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Abstract
Streptococcus mutans, a principal causative agent of dental caries, is considered to be the most cariogenic among all oral streptococci. Of the four S. mutans serotypes (c, e, f, and k), serotype c strains predominate in the oral cavity. Here, we present the complete genome sequence of S. mutans GS-5, a serotype c strain originally isolated from human carious lesions, which is extensively used as a laboratory strain worldwide.
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Huang WC, Chen YYM, Teng LJ, Lien HT, Chen JY, Chia JS. Chromosomal inversion between rrn operons among Streptococcus mutans serotype c oral and blood isolates. J Med Microbiol 2008; 57:198-206. [PMID: 18201986 DOI: 10.1099/jmm.0.47428-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Streptococcus mutans causes dental caries and infective endocarditis. The aim of this study was to determine genomic diversity among serotype c S. mutans laboratory and clinical strains and to characterize the genetic events involved. A genome-based approach using PFGE coupled with Southern hybridization was employed to examine a total of 58 serotype c oral and blood isolates and seven laboratory strains and to compare them with S. mutans UA159. No significant differences were found in the phenotypic characteristics of the strains tested, except that some of the strains exhibited smooth rather than rough colony morphology. In contrast, PFGE profiles of clinical isolates, from either diseased or healthy subjects, exhibited diverse patterns, suggesting that recombination or point mutations occurred frequently in vivo. Diverse PFGE patterns, with various lengths of insertions and deletions, could be detected even within a localized chromosomal region between rRNA operons. Comparative analysis using Southern hybridization with specific markers revealed that a large chromosomal inversion had also occurred between rrn operons in 25 strains.
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Affiliation(s)
- Wen-Chuan Huang
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC
| | - Yi-Ywan M Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taipei, Taiwan, ROC
| | - Lee-Jene Teng
- Department of Clinical Laboratory Sciences and Medical Biotechnology, Taipei, Taiwan, ROC
| | - Huwei-Ting Lien
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC
| | - Jen-Yang Chen
- National Health Research Institute, Taipei, Taiwan, ROC.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC
| | - Jean-San Chia
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan, ROC.,Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC
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Waterhouse JC, Russell RRB. Dispensable genes and foreign DNA in Streptococcus mutans. MICROBIOLOGY-SGM 2006; 152:1777-1788. [PMID: 16735740 DOI: 10.1099/mic.0.28647-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A range of properties, including the ability to utilize various sugars, bind macromolecules and produce mutacins, are known to vary in their occurrence in different strains of Streptococcus mutans. In addition, insertion-sequence elements show a limited distribution and sequencing of the genome of S. mutans UA159 has revealed the presence of putative genomic islands of atypical base composition indicative of foreign DNA. PCR primers flanking regions suspected of having inserted DNA were designed on the basis of the genome sequence of S. mutans UA159 and used to explore variation in a collection of 39 strains isolated in various parts of the world over the last 40 years. Extensive differences between strains were detected, and similar insertion/deletion events appear to be present in the genomes of strains with very different origins. In two instances, insertion of foreign DNA appears to have displaced original S. mutans genes. Together with previous results on the occurrence of deletions in genes associated with sugar metabolism, the results indicate that S. mutans has a core genome and a dispensable genome, and that dispensable genes have become widely distributed through horizontal transfer.
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Affiliation(s)
- Janet C Waterhouse
- Oral Biology, School of Dental Sciences, University of Newcastle, Newcastle upon Tyne NE2 4BW, UK
| | - Roy R B Russell
- Oral Biology, School of Dental Sciences, University of Newcastle, Newcastle upon Tyne NE2 4BW, UK
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Yamamoto Y, Sato Y, Takahashi-Abbe S, Takahashi N, Kizaki H. Characterization of the Streptococcus mutans pyruvate formate-lyase (PFL)-activating enzyme gene by complementary reconstitution of the In vitro PFL-reactivating system. Infect Immun 2000; 68:4773-7. [PMID: 10899886 PMCID: PMC98435 DOI: 10.1128/iai.68.8.4773-4777.2000] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The act gene was identified and an act mutant as well as the pfl mutant was constructed in Streptococcus mutans. Pyruvate formate-lyase (PFL) activity was regenerated with the mixture of the respective cell extracts from these mutants by complementary reconstitution of the in vitro reactivating system. The S. mutans act gene encoded the sole enzyme able to activate the PFL protein in this organism.
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Affiliation(s)
- Y Yamamoto
- Department of Biochemistry, Tokyo Dental College, Mihama-ku, Chiba City 261-8502, Japan.
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