Clinical immunology Archaea prevalence in inflamed pulp tissues

Abstract

Archaea have been detected in several ecological niches of the human body such as the large intestine, skin, vagina as well as the oral cavity. At present, archaea are recognized as nonpathogenic microorganisms. However, some data indicate that they may be involved in the etiopathogenesis of several diseases, including intestinal diseases as well as oral diseases: periodontitis, peri-implantitis and endodontitis. In this study, on the basis of 16S rRNA gene sequence analysis, we examined whether archaea might be present in inflamed pulp tissues and contribute to the development of endodontic infection. In comparison, we also determined selected bacterial species associated with endodontitis. We detected archaea in 85% of infected endodontic samples. In addition, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola were present in inflamed pulp tissue samples and Treponema denticola occurred with the highest frequency (70%). Further analysis revealed the presence of methanogenic archaea in analyzed samples. Direct sequencing of archaeal 16S rRNA gene PCR products indicated the occurrence of methanogenic archaea in inflamed pulp tissues; phylogenetically most similar were Methanobrevibacter oralis and Methanobrevibacter smithii. Therefore, our results show that methanogenic archaea are present in inflamed pulp tissues and may participate in the development of endodontic infection.

Emerging facets of prokaryotic glycosylation

“…DNA from root canals of one of these patients showed also the presence of ‘red complex bacteria’ (Holt and Ebersole 2005). These results confirm the presence of archaea in root canals and provide additional insights into the polymicrobial communities in endodontic infections associated with clinical symptoms (Mansfield et al 2012; Efenberger et al 2015). Among this group of ‘red complex bacteria’ is also Tannerella forsythia , whose glycosylated S-layer proteins TfsA and TfsB have been characterised recently (Posch et al 2011) ( vide supra and Fig.…”

Comparison of Oral Microbe Quantities from Tongue Samples and Subgingival Pockets

“…Members of the Archaea also colonize the oral cavity, especially within subgingival plaques and on tooth surfaces [ 21 , 36 – 38 ], while the diversity seems to be very narrow. We detected archaeal sequences in 73.0% of tongue samples, but only 16.9% of subgingival pocket samples.…”

Methanosphaera stadtmanae induces a type IV hypersensitivity response in a mouse model of airway inflammation

“…This study demonstrated that archaeal crude extracts induce the recruitment of CD4 + and CD19 + cells in the lung along with a strong production of serum IgG (Blais-Lecours et al 2011). Importantly, human endogenous viable methanogens species are associated with oral diseases (Lepp et al 2004;Vianna et al 2006Vianna et al , 2008Vianna et al , 2009Vickerman et al 2007;Jiang et al 2009;Efenberger et al 2015), intestinal diseases (Scanlan et al 2008;Lee et al 2013;Blais-Lecours et al 2014;Mira-Pascual et al 2015) and obesity (Zhang et al 2009;Mbakwa et al 2015). Methanogens activate human peripheral blood cells to release the important immune mediator TNF (Blais-Lecours et al 2014), and methanogen-specific IgGs are detectable in periodontic and inflammatory bowel disease (IBD) patients, documenting their potential as activators of the human immune system in environments where the strict methanogen conditions allow their survival.…”