title: Genotyping and characterisation of the secretory lipolytic enzymes of Malassezia pachydermatis isolates collected from dogs.
abstract: BACKGROUND
  Malassezia species are commensals of normal skin microbial flora of humans and animals. These may become pathogenic under certain conditions such as those associated with atopic dermatitis or otitis externa in dogs.
  
  
  METHODS
  Isolates of Malassezia pachydermatis were obtained from 27 dogs with healthy external ears and 32 dogs with otitis externa. Isolates were characterised on the basis of their first internal transcribed spacer (ITS) and internal spacer 1 (IGS1) sequences. Their extracellular lipase and phospholipase activity were also analysed. Three types of phospholipase inhibitor were used to identify the subclasses of phospholipase associated with otitis externa.
  
  
  RESULTS
  The clinical isolates were classified into three ITS and three IGS1 sequence types. No significant differences in pathogenicity were detected among the ITS or IGS1 genotypes, and all of the isolates exhibited similar levels of lipase activity. The isolates derived from the dogs with otitis externa showed significantly higher phospholipase activity than those obtained from the dogs with healthy external ears. A phospholipase D inhibitor reduced the phospholipase activity of the isolates obtained from the dogs with otitis externa.
  
  
  CONCLUSIONS
  This study did not show any significant differences in pathogenicity among the ITS or IGS1 genotypes but does suggest that phospholipase D might be one of the virulence factors involved in the inflammation of the external ear caused by M. pachydermatis.
authors.affiliation: Shinchitose Animal Clinic , Hokkaido , Japan ; Department of Veterinary Science , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Teramoto
authors.affiliation: Osaka Prefectural Institute of Public Health , Osaka , Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kumeda
authors.affiliation: Faculty of Integrated Arts and Sciences, Department of Civil and Environmental Studies , University of Tokushima , Tokushima , Japan.
authors.forename: Kumio
authors.initials: K
authors.lastname: Yokoigawa
authors.affiliation: Department of Veterinary Science , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Hosomi
authors.affiliation: Department of Veterinary Science , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Kozaki
authors.affiliation: Department of Veterinary Science , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Mukamoto
authors.affiliation: Department of Veterinary Science , Graduate School of Life and Environmental Sciences, Osaka Prefecture University , Osaka , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kohda
keywords: Bacterial pathogenesis; Malassezia; Otitis media; Zoonoses