Attachment of Malassezia pachydermatis to the ear dermal gels in canine otitis externa

TO investigate the predominance of Malassezia pachydermatis (M. pachydermat is) as a causative agent of canine otitis externa, ear cerumen samples were observed for adhesion of M. pachydermatis to the cornified epithelial cell s by light and electron microscopes. The yeasts appeared not to adhere to t he cornified epithelial cells directly, but they seemed to exist in the pro ximity of the epithelial cells with an electron opaque halo-like space arou nd them. Polysaccharide and lipid staining techniques were conducted to ide ntify the substances existing in that space. Lipid substances, not sacchari des, were observed around the yeasts and the cornified epithelial cells. Th ese results suggested that in the canine ear canal malassezia yeast attachm ent to the cornified epithelial cells is mediated by lipids.