Evaluation of Changes in Actin Filaments of RK13 Cells Infected with <i>Malassezia pachydermatis</i>

Abstract

Background: Malassezia pachydermatis is the main causative agent of canine otitis and also of a myriad of dermatological problems in companion animals; its interaction mechanisms with host cells are still unclear. Objectives: To establish an in vitro infection model of M. pachydermatis-exposed RK13 cells in order to evaluate cell morphological changes as well as changes in the structure of actin filaments. Methods: Cultures of RK13 cells were infected with M. pachydermatis, alterations caused by the yeast were evaluated by optical and fluorescence microscopy. Results: M. pachydermatis adheres itself to the cell and produces the formation of multiple agglomerates that cause changes in cell morphology, formation of cell aggregates in overlays, presence of syncytia and destruction of cell culture structure. The damaged cells presented changes in the actin filaments consisting of thickening of the cell cortex and loss of stress fibers. On the other hand, the formation of perinuclear actin rings in the yeasts was observed. Conclusions: An in vitro infection model was established with M. pachydermatis and alterations in cell morphology were observed consisting of changes in the structure of the actin filaments, overgrowth of the cells and the presence of syncytia.