title: Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE): a promising tool to diagnose bacterial infections in diabetic foot ulcers.
abstract: OBJECTIVE
  The diagnosis of diabetic foot infections is difficult due to limitations of conventional culture-based techniques. The objective of this study was to evaluate the contribution of denaturing gradient gel electrophoresis (DGGE) in the microbiological diagnosis of diabetic foot ulcers in comparison to conventional techniques, and also to evaluate the need to perform a biopsy sample for this diagnosis.
  
  
  METHODS
  Twenty diabetic patients (types 1 and 2) with foot ulcers (grades 1-4) were included. After debridement of their wounds, samples were taken in duplicate by surface swabbing and deep-tissue biopsy. The samples were analyzed by conventional culture and by a new molecular biology tool, DGGE technology.
  
  
  RESULTS
  Polymerase chain reaction (PCR)-DGGE led to the identification of more bacteria than did conventional cultures (mean: 2.35 vs 0.80, respectively). In 11 cases, the technology detected pathogenic species not isolated by classical cultures. PCR-DGGE also identified significantly more pathogenic species at deep levels compared with species detected at superficial levels (87% vs 58%, respectively; P = 0.03). In 9/20 cases, pathogenic bacteria were detected only in deep samples, revealing the need to perform tissue biopsy sampling.
  
  
  CONCLUSIONS
  DGGE, achievable in 48h, could be a useful technique for the bacteriological diagnosis of diabetic foot infections. It may help to identify pathogenic bacteria in deeply infected ulcers, thereby contributing to a more appropriate use of antibiotics.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U1047, Université de Montpellier 1, 30908 Nîmes, France; Department of Microbiology, CHU Carémeau, 30029 Nîmes, France.
authors.forename: C
authors.initials: C
authors.lastname: Dunyach-Remy
authors.affiliation: EHESP Rennes, Sorbonne Paris Cité, INSERM-UMR-IRSET, U1085, LERES, 35000 Rennes, France.
authors.forename: A
authors.initials: A
authors.lastname: Cadière
authors.affiliation: Department of Diabetology, CHU de Nîmes, 30240 Le Grau-du-Roi, France.
authors.forename: J-L
authors.initials: JL
authors.lastname: Richard
authors.affiliation: Department of Diabetology, CHU de Nîmes, 30240 Le Grau-du-Roi, France.
authors.forename: S
authors.initials: S
authors.lastname: Schuldiner
authors.affiliation: Centre LGEI, École des Mines d'Alès, 30100 Alès, France.
authors.forename: S
authors.initials: S
authors.lastname: Bayle
authors.affiliation: EHESP Rennes, Sorbonne Paris Cité, INSERM-UMR-IRSET, U1085, LERES, 35000 Rennes, France.
authors.forename: B
authors.initials: B
authors.lastname: Roig
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U1047, Université de Montpellier 1, 30908 Nîmes, France.
authors.forename: A
authors.initials: A
authors.lastname: Sotto
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, U1047, Université de Montpellier 1, 30908 Nîmes, France; Department of Microbiology, CHU Carémeau, 30029 Nîmes, France. Electronic address: jean.philippe.lavigne@chu-nimes.fr.
authors.forename: J-P
authors.initials: JP
authors.lastname: Lavigne
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis / Q000379:methods*; D017719:Diabetic Foot / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies
keywords: Antibiotic treatment; Denaturing gradient gel electrophoresis; Diabetic foot ulcer; Diagnostic; Ecology; Infection