This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vianna, M. E. Articles by Horz, H. P. Search for Related Content PubMed PubMed Citation Articles by Vianna, M. E. Articles by Horz, H. P.

Identification and Quantification of Archaea Involved in Primary Endodontic Infections

Endodontic Area, Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba SP, Brazil,¹ Division of Oral Microbiology and Immunology, Department of Operative and Preventive Dentistry and Periodontology, and Department of Medical Microbiology, RWTH University Hospital Aachen, Aachen, Germany²

Received 28 November 2005/ Returned for modification 4 January 2006/ Accepted 20 January 2006

Members of the domain Archaea, one of the three domains of life, are a highly diverse group of prokaryotes, distinct from bacteria and eukaryotes. Despite their abundance and ubiquity on earth, including their close association with humans, animals, and plants, so far no pathogenic archaea have been described. As some archaea live in close proximity to anaerobic bacteria, for instance, in the human gut system and in periodontal pockets, the aim of our study was to assess whether archaea might possibly be involved in human endodontic infections, which are commonly polymicrobial. We analyzed 20 necrotic uniradicular teeth with radiographic evidence of apical periodontitis and with no previous endodontic treatment. Using real-time quantitative PCR based on the functional gene mcrA (encoding the methyl coenzyme M reductase, specific to methanogenic archaea) and on archaeal 16S rRNA genes, we found five cases to be positive. Direct sequencing of PCR products from both genes showed that the archaeal community was dominated by a Methanobrevibacter oralis-like phylotype. The size of the archaeal population at the diseased sites ranged from 1.3 x 10⁵ to 6.8 x 10⁵ 16S rRNA gene target molecule numbers and accounted for up to 2.5% of the total prokaryotic community (i.e., bacteria plus archaea). Our findings show that archaea can be intimately connected with infectious diseases and thus support the hypothesis that members of the domain Archaea may have a role as human pathogens.

This article has been cited by other articles:

• Vianna, M. E., Holtgraewe, S., Seyfarth, I., Conrads, G., Horz, H. P. (2008). Quantitative Analysis of Three Hydrogenotrophic Microbial Groups, Methanogenic Archaea, Sulfate-Reducing Bacteria, and Acetogenic Bacteria, within Plaque Biofilms Associated with Human Periodontal Disease. J. Bacteriol. 190: 3779-3785 [Abstract] [Full Text]  
• Vickerman, M. M., Brossard, K. A., Funk, D. B., Jesionowski, A. M., Gill, S. R. (2007). Phylogenetic analysis of bacterial and archaeal species in symptomatic and asymptomatic endodontic infections. J Med Microbiol 56: 110-118 [Abstract] [Full Text]