The phylum Synergistetes in gingivitis and necrotizing ulcerative gingivitis

Abstract

The clinical manifestation of necrotizing ulcerative gingivitis (NUG) is distinct from that of common gingivitis in that it is characterized by local necrosis of the gingival tissues, rapid onset, pain and extensive bleeding. The phylum Synergistetes is a novel bacterial phylum consisting of Gramnegative anaerobes, with evidence of presence in biofilms associated with periodontal and endodontic infections. To date, the involvement of members of this phylum in NUG has not been investigated. This study aimed to evaluate the presence and levels of known human oral Synergistetes bacterial clusters in dental plaque from patients with NUG and compare them with those found in gingivitis. Marginal dental plaque samples from 21 NUG and 21 gingivitis patients were analysed quantitatively by fluorescent in situ hybridization and microscopy for members of two oral Synergistetes clusters (A and B) and for Jonquetella anthropi. Synergistetes cluster A bacteria were detected in all samples but at higher levels (9.4-fold) and proportions (2.5-fold) in NUG patients than in gingivitis patients. However, with regard to Synergistetes cluster B bacteria, there were no differences between NUG and gingivitis patients. J. anthropi was detected in only half of the samples and at lower levels than the other taxa. In conclusion, these data demonstrate that Synergistetes cluster A bacteria, but not cluster B bacteria or J. anthropi, are more strongly associated with NUG than with gingivitis.

Identification of Synergistetes in endodontic infections

“…Their prevalence as well as detection range was greater in R-AP compared to N-AP. Synergistetes cluster B was not detected in any of the three clinical diagnosis groups, implying that it is not crucial in the establishment of AP, as has also been demonstrated in the case of marginal periodontal diseases [6,8].…”

“…The presence of Synergistetes in dental plaque is also more pronounced in necrotizing ulcerative gingivitis, compared to plaque-induced gingivitis [8].…”

“…The detection and counting of bacteria in the prepared samples was performed by FISH, followed by epifluorescence microscopy, in similar principles as previously described [8]. Briefly, 50 µl of 0.9% NaCl containing RNase inhibitor (Sigma Aldrich, Buchs, Switzerland) were added onto the pelleted sample, followed by shaking for 45 min, and vortexing for 1 min.…”

“…The slides were then incubated for 30 min at 37°C. Four specific oligonucleotide rRNA probes were used for Synergistetes cluster A and Synergistetes cluster B bacteria [6,8], a genus-specific probe for oral Fusobacteria [18], and a genus-specific probe for oral Actinomyces [19]. The cluster classification of oral Synergistetes bacteria into A and B was based on earlier studies [2,6,8].…”

“…paraformaldehyde at 4°C, washed with nanopure H 2 O and then processed for FISH analysis [8]. Every well was covered with 9 µl Denhardt's Solution (diluted 1:50 in PBS), including 1:500 RNase inhibitor, to reduce non-specific probe binding to the 7 bacterial cell wall.…”