Streptococcal Adhesion and Colonization

Abstract

Streptococci express arrays of adhesins on their cell surfaces that facilitate adherence to substrates present in their natural environment within the mammalian host. A consequence of such promiscuous binding ability is that streptococcal cells may adhere simultaneously to a spectrum of substrates, including salivary glycoproteins, extracellular matrix and serum components, host cells, and other microbial cells. The multiplicity of streptococcal adherence interactions accounts, at least in part, for their success in colonizing the oral and epithelial surfaces of humans. Adhesion facilitates colonization and may be a precursor to tissue invasion and immune modulation, events that presage the development of disease. Many of the streptococcal adhesins and virulence-related factors are cell-wall-associated proteins containing repeated sequence blocks of amino acids. Linear sequences, both within the blocks and within non-repetitive regions of the proteins, have been implicated in substrate binding. Sequences and functions of these proteins among the streptococci have become assorted through gene duplication and horizontal transfer between bacterial populations. Several adhesins identified and characterized through in vitro binding assays have been analyzed for in vivo expression and function by means of animal models used for colonization and virulence. Information on the molecular structure of adhesins as related to their in vivo function will allow for the rational design of novel acellular vaccines, recombinant antibodies, and adhesion agonists for the future control or prevention of streptococcal colonization and streptococcal diseases.

Biofilm exopolysaccharides: a strong and sticky framework

“…The poorly water-soluble α--glucans are first secreted and attach to the oral surfaces. Subsequently, oral streptococci can bind to these (Jenkinson & Lamont, 1997). The glucans thus act as intramolecular bridges.…”

Salivary IgA enhancement strategy for development of a nasal-spray anti-caries mucosal vaccine

“…Thereafter, various cell-surface antigens of mutans streptococci and their recombinant fragments or even synthetic peptides have been studied as possible candidates for dental caries vaccines [28,29]. In the recent decade, attention has become focused on three protein antigens: the surface fibrillar adhesins, the glucosyltransferases (GTF) and the glucan-binding proteins, all of which have demonstrable associations with virulence and the process of tooth surface colonization [8,12,[30][31][32]. It is demonstrated that the streptococcal surface fibrillar adhesins control attachment to tooth surfaces, the glucosyltransferases produce adhesive glucans from sucrose, and the cell-wall-associated glucan-binding proteins have the ability to bind α-1,6-glucan and may provide the receptors for glucan-mediated aggregation [33].…”

Salivary MUC5B-Mediated Adherence (Ex Vivo) of Helicobacter pylori During Acute Stress

“…However, the functions of saliva are not limited to the protection of the oral cavity because the mouth also serves as a reservoir and portal of entry for microorganisms that are active elsewhere in the body. These include several Streptococcus species (18), Hemophilus influenzae (19), Epstein-Barr virus, and her-pes simplex virus (20). Here, the role of saliva is not necessarily a protective one.…”