Wheatley Rachel M.; Caballero Julio Diaz; van der Schalk Thomas E.; De Winter Fien H. R.; Shaw Liam P.; Kapel Natalia; Recanatini Claudia; Timbermont Leen; Kluytmans Jan; Esser Mark; Lacoma Alicia; Prat-Aymerich Cristina; Oliver Antonio; Kumar-Singh Samir; Malhotra-Kumar Surbhi; Craig MacLean R.

Abstract: AbstractBacteria have the potential to translocate between sites in the human body, but the dynamics and consequences of within-host bacterial migration remain poorly understood. Here we investigate the link between gut and lungPseudomonas aeruginosapopulations in an intensively sampled ICU patient using a combination of genomics, isolate phenotyping, host immunity profiling, and clinical data. Crucially, we show that lung colonization in the ICU was driven by the translocation ofP. aeruginosafrom the gut. Meropenem treatment for a suspected urinary tract infection selected for elevated resistance in both the gut and lung. However, resistance was driven by parallel evolution in the gut and lung coupled with organ specific selective pressures, and translocation had only a minor impact on AMR. These findings suggest that reducing intestinal colonization ofPseudomonasmay be an effective way to prevent lung infections in critically ill patients. Nature Communications: 2022 doi: 10.1038/s41467-022-34101-2 https://doi.org/doi: 10.1038/s41467-022-34101-2