Colistin-resistant Gram-negative bacteria isolated from the hospital water environment

The study aimed i) to investigate the presence of colistin-resistant (ColR) Gram-negative bacteria in the humid compartments of high-risk hospital units, ii) to characterize their phenotypic and molecular resistance profiles; iii) to investigate the persistence in time of resistant bacterial clones in the hospital humid environment. In addition, in order to investigate whether environmental isolates were responsible for HAIs or colonization, we reviewed retrospective hospital records searching for clinical ColR isolates from 2019 and 2020.