title: [Phospholipase and proteinase production by Malassezia pachydermatis isolated in dogs with and without otitis].
abstract: BACKGROUND
  Malassezia pachydermatis is part of the skin microbiota of dogs and cats. M. pachydermatis has been associated with external otitis and seborrhoeic dermatitis, reported more often in dogs than in cats. When the physical, chemical or immunological mechanisms of the skin are altered, M. pachydermatis could act as a pathogen. Thus, several virulence factors, such as the ability to produce esterase, lipase, lipoxygenase, protease, chondroitin sulphatase, and hyaluronidase, have been studied.
  
  
  OBJECTIVE
  In the present study, we aim to identify the phospholipase activity measured at pH 6.3, and the proteinase activity measured at pH 6.3 and pH 6.8 (pH from ears of dogs with external otitis) of M. pachydermatis strains isolated from dogs with and without external otitis.
  
  
  METHODS
  The phospholipase activity was measured using a semi-quantitative method with egg yolk, and the proteinase activity with a semi-quantitative method using bovine serum albumin agar. The study was performed on 96 isolates of M. pachydermatis, 43 isolated from dogs without clinical symptoms of otitis, and 52 isolated from dogs with otitis.
  
  
  RESULTS
  In our study, 75.8% of the isolates showed phospholipase activity at pH 6.3, and 81 and 97.9% of them showed proteinase activity measured at pH 6.3 and 6.8, respectively. A higher phospholipase activity was detected in strains isolated from dogs with otitis. The proteinase activity was increased at a pH of 6.8 (97.9%) in comparison to a pH of 6.3 (81%).
  
  
  CONCLUSIONS
  Our results suggest that the phospholipase activity may play an important role in the invasion of host tissues in chronic canine otitis cases. The proteinase activity results obtained in this study suggest that a reduction in the pH of the treatment may improve its efficacy in the resolution of M. pachydermatis otitis.
authors: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, España; Hospital Clínico Veterinario, Universidad Alfonso X el Sabio, Villanueva de la Cañada, Madrid, España. Electronic address: gortidie@uax.es.
authors: Gustavo
authors: G
authors: Ortiz
authors: M Carmen
authors: MC
authors: Martín
authors: Alfonso J
authors: AJ
authors: Carrillo-Muñoz
authors: M Jesús
authors: MJ
authors: Payá
mesh_terms: D000818:Animals; D003881:Dermatomycoses / Q000201:enzymology / Q000382:microbiology / Q000662:veterinary*; D004283:Dog Diseases / Q000201:enzymology / Q000382:microbiology*; D004285:Dogs; D005656:Fungal Proteins / Q000032:analysis* / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008290:Malassezia / Q000201:enzymology* / Q000472:pathogenicity; D010032:Otitis Externa / Q000201:enzymology / Q000382:microbiology / Q000662:veterinary*; D010447:Peptide Hydrolases / Q000032:analysis* / Q000502:physiology; D010740:Phospholipases / Q000032:analysis* / Q000502:physiology; D014774:Virulence
chemical_list: D005656:Fungal Proteins; D010740:Phospholipases; D010447:Peptide Hydrolases
keywords: Actividad fosfolipasa; Actividad proteinasa; Dog; Malassezia pachydermatis; Otitis; Perro; Phospholipase activity; Proteinase activity