title: Antibiotic resistance in human peri-implantitis microbiota.
abstract: OBJECTIVE
  Because antimicrobial therapy is often employed in the treatment of infectious dental implant complications, this study determined the occurrence of in vitro antibiotic resistance among putative peri-implantitis bacterial pathogens.
  
  
  METHODS
  Submucosal biofilm specimens were cultured from 160 dental implants with peri-implantitis in 120 adults, with isolated putative pathogens identified to species level, and tested in vitro for susceptibility to 4 mg/l of doxycycline, 8 mg/l of amoxicillin, 16 mg/l of metronidazole, and 4 mg/l of clindamycin. Findings for amoxicillin and metronidazole were combined post-hoc to identify peri-implantitis species resistant to both antibiotics. Gram-negative enteric rods/pseudomonads were subjected to ciprofloxacin disk diffusion testing.
  
  
  RESULTS
  One or more cultivable submucosal bacterial pathogens, most often Prevotella intermedia/nigrescens or Streptococcus constellatus, were resistant in vitro to clindamycin, amoxicillin, doxycycline, or metronidazole in 46.7%, 39.2%, 25%, and 21.7% of the peri-implantitis subjects, respectively. Only 6.7% subjects revealed submucosal test species resistant in vitro to both amoxicillin and metronidazole, which were either S. constellatus (one subject) or ciprofloxacin-susceptible strains of gram-negative enteric rods/pseudomonads (seven subjects). Overall, 71.7% of the 120 peri-implantitis subjects exhibited submucosal bacterial pathogens resistant in vitro to one or more of the tested antibiotics.
  
  
  CONCLUSIONS
  Peri-implantitis patients frequently yielded submucosal bacterial pathogens resistant in vitro to individual therapeutic concentrations of clindamycin, amoxicillin, doxycycline, or metronidazole, but only rarely to both amoxicillin and metronidazole. Due to the wide variation in observed drug resistance patterns, antibiotic susceptibility testing of cultivable submucosal bacterial pathogens may aid in the selection of antimicrobial therapy for peri-implantitis patients.
authors.affiliation: Department of Periodontology and Oral Implantology, and Oral Microbiology Testing Service Laboratory, Temple University School of Dentistry, Philadelphia, PA, USA; Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA, USA; Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rams
authors.forename: John E
authors.initials: JE
authors.lastname: Degener
authors.forename: Arie J
authors.initials: AJ
authors.lastname: van Winkelhoff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000658:Amoxicillin / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects; D002939:Ciprofloxacin / Q000494:pharmacology; D002981:Clindamycin / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D057873:Peri-Implantitis / Q000188:drug therapy* / Q000382:microbiology*; D012189:Retrospective Studies
chemical_list: D008795:Metronidazole; D002981:Clindamycin; D002939:Ciprofloxacin; D000658:Amoxicillin; D004318:Doxycycline
keywords: antibiotic resistance; in vitro; peri-implantitis; submucosal microbiota