Identification of archaeal rDNA from subgingival dental plaque by PCR amplification and sequence analysis

Abstract

A PCR assay for the amplification of small subunit ribosomal DNA (SSU rDNA) of Euryarchaea was developed and used to detect archaeal rDNA in 37 (77%) out of 48 pooled subgingival plaque samples from 48 patients suffering from periodontal disease. One major group of cloned periodontal sequences was identical to Methanobrevibacter oralis and a second minor group to Methanobrevibacter smithii. These two groups and a third novel group were found to be more than 98% similar to each other over an 0.65-kb segment of the 16S rRNA gene sequenced. M. oralis was found to be the predominant archaeon in the subgingival dental plaque. Phylogenetic analysis of partial SSU rDNA sequences revealed evidence for a distinct cluster for human and animal Methanobrevibacter sp. within the Methanobacteriaceae family. ß

Rapid start-up of thermophilic anaerobic digestion with the turf fraction of MSW as inoculum

“…The spike addition of additional acetate (Fig 5B, day 15 Although methanogens have been found in various environments such as human dental plaque (Kulik et al, 2001), and rice paddy (Watanabe et al, 2006), the current study shows the first evidence of the systematic presence of thermophilic methanogens in grass lawn. To explain this finding, further study is required addressing questions such as below:…”

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

“…The high prevalence of Archaea observed in these subjects is in agreement with results from previous studies from our and other groups of investigators. 10,12,15,23 The role of Archaea in the aetiology of periodontal disease remains controversial. A recent systematic review provided interesting data about the relationship between presence of methanogenic Archaea in the subgingival biofilm and The significance of differences between time points was assessed using the Wilcoxon test (different small letters indicate p < 0.05).…”

“…The 16S rRNA was amplified under standardized conditions using a universal primer pair (forward primer 300fEyAr5'-AGCRRGAGCCCGGAGATGG3'; reverse primer 954rEyAr 5'-7 CGGCGTTGARTC-CAATTAAAC-3') as described by Kulik et al 10 The primers were commercially synthesized (Invitrogen, São Paulo, Brazil). PCR was performed in thin-walled tubes with Peltier Thermal Cycles PTC-200 (MJ Research Inc.; Watertown, MA, USA).…”

“…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.…”

Microbial Biofilm Formation as a Dental-fouling Microorganisms Attachment Phenomenon in Oral Cavity Environment

“…Oral microbes are predominantly bacteria but fungi, viruses, mycoplasmas and even protozoa and archaea can also be found [3,5]. Dental plaque can be defined as the diverse community of microorganisms found on the tooth surface as a biofilm, embedded in an extracelluar matrix of polymers of host and microbial origin [6].…”