Identification of the surface component of Streptococcus defectivus that mediates extracellular matrix adherence.
Bacterial attachment to host tissue is considered to be a crucial primary step in pathogen infection. Previous studies have shown that Streptococcus defectivus adheres specifically to cell-secreted extracellular matrix (ECM). Though generally not exposed in vivo, this host tissue is exposed at endothelial cell junctions and sites of tissue injury. In this report, we identify a ca. 200-kDa surface protein of S. defectivus involved in ECM adherence. Nitrous acid-derived mutant strains that were unable to bind ECM and which failed to adsorb adhesin-specific antibody from polyclonal inhibitory sera were isolated. A surface protein (ca. 200 kDa) was absent from ECM-nonadherent mutants, indicating its involvement in ECM attachment. Additionally, affinity-purified antibody to the ca. 200-kDa protein inhibited whole-cell S. defectivus ECM attachment, whereas antibody to the same region of the nonadherent mutant cell wall-associated protein profile did not. Furthermore, solubilized cell wall-associated protein extracts of parent but not mutant strains bound ECM, confirming the significance of this protein in ECM adherence. Therefore, we propose that the ca. 200-kDa protein is the major S. defectivus surface component that mediates the ECM attachment of these organisms.
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Wake Forest University Medical Center, Winston-Salem, North Carolina 27157-1064.
van de Rijn
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D018829:Adhesins, Bacterial; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology / Q000502:physiology*; D002478:Cells, Cultured; D006224:Cricetinae; D005109:Extracellular Matrix / Q000502:physiology*; D066298:In Vitro Techniques; D008970:Molecular Weight; D009154:Mutation; D013291:Streptococcus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*
D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins