title: Shifts in Campylobacter species abundance may reflect general microbial community shifts in periodontitis progression.
abstract: BACKGROUND
  Oral Campylobacter species have been found to be associated with periodontitis progression. While the etiological significance of Campylobacter rectus is quite established, the association of C. gracilis, C. concisus, and C. curvus with health or disease remains contradictory.
  
  
  OBJECTIVE
  This study hypothesizes that the proportion of species within the Campylobacter genus rather than the absolute abundance of a single species is a suitable indicator for periodontitis progression.
  
  
  METHODS
  Subgingival plaque from 90 periodontitis patients and gingival sulcus fluid of 32 healthy individuals were subjected to a newly developed nested PCR approach, in which all Campylobacter spp. were amplified simultaneously. The resulting mixture of 16S-rRNA-gene-amplicons were separated by single-stranded conformation polymorphism (SSCP) gel electrophoresis, followed by sequencing and identification of excised bands and relative quantification of band intensities. In all samples, the abundance of selected periodontitis marker species was determined based on DNA hybridization on a microarray.
  
  
  RESULTS
  The highly prevalent Campylobacter community was composed of varying proportions of C. rectus, C. gracilis, C. concisus, and C. curvus. Cluster analysis based on SSCP-banding pattern resulted in distinct groups which in turn coincided with significant differences in abundance of established periodontitis marker species (Tannerella forsythia, Porphyromonas gingivalis, and Fusobacterium nucleatum) and progression.
  
  
  CONCLUSIONS
  The shift in the Campylobacter community composition seems to display the general microbial community shift during clinical progression in a simplified manner. The focus on members of the Campylobacter in this study suggests that this genus can be an indicator of ecological changes in the subgingival oral microflora.
authors.affiliation: Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany; khenne@ukaachen.de.
authors.forename: Karsten
authors.initials: K
authors.lastname: Henne
authors.affiliation: Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Fuchs
authors.affiliation: Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kruth
authors.affiliation: Division of Virology, Institute of Medical Microbiology, RWTH Aachen University Hospital Aachen, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Horz
authors.affiliation: Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry & Periodontology, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Conrads
keywords: ParoCheck genechip; SSCP; microbial ecology; oral Campylobacter; periodontitis progression