title: A genomic analysis of Clostridium difficile infections in blunt trauma patients.
abstract: BACKGROUND
  Evidence demonstrates that susceptibility to Clostridium difficile infection is related to host risk factors as much as bacterial potency. Using blood leukocyte genome-wide expression patterns of severe blunt trauma patients obtained by the National Institute of General Medical Sciences-sponsored Glue Grant Inflammation and the Host Response to Injury, we examined leukocyte genomic profiles of patients with C. difficile infection to determine preinfection and postinfection gene expression changes.
  
  
  METHODS
  The genomic responses of 21 severe trauma patients were analyzed (5 C. difficile, 16 controls matched for age and severity of injury). After elimination of probe sets whose expression was below baseline or were unchanged, remaining probe sets underwent hierarchical clustering and principal component analysis. Molecular pathways were generated through Ingenuity Pathways Analysis.
  
  
  RESULTS
  Supervised analysis demonstrated 118 genes whose expression in patients with C. difficile infection varied before and after their infection. Supervised analysis comparing patients with C. difficile infection with matched non-C. difficile patients before infection suggested that the expression of 501 genes were different in the two groups with up to 87% class prediction (p < 0.05). Many of these genes are related to cell-mediated immune responses, signaling, and interaction.
  
  
  CONCLUSIONS
  Genomic analysis of severe blunt trauma patients reveals a distinct leukocyte expression profile of C. difficile both before and after infection. We conclude that an association may exist between a severe trauma patient's leukocyte genomic expression profile and subsequent susceptibility to C. difficile infection. Further prospective expression analysis of this C. difficile population may reveal potential therapeutic interventions and allow early identification of C. difficile-susceptible patients.
  
  
  METHODS
  Prognostic/diagnostic study, level III.
authors.affiliation: Department of Surgery, University of Florida, Gainesville, Florida 32610, USA.
authors.forename: Philip Alexander
authors.initials: PA
authors.lastname: Efron
authors.forename: Huazhi
authors.initials: H
authors.lastname: Liu
authors.forename: Lawrence
authors.initials: L
authors.lastname: Lottenberg
authors.forename: Alex Gervacio
authors.initials: AG
authors.lastname: Cuenca
authors.forename: Lori Filichia
authors.initials: LF
authors.lastname: Gentile
authors.forename: Makesha Vernee
authors.initials: MV
authors.lastname: Miggins
authors.forename: Azra
authors.initials: A
authors.lastname: Bihorac
authors.forename: Henry V
authors.initials: HV
authors.lastname: Baker
authors.forename: Frederick Alan
authors.initials: FA
authors.lastname: Moore
authors.forename: Lyle Linc
authors.initials: LL
authors.lastname: Moldawer
authors.forename: Darwin N
authors.initials: DN
authors.lastname: Ang
mesh_terms: D003015:Clostridium Infections / Q000150:complications* / Q000235:genetics*; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007962:Leukocytes; D020411:Oligonucleotide Array Sequence Analysis; D012307:Risk Factors; D014946:Wound Infection / Q000382:microbiology*; D014949:Wounds, Nonpenetrating / Q000382:microbiology*