Table of Contents
Volume 2010, Article ID 457236, 6 pages
Research Article

Complete Genome Sequence of Rothia mucilaginosa DY-18: A Clinical Isolate with Dense Meshwork-Like Structures from a Persistent Apical Periodontitis Lesion

1Department of Bacteriology, Osaka Dental University, 8-1 Kuzuhahanazono-cho, Hirakata-shi, Osaka 573-1121, Japan
2Microbiology Branch, U.S. Army Dental and Trauma Research Detachment, Walter Reed Army Institute of Research, Great Lakes, IL 60088, USA

Received 3 June 2010; Revised 26 August 2010; Accepted 25 September 2010

Academic Editor: Fengfeng Zhou

Copyright © 2010 Kazuyoshi Yamane et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Rothia mucilaginosa is an opportunistic pathogen in the human oral cavity and pharynx. We found that R. mucilaginosa DY-18, a clinical isolate from a persistent apical periodontitis lesion, had biofilm-like structures. Similar structures were also observed on R. mucilaginosa ATCC25296. To further study these structures, we determined the complete genome sequence of DY-18 and found it a 2.26-Mb chromosome. Regarding stress responsive systems known to affect biofilm formation in many bacteria, DY-18 genome possessed only two sigma factor genes. One of these encoded an additional sigma factor whose promoter-binding activity may be regulated in response to environmental stimuli. Additionally, several genes assigned to two-component signal transduction systems were presented in this genome. To the best of our knowledge, this is the first complete genome of R. mucilaginosa species and our data raise the possibility that this organism regulates the biofilm phenotype through these stress responsive systems.