title: Microbiotica associated with refractory periodontis. Prevalence and antibiotic susceptibility.
abstract: BACKGROUND
  The aim of the present study was to analyze the composition of subgingival microflora in patients with refractory periodontitis and to evaluate the antimicrobial sensitivity of isolated periodontopathic microorganisms to different antibiotics.
  
  
  METHODS
  Eleven subjects with a mean age of 46.4 years were selected for the present study. All had been treated for periodontal disease in the past. After further disease progression patients were included in this study. Eight subgingival plaque samples per patients were collected for cultural analysis.
  
  
  RESULTS
  "Black pigmenting anaerobic bacilli" were the pathogenic microorganisms more frequently isolated. The findings from antibiotic susceptibility test showed that high number of bacteria associated with refractory periodontitis resulted resistant to erythromycin, metronidazole and tetracycline. The most effective antibiotics were ciprofloxacin, amoxicillin-metronidazole and amoxicillin-clavulanic acid.
  
  
  CONCLUSIONS
  Microbiological analysis and antibiotic susceptibility test should be considered important tools in the management of patients with poor clinical response to conventional periodontal treatment.
authors.affiliation: Chair of Periodontology, Faculty of Medicine and Surgery, University of Pisa.
authors.forename: A
authors.initials: A
authors.lastname: Barone
authors.forename: L
authors.initials: L
authors.lastname: Sbordone
authors.forename: L
authors.initials: L
authors.lastname: Ramaglia
authors.forename: R N
authors.initials: RN
authors.lastname: Ciaglia
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001421:Bacteria, Anaerobic / Q000302:isolation & purification / Q000472:pathogenicity; D004917:Erythromycin / Q000627:therapeutic use; D005881:Gingiva / Q000382:microbiology*; D006801:Humans; D008795:Metronidazole / Q000627:therapeutic use; D009061:Mouth Mucosa / Q000382:microbiology*; D010518:Periodontitis / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D013752:Tetracycline / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D004917:Erythromycin; D013752:Tetracycline