FACTORS AFFECTING THE ADHERENCE OF MALASSEZIA-PACHYDERMATIS TO CANINECORNEOCYTES IN-VITRO

Suspensions of Malassezia pachydermatis adhered to canine corneocytes attached to adhesive tape in a dose (P<0.001) and time-dependent (P<0. 01) manner; adherence was maximal after 2 h. M. pachydermatis cells we re approximately 10 times more adherent than Saccharomyces cerevisiae (P<0.001) cells after 2 h incubation. The adherence of formalin-treate d and frozen-thawed M. pachydermatis cells was comparable with untreat ed controls. Stationary-phase cells adhered better (P<0.05) than expon ential-phase cells. Pretreatment of the yeasts, or corneocytes, with 0 .1% trypsin for 30 min reduced (P<0.01) the adherence of four, and two , out of five strains, respectively, whereas incubation with 300 mM so lutions of D(+) mannose, sucrose and N-acetyl D-glucosamine had no con sistent effect. These results suggest that trypsin-sensitive proteins or glycoproteins on the yeast cell wall, and on the corneocyte surface , play an important role in the adherence of M. pachydermatis to canin e corneocytes in vitro, whereas a role for carbohydrate receptors was not demonstrated.