Selective adherence of Erysipelothrix rhusiopathiae to heart valves of swine investigated in an in vitro test.

An in vitro test for the adherence of microorganisms to epithelial surfaces was performed in an attempt to illustrate the initial steps in the establishment of infectious endocarditis. Preparations of fresh heart valves of swine were incubated in suspensions of Erysipelothrix rhusiopathiae. There was a significant difference (P < 0.01) in the degree of adherence between the 5 strains of E. rhusiopathiae investigated. The highest degree of adherence was found in an isolate from an endocardial vegetation and in a strain labelled type A1, both originating from swine. Scanning electron microscopy showed the microorganisms distributed on the endocardial surface and in large numbers at the base of the chordae tendinae.