Corroding characteristics of Eikenella corrodens.

Fourteen strains of Eikenella corrodens isolated from human oral cavity were studied to determine corroding characteristics. Nine out of the 14 strains produced corroding colonies under anaerobic culture condition. One of them produced corrosion even in an aerobic culture. No morphological differences in surface structures were observed between corroding and non-corroding strains of E. corrodens by transmission electron microscopy. The morphology of corroding colonies of E. corrodens was then examined by scanning electron microscopy. The surface of the corroding-colony center was smoothly convex. A boundary line was clear between the smooth center and the surrounding corrosion region. Double or triple frill-like structures surrounded the center portion with small convexities. Spreading bacterial masses were observed in the outer portion of the colony. Morphological observations of the corroding colony edge indicated that a surface translocation termed "twitching motility" or "gliding motility" occurs in the outer portion and plays a role in its colonization of periodontal regions.

A heat stable hemagglutinating activity of Eikenella corrodens.

Strains of Eikenella corrodens and Fusobacterium nucleatum were shown to possess lectinlike attachment factors. The present investigators found that E. corrodens has a heat stable factor which agglutinates sheep, mouse, and human erythrocytes. The activity is not abolished by additions of galactose or lactose. Lipopolysaccharide preparations from E. corrodens strains possessed strong hemagglutinating activity. LPSs of F. nucleatum did not agglutinate any erythrocytes tested. SDS-PAGE patterns stained with silver stain revealed that the LPSs of E. corrodens strains were rough type and those of F. nucleatum were wild type. The heat stable hemagglutinating activity of E. corrodens strains might be caused the rough type LPS of the cells.