2026 Southeastern Residency Conference

Title: Identification of risk factors for beta-lactam resistant Pseudomonas aeruginosa bacteremia   

Background: Pseudomonas aeruginosa bloodstream infections (BSI) are associated with significant morbidity and mortality. Increasing resistance to antipseudomonal beta-lactams, including piperacillin-tazobactam, cefepime, and carbapenems, has complicated empiric treatment strategies.  Currently, institutional risk factors for beta-lactam resistant P. aeruginosa are largely derived from studies of respiratory isolates, which may not accurately reflect resistance patterns or risk factors in bloodstream infections. The goal of this study is to evaluate risk factors for beta-lactam resistant Pseudomonas aeruginosa bacteremia. 

Methods: This retrospective cohort study included patients 18 years and older within the Prisma Health system with a positive blood culture for P. aeruginosa from March 1, 2021 to August 31, 2025. The first positive blood culture within a 12-month period was included. Patients were excluded if they had cystic fibrosis. The primary objective of this study was to identify patient-specific risk factors for beta-lactam resistant P. aeruginosa BSIs (defined as resistance to cefepime or piperacillin-tazobactam). The secondary objectives were to identify risk factors for carbapenem-resistant P. aeruginosa bacteremia, determine predictors for isolates with elevated minimum inhibitory concentrations (MICs), and evaluate susceptibility patterns to novel antibiotics. Multivariate logistic regression was performed to determine independent predictors of beta-lactam and carbapenem resistance, as well as factors associated with isolates exhibiting elevated MICs. 

Research & Conclusion: In progress