title: Miniaturized oligonucleotide arrays: a new tool for discriminating colonization from infection due to Staphylococcus aureus in diabetic foot ulcers.
abstract: OBJECTIVE
  We sought to evaluate the use of oligonucleotide arrays to discriminate colonization from infection due to Staphylococcus aureus in diabetic foot ulcers.
  
  
  METHODS
  We included diabetic patients hospitalized in a diabetic foot department for an episode of foot ulcer. Only patients who had no antibiotic treatment during the previous 6 months were included. At admission, ulcers were classified on clinical examination, according to the Infectious Diseases Society of America system. Seventy-two patients with a culture positive only for S. aureus as the sole pathogen were included. In individuals with a grade 1 ulcer, a second wound bacterial specimen was obtained 1 month later. Using oligonucleotide arrays, S. aureus resistance and virulence genes were compared between grade 1 and grades 2-4 ulcers.
  
  
  RESULTS
  S. aureus was initially isolated from 22 grade 1 and 50 grade 2-4 ulcers: 35 were methicillin resistant and 37 methicillin sensitive. In 20 grade 1 ulcers (92%), no virulence genes were identified, whereas these genes were present in all but 1 grade 2-4 ulcers. During follow-up, the two grade 1 ulcers that were infected with strains carrying virulence genes rapidly deteriorated; the array technology showed unchanged genotype profiles. On the contrary, two grade 1 ulcers healed: the genotype profiles were different from those at inclusion but without appearance of virulence genes.
  
  
  CONCLUSIONS
  The DNA array appears as a promising technique and is easy to perform. Our observational study suggests that it might help distinguish colonized grade 1 from infected grade 2 wounds, predict ulcer outcome, and contribute to a more adequate use of antibiotics.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, ESPRI 26, Université de Montpellier 1, UFR de Médecine, Avenue Kennedy, 30908 Nîmes Cedex 02, France.
authors.forename: Albert
authors.initials: A
authors.lastname: Sotto
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Richard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Jourdan
authors.forename: Christophe
authors.initials: C
authors.lastname: Combescure
authors.forename: Nicole
authors.initials: N
authors.lastname: Bouziges
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lavigne
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D004269:DNA, Bacterial / Q000235:genetics; D017719:Diabetic Foot / Q000382:microbiology*; D003937:Diagnosis, Differential; D005260:Female; D016523:Foot Ulcer / Q000382:microbiology*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D008904:Miniaturization; D020411:Oligonucleotide Array Sequence Analysis; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D006442:Glycated Hemoglobin