Capnocytophaga granulosa and Capnocytophaga haemolytica: novel species in subgingival plaque

Background: The oral cavity accommodates one of the most diverse microflora s in the human body. Knowledge of this microflora, and of the periodontal m icroflora in particular, proves crucial towards an understanding of the bac terial-host interactions which lead to the development of infectious inflam matory periodontal diseases. Capnocytophaga species have been implicated as putative periodontal pathogens. To date, only 3 members of this genus (C, gingivalis, C. ochracea and C. sputigena) have been isolated from subgingiv al plaque. Aim: This communication reports the isolation of 2 recently-speciated strai ns, namely C. granulosa and C. haemolytica, from subgingival plaque collect ed from adult periodontitis patients. Material and Methods: Subgingival plaque was collected from 29 patients wit h chronic adult periodontitis. Plaque samples were inoculated onto fastidio us anaerobe agar and incubated anaerobically for 5 days. Routine identifica tion of clinical isolates was performed by 16S rRNA PCR-RFLP analysis, usin g Cfo I as restriction enzyme and corroborated by 16S rRNA gene sequencing. Results: 16 of 29 patients (55%) tested positive for either C, granulosa an d or C. haemolytica. A total of 70 isolates (63 C. granulosa and 7 C. haemo lytica) were cultivated from subgingival plaque. 15 (51%) patients tested p ositive for C. granulosa, and 3 (10%) patients tested positive For C. haemo lytica. Conclusion: This is the Ist report which recounts the presence of C. granul osa and C, haemolytica in subgingival plaque. Further research is required to establish the relative proportions of these species subgingivally in hea lth and disease.