were identified via clinical samples. All CPE isolates underwent whole genome sequencing. CPE isolation rates in LTRs were compared to the general hospital population and trends over time were analyzed.

Results: There were 31 episodes of CPE isolation (5 community acquired, 26 healthcare associated) from 28 LTRs. Nine episodes of CPE infection were found: urinary tract (n = 3), bloodstream (n = 3), wound/abscess (n = 2), and Salmonella gastroenteritis (n = 1). The remaining 22 episodes represented new CPE colonization. CPE Klebsiella pneumoniae was the most common bacterial species (n = 12) with the New Delhi metallo-β-lactamase (n = 13), the most common CPE gene detected. CPE isolation rates in LTRs increased over the study period (p = 0.06). The overall rate of CPE infection was significantly higher in LTRs than the general hospital population (1.92 vs. 0.30 per 10 000 occupied bed days, p = 0.04). Enhanced CPE screening identified an additional eight episodes of CPE colonization in 415 patients screened (1.9%).

Conclusion: CPE is an emerging threat for Australian LTRs and there is an urgent need to optimize strategies to prevent CPE colonization and infection in LTRs.