title: Predominance of Lactobacillus spp. Among Patients Who Do Not Acquire Multidrug-Resistant Organisms.
abstract: The emergence and dissemination of multidrug-resistant organisms (MDROs) is a global threat. Characterizing the human microbiome among hospitalized patients and identifying unique microbial signatures among those patients who acquire MDROs may identify novel infection prevention strategies.
  
  
  
  Adult patients admitted to 5 general medical-surgical floors at a 649-bed, tertiary care center in Boston, Massachusetts, were classified according to in-hospital antimicrobial exposure and MDRO colonization status. Within 48 hours of hospital admission (baseline) and at discharge (follow-up), rectal swab samples were obtained, and compared with samples from an external control group of healthy persons from the community. DNA was extracted from samples, next-generation sequencing performed, and microbial community structure and taxonomic features assessed, comparing those who acquired MDROs and those who had not, and the external controls.
  
  
  
  Hospitalized patients (n = 44) had reduced microbial diversity and a greater abundance of Escherichia spp. and Enterococcus spp. than healthy controls (n = 26). Among hospitalized patients, 25 had no MDROs at the time of the baseline sample and were also exposed to antimicrobials. Among this group, 7 (28%) acquired ≥1 MDRO; demographic and clinical characteristics were similar between MDRO-acquisition and MDRO-nonacquisition groups. Patients in the nonacquisition group had consistently higher Lactobacillus spp. abundance than those in the acquisition group (linear discriminant score, 3.97; P = .04).
  
  
  
  The fecal microbiota of the hospitalized subjects had abnormal community composition, and Lactobacillus spp. was associated with lack of MDRO acquisition, consistent with a protective role.
authors.affiliation: Department of Medicine, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile.
authors.forename: Rafael
authors.initials: R
authors.lastname: Araos
authors.affiliation: Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine.
authors.forename: Albert K
authors.initials: AK
authors.lastname: Tai
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors.forename: Graham M
authors.initials: GM
authors.lastname: Snyder
authors.affiliation: New York University Langone Medical Center, New York.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Blaser
authors.affiliation: Rhode Island Hospital, Brown University, Providence.
authors.forename: Erika M C
authors.initials: EMC
authors.lastname: D'Agata
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001424:Bacterial Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007778:Lactobacillus / Q000235:genetics* / Q000302:isolation & purification; D064307:Microbiota / Q000187:drug effects / Q000235:genetics*; D011446:Prospective Studies; D012007:Rectum / Q000382:microbiology; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents
keywords: acquisition; hospital; microbiome; multidrug-resistant organisms; risk factors