title: Natural history of colonization with gram-negative multidrug-resistant organisms among hospitalized patients.
abstract: OBJECTIVE
  To determine the anatomic sites and natural history of colonization with gram-negative multidrug-resistant organisms (MDROs).
  
  
  METHODS
  Prospective, longitudinal cohort study.
  
  
  METHODS
  Walter Reed Army Medical Center, a 236-bed tertiary care center in Washington, DC.
  
  
  METHODS
  Deployed subjects (ie, inpatients medically evacuated from Iraq or Afghanistan) or nondeployed subjects admitted to the same hospital.
  
  
  METHODS
  Consenting patients had 6 anatomic sites cultured every 3 days for 2 weeks and then weekly. Gram-negative organisms resistant to 3 or more classes of antibiotics were considered MDROs. Isolates were genotyped using pulsed-field gel electrophoresis. Clinical data, data on antibiotic use, and clinical culture results were collected.
  
  
  RESULTS
  Of 60 deployed subjects, 14 (23%) were colonized with an MDRO at admission, and 13 (22%) had incident colonization during hospitalization. The groin was the most sensitive anatomic site for detecting MDRO colonization, and all but one subject remained colonized for the duration of their hospitalization. Sixty percent of subjects with incident Acinetobacter colonization and 25% of subjects with incident Klebsiella colonization had strains that were related to those isolated from other subjects. Of 60 nondeployed subjects, 5 (8%) were colonized with an MDRO at admission; all had recent healthcare contact, and 1 nondeployed subject had an isolate related to a strain recovered from a deployed subject.
  
  
  CONCLUSIONS
  Colonization with gram-negative MDROs is common among patients with war-related trauma admitted to a military hospital and also occurs among nondeployed patients with recent healthcare contact. The groin is the most sensitive anatomic site for active surveillance, and spontaneous decolonization is rare.
authors.affiliation: Uniformed Services University of the Health Sciences, Infectious Disease Clinical Research Program, Bethesda, Maryland, USA. Amy.Weintrob@us.army.mil
authors.forename: Amy C
authors.initials: AC
authors.lastname: Weintrob
authors.forename: Mollie P
authors.initials: MP
authors.lastname: Roediger
authors.forename: Melissa
authors.initials: M
authors.lastname: Barber
authors.forename: Amy
authors.initials: A
authors.lastname: Summers
authors.forename: Ann M
authors.initials: AM
authors.lastname: Fieberg
authors.forename: James
authors.initials: J
authors.lastname: Dunn
authors.forename: Venus
authors.initials: V
authors.lastname: Seldon
authors.forename: Fluryanne
authors.initials: F
authors.lastname: Leach
authors.forename: Xiao-Zhe
authors.initials: XZ
authors.lastname: Huang
authors.forename: Mikeljon P
authors.initials: MP
authors.lastname: Nikolich
authors.forename: Glenn W
authors.initials: GW
authors.lastname: Wortmann
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015331:Cohort Studies; D004219:District of Columbia; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D006119:Groin / Q000382:microbiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006772:Hospitals, Military; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009928:Organ Specificity; D015995:Prevalence; D011446:Prospective Studies; D012007:Rectum / Q000382:microbiology; D014481:United States; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents