Clinical impact and early prediction of carbapenem-resistant Pseudomonas aeruginosa bacteraemia in allogeneic hematopoietic stem cell transplantation recipients

Abstract

Although antipseudomonal agents are administered in high-risk patients, no reports have focused on the risk of carbapenem-resistant (CR) Pseudomonas aeruginosa bacteremia in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. We retrospectively studied a cohort of adult allo-HSCT recipients with P. aeruginosa bacteremia, focusing on a comparison between carbapenem-sensitive (CS) and CR P. aeruginosa after initiating conditioning chemotherapy at our institute between January 2005 and December 2020. The incidence, all-cause 30-day mortality of P. aeruginosa bacteremia, and risk factors for carbapenem resistance among patients with P. aeruginosa bacteremia in allo-HSCT recipients were evaluated. Forty-eight patients with P. aeruginosa bacteremia were included, with an incidence of 3.84/100 recipients (CS 1.92 vs. CR 1.92). The all-cause 30-day mortality was significantly higher in CR P. aeruginosa bacteremia (CS 4.2% vs. CR 39.1%; p = 0.003). The factor significantly associated with CR P. aeruginosa bacteremia was carbapenem use for at least three days within 30 days before the onset of bacteremia (odds ratio: 9.23, 95% confidence interval: 2.52-33.67). Inappropriate antimicrobial selection was significantly more frequent in CR P. aeruginosa bacteremia (CS 4.2% vs. CR 66.7%; p ˂ 0.001). Empirical combination therapy with reference to antimicrobial susceptibility profiles in each institution should be considered when CR P. aeruginosa bacteremia is suspected in allo-HSCT recipients based on the risk of carbapenem exposure.