Distribution ofArchaeain Japanese patients with periodontitis and humoral immune response to the components

Abstract

There is controversy regarding the existence of archaeal pathogens. Periodontitis is one of the human diseases in which Archaea have been suggested to have roles as pathogens. This study was performed to investigate the distribution of Archaea in Japanese patients with periodontitis and to examine the serum IgG responses to archaeal components. Subgingival plaque samples were collected from 111 periodontal pockets of 49 patients (17 with aggressive periodontitis and 32 with chronic periodontitis), and 30 subgingival plaque samples were collected from 17 healthy subjects. By PCR targeting the 16S rRNA gene, Archaea were detected in 15 plaque samples (13.5% of total samples) from 11 patients (29.4% of patients with aggressive periodontitis and 18.8% of patients with chronic periodontitis). Archaea were detected mostly (14/15) in severe diseased sites (pocket depth > or =6 mm), while no amplicons were observed in any samples from healthy controls. Sequence analysis of the PCR products revealed that the majority of Archaea in periodontal pockets were a Methanobrevibacter oralis-like phylotype. Western immunoblotting detected IgG antibodies against M. oralis in eight of the 11 sera from patients. These results suggest the potential of Archaea (M. oralis) as an antigenic pathogen of periodontitis.

Real-Time PCR Quantification of Methanobrevibacter oralis in Periodontitis

“…Total bacterial control indicated that for a C T value of Ͼ35.5, M. oralis detection was not interpretable. Based on these controls, the detection of M. oralis DNA in healthy individuals (C T Յ 35.5) was possible, in contrast to findings of previous studies (12,13,17,18), and a significant correlation was observed between the M. oralis load and periodontitis severity.…”

“…PCR systems previously used to detect methanogens in the subgingival plaque (6,8,12,13) were not completely specific for M. oralis. Indeed, other methanogens, including Methanobrevibacter smithii (14), Methanosphaera stadtmanae (6), Methanobacterium curvum/Methanobacterium congolense, and Methano-sarcina mazeii (15,16), have been detected in this situation.…”

“…The M. oralis cell number correlated significantly with the periodontal clinical score, with an r value of 0.527 (n ϭ 30) and a P value of 0.003. The significance, analysis of variance (ANOVA) test, or the Kruskal-Wallis test (2-tailed) correlation was 0.003.PCR systems previously used to detect methanogens in the subgingival plaque (6,8,12,13) were not completely specific for M. oralis. Indeed, other methanogens, including Methanobrevibacter smithii (14), Methanosphaera stadtmanae (6), Methanobacterium curvum/Methanobacterium congolense, and Methano-…”

Reduction in prevalence ofArchaeaafter periodontal therapy in subjects with generalized aggressive periodontitis

“…periodontal disease. 20 Sixteen studies were selected [8][9][10][11][12][13][14][15]23,[26][27][28][29][30][31] and Methanobrevibacter, Methanosphaera, Methanosarcina, Thermoplasmata and Methanobacterium were considered the five most common genera of methanogenic Archaea present in the subgingival biofilm. In addition, the pooled prevalence of these studies showed that M. oralis was detected in 41% of the periodontitis subjects in comparison with only 6% of the periodontally healthy subjects (p < 0.05).…”

“…4,5 Furthermore, recent studies have implicated microorganisms other than bacteria with the aetiology of periodontitis, such as certain viruses 6,7 and species from the Archaea domain. [8][9][10][11][12][13][14][15] Archaea are a group of single-cell microorganisms that were classified, based on the sequence of ribosomal RNA genes, as a distinct group of organisms, differing greatly from Bacteria and Eukaryotes 16 in terms of genetic, biochemical, and structural features. 17,18 Several studies have shown that Archaea can be isolated from subgingival samples of periodontitis patients, 10,[12][13][14][15]19,20 infected root canals, 21,22 and in sites with peri-implantitis.…”