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Streptococcal receptor polysaccharides: recognition molecules for oral biofilm formation.

Yoshida Y, Palmer RJ, Yang J, Kolenbrander PE, Cisar JO - BMC Oral Health (2006)

Bottom Line: Streptococcal gene clusters for RPS biosynthesis were identified, sequenced, characterized and compared.These motifs account for RPS-mediated recognition, whereas other features of these polysaccharides are more closely associated with RPS antigenicity.The structural, functional and molecular properties of streptococcal RPS support a recognition role of these cell surface molecules in oral biofilm formation.

View Article: PubMed Central - PubMed

Affiliation: Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA. yasuoy@iwate-med.ac.jp

ABSTRACT

Background: Strains of viridans group streptococci that initiate colonization of the human tooth surface typically coaggregate with each other and with Actinomyces naeslundii, another member of the developing biofilm community. These interactions generally involve adhesin-mediated recognition of streptococcal receptor polysaccharides (RPS). The objective of our studies is to understand the role of these polysaccharides in oral biofilm development.

Methods: Different structural types of RPS have been characterized by their reactions with specific antibodies and lectin-like adhesins. Streptococcal gene clusters for RPS biosynthesis were identified, sequenced, characterized and compared. RPS-producing bacteria were detected in biofilm samples using specific antibodies and gene probes.

Results: Six different types of RPS have been identified from representative viridans group streptococci that coaggregate with A. naeslundii. Each type is composed of a different hexa- or heptasaccharide repeating unit, the structures of which contain host-like motifs, either GalNAcbeta1-3Gal or Galbeta1-3GalNAc. These motifs account for RPS-mediated recognition, whereas other features of these polysaccharides are more closely associated with RPS antigenicity. The RPS-dependent interaction of S. oralis with A. naeslundii promotes growth of these bacteria and biofilm formation in flowing saliva. Type specific differences in RPS production have been noted among the resident streptococcal floras of different individuals, raising the possibility of RPS-based differences in the composition of oral biofilm communities.

Conclusion: The structural, functional and molecular properties of streptococcal RPS support a recognition role of these cell surface molecules in oral biofilm formation.

No MeSH data available.


Related in: MedlinePlus

RPS-mediated interbacterial adhesion promotes the growth of S. oralis 34 and A. naeslundii T14V as a biofilm in flowing human saliva. Flow cells were incubated overnight at 37C following inoculation with different combinations of wild type strain 34 or an RPS-negative mutant and wild type strain T14V or a type 2 fimbriae deficient mutant. Biofilms were labeled with conjugated antibodies to detect streptococci (red) and actinomyces (blue) and examined confocal fluorescent microscopy.
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Figure 4: RPS-mediated interbacterial adhesion promotes the growth of S. oralis 34 and A. naeslundii T14V as a biofilm in flowing human saliva. Flow cells were incubated overnight at 37C following inoculation with different combinations of wild type strain 34 or an RPS-negative mutant and wild type strain T14V or a type 2 fimbriae deficient mutant. Biofilms were labeled with conjugated antibodies to detect streptococci (red) and actinomyces (blue) and examined confocal fluorescent microscopy.

Mentions: The ecological role of RPS-mediated interbacterial adhesion may be to promote the formation of food chains and other mutualistic interactions that require close contact between different bacteria. Evidence for this possibility has been obtained using a flowcell model of biofilm formation in which human saliva is the sole source of nutrients for bacterial growth [22]. Biofilm formation was limited or did not occur under these conditions when either RPS-producing S. oralis 34 or type 2 fimbriated A. naeslundii T14V were introduced separately into flowcells. However, a luxuriant mixed-species biofilm formed when these two strains were introduced together. These observations have recently been extended by the results of similar experiments performed with these wild-type strains and corresponding mutant strains that specifically lack cell-surface RPS or type 2 fimbriae. As expected, wild-type S. oralis 34 and A. naeslundii T14V formed a luxuriant biofilm (Fig. 4). However, biofilm formation was greatly reduced when either wild-type strain was paired with the non-adherent mutant of the other cell type (i.e., RPS-negative S. oralis 34 or type 2 fimbriae-negative A. naeslundii T14V). Thus, RPS-mediated interbacterial adhesion appears to promote the establishment of a mutualistic association between S. oralis and A. naeslundii that is essential for luxuriant growth and mixed-species biofilm formation in flowing human saliva.


Streptococcal receptor polysaccharides: recognition molecules for oral biofilm formation.

Yoshida Y, Palmer RJ, Yang J, Kolenbrander PE, Cisar JO - BMC Oral Health (2006)

RPS-mediated interbacterial adhesion promotes the growth of S. oralis 34 and A. naeslundii T14V as a biofilm in flowing human saliva. Flow cells were incubated overnight at 37C following inoculation with different combinations of wild type strain 34 or an RPS-negative mutant and wild type strain T14V or a type 2 fimbriae deficient mutant. Biofilms were labeled with conjugated antibodies to detect streptococci (red) and actinomyces (blue) and examined confocal fluorescent microscopy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2147599&req=5

Figure 4: RPS-mediated interbacterial adhesion promotes the growth of S. oralis 34 and A. naeslundii T14V as a biofilm in flowing human saliva. Flow cells were incubated overnight at 37C following inoculation with different combinations of wild type strain 34 or an RPS-negative mutant and wild type strain T14V or a type 2 fimbriae deficient mutant. Biofilms were labeled with conjugated antibodies to detect streptococci (red) and actinomyces (blue) and examined confocal fluorescent microscopy.
Mentions: The ecological role of RPS-mediated interbacterial adhesion may be to promote the formation of food chains and other mutualistic interactions that require close contact between different bacteria. Evidence for this possibility has been obtained using a flowcell model of biofilm formation in which human saliva is the sole source of nutrients for bacterial growth [22]. Biofilm formation was limited or did not occur under these conditions when either RPS-producing S. oralis 34 or type 2 fimbriated A. naeslundii T14V were introduced separately into flowcells. However, a luxuriant mixed-species biofilm formed when these two strains were introduced together. These observations have recently been extended by the results of similar experiments performed with these wild-type strains and corresponding mutant strains that specifically lack cell-surface RPS or type 2 fimbriae. As expected, wild-type S. oralis 34 and A. naeslundii T14V formed a luxuriant biofilm (Fig. 4). However, biofilm formation was greatly reduced when either wild-type strain was paired with the non-adherent mutant of the other cell type (i.e., RPS-negative S. oralis 34 or type 2 fimbriae-negative A. naeslundii T14V). Thus, RPS-mediated interbacterial adhesion appears to promote the establishment of a mutualistic association between S. oralis and A. naeslundii that is essential for luxuriant growth and mixed-species biofilm formation in flowing human saliva.

Bottom Line: Streptococcal gene clusters for RPS biosynthesis were identified, sequenced, characterized and compared.These motifs account for RPS-mediated recognition, whereas other features of these polysaccharides are more closely associated with RPS antigenicity.The structural, functional and molecular properties of streptococcal RPS support a recognition role of these cell surface molecules in oral biofilm formation.

View Article: PubMed Central - PubMed

Affiliation: Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4352, USA. yasuoy@iwate-med.ac.jp

ABSTRACT

Background: Strains of viridans group streptococci that initiate colonization of the human tooth surface typically coaggregate with each other and with Actinomyces naeslundii, another member of the developing biofilm community. These interactions generally involve adhesin-mediated recognition of streptococcal receptor polysaccharides (RPS). The objective of our studies is to understand the role of these polysaccharides in oral biofilm development.

Methods: Different structural types of RPS have been characterized by their reactions with specific antibodies and lectin-like adhesins. Streptococcal gene clusters for RPS biosynthesis were identified, sequenced, characterized and compared. RPS-producing bacteria were detected in biofilm samples using specific antibodies and gene probes.

Results: Six different types of RPS have been identified from representative viridans group streptococci that coaggregate with A. naeslundii. Each type is composed of a different hexa- or heptasaccharide repeating unit, the structures of which contain host-like motifs, either GalNAcbeta1-3Gal or Galbeta1-3GalNAc. These motifs account for RPS-mediated recognition, whereas other features of these polysaccharides are more closely associated with RPS antigenicity. The RPS-dependent interaction of S. oralis with A. naeslundii promotes growth of these bacteria and biofilm formation in flowing saliva. Type specific differences in RPS production have been noted among the resident streptococcal floras of different individuals, raising the possibility of RPS-based differences in the composition of oral biofilm communities.

Conclusion: The structural, functional and molecular properties of streptococcal RPS support a recognition role of these cell surface molecules in oral biofilm formation.

No MeSH data available.


Related in: MedlinePlus