Capsule of S. Aureus: Bone Tropism, Adherence and Host Immunity (Rat Model)

摘要

Staphylococcus aureus binding to exposed collagen may enhance infection incertain tissues, e.g., long bone. Clinical isolates of s. aureus from a variety of infections and colonization sites were assessed for their ability to bind type I collagen. In addition, the ability of a single pathogen, isolated from human osteomyelitic bone, to bind collagen was studied in detail. An attempt was made to discern the nature of ligands, in bone, bound by cells of the bone pathogen. To do this, an isogenic mutant with a reduced ability to bind type I collagen was created using transposon mutagenesis. In DNA analysis, the mutant had Tn551 inserted into its chromosomal DNA. Conversely, cells of the parent strain were nonreactive for transposon. Using comparative analysis of SDS-PAGE profiles of adsorbed bacteria, exposed to isolated bone-matrix proteins, it was shown that collagen a1-chains were bound preferentially by parent cells. The mutant had approximately one-third the affinity of the parent for type I collagen. This approach to studies of staphylococcal tissue-tropism, via specific adherence, may improve our understanding of how bone infections are initiated by this important pathogen.