Critical Reviews in Oral Biology & Medicine, Vol 8, 175-200, Copyright © 1997 by International & American Associations for Dental Research
Streptococcal adhesion and colonization
H. F. Jenkinson and R. J. Lamont
Department of Oral Biology and Oral Pathology, University of Otago, Dunedin, New Zealand.
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.
