Genetic transformation of putative cariogenic properties in Streptococcus mutans

Bacteria produce several peptidoglycan hydrolases (PGHs). There are at least five types of PGHs: endo-β-N-acetylglucosaminidase, endo-β-N-acetylmuraminidase, N-acetylmuramyl-L-alanine-amidase, endopeptidase and transglycosylase; each known for the specific bond they split in the cell wall (1,19). They are ubiquitous in bacteria and show functions in restructuring the cell wall where they have many important roles in cell wall metabolism including nicking peptidoglycan for insertion of a new peptidoglycan monomer, cell division, cell separation, and cell wall turnover (1,19,26). Many PGHs are termed bacteriolytic because the action of the enzyme often leads to bacterial cell lysis. Some enzymes are able to disintegrate their own peptidoglycan saccules when the cells are placed in unfavorable conditions; and such enzymes are called autolysins.Streptococci are Gram-positive bacteria where individual cells are connected with each other forming a chain morphology. Among the streptococci, S. pneumoniae, the leading cause of pneumonia, blood stream infections and otitis media, is the most extensively studied concerning the biochemistry and physiological functions of the PGHs. S. pneumoniae produces at least three types of PGHs: LytA amidase (16), LytB endo-β-N-acetylglucosaminidase (4, 7) and LytC lysozyme (6). Their roles in cell separation and viru-

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“…Routine DNA manipulations were performed using standard procedures. Transformation of S. mutans was performed as described previously (20).…”

Section: Methodsmentioning

confidence: 99%

Identification and Molecular Characterization of an N‐Acetylmuraminidase, Aml, Involved in Streptococcus mutans Cell Separation

Yoshimura

Komatsuzawa

Hayashi

et al. 2006

Microbiology and Immunology

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“…The construct was confirmed by sequencing. Natural transformation of S. mutans cells was performed (Perry et al, 1983) and the selected transformants were confirmed by PCR and direct sequencing.…”

Section: Plasmid Complementationmentioning

confidence: 99%

Identification and characterization of an autolysin gene,atlg, fromStreptococcus sobrinus

Yamada

Tamura

Kato

2009

FEMS Microbiology Letters

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AtlA is a major cell-lytic enzyme called autolysin in Streptococcus mutans. In this study, we identified the atlg gene-encoding autolysin (Atlg), consisting of 863 residues from Streptococcus sobrinus 6715DP, and confirmed lytic activity of recombinant Atlg by zymography of S. sobrinus cells. An atlA-inactivated mutant was constructed in S. mutans Xc, and the atlg gene product was characterized by plasmid complementation. Microscopic analysis, saliva-induced aggregation assay and autolysis assay of static cultures in air revealed that the atlg gene product partially complemented the role of AtlA. Furthermore, the capability of biofilm formation of the atlA-deficient mutant cultivated in air was restored by plasmid comprising the atlg gene. These findings suggest that Atlg may be involved in cell separation and biofilm formation in S. sobrinus.

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“…Transformation of S. mutans was performed as previously reported by Perry et al (1983). PS-ODNs were added to the competent cultures respectively.…”

Section: Transformation Of S Mutansmentioning

confidence: 99%

Treatment ofStreptococcus mutanswith antisense oligodeoxyribonucleotides togtfBmRNA inhibits GtfB expression and function

Guo

Gang

et al. 2006

FEMS Microbiology Letters

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We examined the effects of phosphorothioate-modified antisense oligodeoxyribonucleotides (PS-ODN) targeted to mRNA transcribed from gtfB, which encodes synthesis of water-insoluble glucans in Streptococcus mutans. Treatment of S. mutans with 10 muM antisense PS-ODNs inhibited gtfB mRNA transcription, GtfB expression and water-insoluble glucan synthesis. The architecture of biofilms formed by antisense PS-ODNs-treated S. mutans showed reduced biomass, more dispersed distribution with enlarged interspaces and fewer layers of attached cells. PS-ODN treatment had no effect on the growth of S. mutans. Our results indicated that it might be feasible to use antisense PS-ODN as a novel agent in caries prevention.

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Genetic transformation of putative cariogenic properties in Streptococcus mutans

Cited by 88 publications

References 15 publications

Identification and Molecular Characterization of an N‐Acetylmuraminidase, Aml, Involved in Streptococcus mutans Cell Separation

Identification and Molecular Characterization of an N‐Acetylmuraminidase, Aml, Involved in Streptococcus mutans Cell Separation

Identification and characterization of an autolysin gene,atlg, fromStreptococcus sobrinus

Treatment ofStreptococcus mutanswith antisense oligodeoxyribonucleotides togtfBmRNA inhibits GtfB expression and function

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