Changing trends in the aetiology, treatment and outcomes of bloodstream infection occurring in the first year after solid organ transplantation: a single-centre prospective cohort study

To analyse trends in the aetiology, treatment and outcomes of bloodstream infection (BSI) within the first year post-transplant over the last 10-year period, we prospectively recorded all episodes of BSI occurring in solid organ transplant (SOT) recipients during the first year post-transplant from 2007 to 2016. Trends of factors were analysed by 2-year periods. Of 475 consecutive episodes of BSI, 218 occurred within a year of SOT in 178 SOT recipients. Gram-positive BSI decreased over time (40.5-2.2%). In contrast, there was a steady increase in Gram-negative bacilli (GNB) BSI (54.1-93.3%; P < 0.001), mainly due to Pseudomonas aeruginosa (2.4-20.4%) and Klebsiella pneumoniae (7.1-26.5%). Multidrug-resistant (MDR) GNB (4.8-38.8%; P < 0.001) rose dramatically, especially due to extended-spectrum β-lactamase (ESBL) production (7.1-34.7%). There was a sharp rise in the use of carbapenems, both as empirical (11.9-55.3%; P < 0.001) and as targeted antibiotic treatment (11.9-46.9%; P < 0.001). In conclusion, today, GNB are the leading causative agents of BSI in SOT recipients within the first year after SOT. In addition, MDR GNB have emerged mainly due to ESBL-producing strains. In spite of these changes, length of hospital stay, days of treatment and mortality have remained stable over time.