Role of a cell surface-associated protein in adherence and dental caries

Abstract

Insertional inactivation of the Streptococcus mutans spaP gene was used to construct an isogenic mutant (834) of strain NG8 (serotype c) which lacked the major cell surface-associated protein referred to as P1 (15). Results of several studies suggest that P1 is involved in the adherence of S. mutans to saliva-coated apatite surfaces. With an in vitro model system of hydroxyapatite (HA) beads coated with parotid saliva (PS) and additional HA surfaces coated with PS and in situ-formed glucan, it was observed that mutant 834 adhered poorly to the PS/HA surfaces. In contrast, both parent and mutant strains bound to the PS-glucan/HA surtace. Groups of intact and desalivated rats were infected with each strain to determine relative capacities to induce dental caries. Rats were fed a highly cariogenic diet containing 56% sucrose for 3 to 5 weeks. Each strain colonized the rodent model and caused similar levels of smooth-surface caries under these dietary conditions. It was concluded that P1 influences the ability of organisms to adhere to saliva-coated surfaces and poNsibly affects primary colonization of the oral cavity in the absence of a glucan surface but has no effect on glucan-mediated adherence in vitro or in vivo.

Transcriptome analysis of LuxS‐deficient Streptococcus mutans grown in biofilms

“…In addition, the fact that the luxS mutant did not adhere well to the glass slides in the absence of sucrose, and formed fewer microcolonies than the wild-type, suggests that defects in initial adherence may be part of the reason the TW26D strain shows diminished biofilm forming capacity. In the absence of sucrose, SpaP (also called P1), a multi-functional adhesin that interacts with salivary agglutinin, is considered a major factor in S. mutans adherence and biofilm initiation on the tooth surface (Bowen et al, 1991;Crowley et al, 1999). Although no significant differences were identified in sessile populations between the wild-type and the LuxSdeficient mutant, real-time PCR analysis with total RNA extracted from planktonic cultures grown on BHI revealed that the expression of spaP was downregulated by more than threefold in response to LuxSdeficiency (Table 3), which is consistent with recent findings of Merritt et al (2005).…”

The Pst system of Streptococcus mutans is important for phosphate transport and adhesion to abiotic surfaces

“…The initial reversible and sucrose-independent stage promotes binding of bacteria to the tooth surface using electrostatic charges and hydrophobic interactions of surface components, followed by the action of specific adhesins that recognize saliva components bound to the tooth surface (Burne, 1998). The second and irreversible sucrose-dependent stage involves production of insoluble polysaccharides that contribute both to adhesion to the tooth surface and the formation of the complex biofilm structures (Hamada et al, 1984;Bowen et al, 1991;Crowley et al, 1999). Here we showed that deletion of the pstS gene affects binding of S. mutans to saliva-coated surfaces in cells cultivated in the presence of sucrose.…”

“…Streptococcus mutans is the major etiological agent of human dental caries (Bowen et al, 1991). Tooth decay caused by S. mutans is the result of two sets of bacterial traits: adhesion to the tooth surface, followed by the subsequent formation of structurally complex biofilms and production of acid (acidogenicity) concomitant with the ability to survive and replicate in acidic environments (aciduricity) (Burne, 1998).…”

“…Tooth decay caused by S. mutans is the result of two sets of bacterial traits: adhesion to the tooth surface, followed by the subsequent formation of structurally complex biofilms and production of acid (acidogenicity) concomitant with the ability to survive and replicate in acidic environments (aciduricity) (Burne, 1998). Biofilm formation by S. mutans is a limiting factor in the process of tooth cavity formation and involves an initial reversible sucrose-independent stage and a subsequent irreversible sucrose-dependent stage (Hamada et al, 1984;Bowen et al, 1991;Burne, 1998;Crowley et al, 1999).…”

Streptococcus pyogenes antigen I/II‐family polypeptide AspA shows differential ligand‐binding properties and mediates biofilm formation

“…The AgI/II-family polypeptides are cell wall-anchored and comprise between 1310 and 1653 amino acid (aa) residues (Brady et al, 2010). The SpaP (AgI/II-family) protein in Streptococcus mutans mediates adherence to salivary glycoproteins within the tooth enamel pellicle (Bowen et al, 1991). Antibodies to SpaP block adherence of S. mutans (Munro et al, 1993), and a peptide vaccine derived from SpaP has been shown to protect rodents against dental decay caused by S. mutans (Takahashi et al, 1991).…”