title: The evolution of Pseudomonas aeruginosa during antibiotic rotation in a medical intensive care unit: the RADAR-trial.
abstract: Bacterial spread between patients may contribute to the high prevalence of antibiotic-resistant pathogens within ICUs. The aim of this study was to evaluate the fate of Pseudomonas aeruginosa during the different antibiotic regimens. Susceptibility patterns and genotyping were performed to determine whether there was a predominant clone and to track the spread of resistant strains within the unit. Twenty-eight different ribotypes were found among 82 Pseudomonas isolates. Four ribotypes accounted for 42 (51%) isolates and were designated the "major clones" occurring throughout multiple cycles. The ribotypes with multiple occurrences were more resistant to antibiotics than ribotypes that appeared only once. The correlation of antibiotic use with antibiotic resistance and the finding of a large number of ribotypes suggested that de novo development of antibiotic resistance is a likely event in P. aeruginosa. In addition, ribotypes associated with antibiotic resistance appeared to have a survival advantage and can become frequent colonizers in the ICU.
authors.affiliation: Department of Medicine, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN 55415, USA. tsuka001@umn.edu
authors.forename: D T
authors.initials: DT
authors.lastname: Tsukayama
authors.forename: H J
authors.initials: HJ
authors.lastname: van Loon
authors.forename: C
authors.initials: C
authors.lastname: Cartwright
authors.forename: B
authors.initials: B
authors.lastname: Chmielewski
authors.forename: A C
authors.initials: AC
authors.lastname: Fluit
authors.forename: Chr
authors.initials: C
authors.lastname: van der Werken
authors.forename: J
authors.initials: J
authors.lastname: Verhoef
mesh_terms: D000900:Anti-Bacterial Agents / Q000145:classification / Q000627:therapeutic use*; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology; D004334:Drug Administration Schedule; D024881:Drug Resistance, Bacterial; D006801:Humans; D007362:Intensive Care Units; D011552:Pseudomonas Infections / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents