title: Clinical, microscopic and microbial characterization of exfoliative superficial pyoderma-associated epidermal collarettes in dogs.
abstract: BACKGROUND
  The microscopic and microbial features of the spreading epidermal collarettes of canine exfoliative superficial pyodermas are poorly characterized.
  
  
  OBJECTIVE
  To characterize the clinical, cytological, microbial and histopathological features of epidermal collarettes in five dogs.
  
  
  RESULTS
  Cytology from the margins of collarettes identified neutrophils, extracellular and intracellular cocci within neutrophils but no acantholytic keratinocytes. Phenotypic and genotypic analyses identified all bacterial isolates from the centre and margin of five epidermal collarettes as Staphylococcus pseudintermedius. PCRs of collarette-associated Staphylococcus strains did not amplify genes encoding for the known exfoliative toxins expA and expB, whereas the predicted siet and speta amplification products were detected in all isolates. Microscopically, epidermal collarettes consisted of interfollicular, epidermal spongiotic pustules. Advancing edges of lesions consisted of peripheral intracorneal clefts in the deep stratum disjunctum above an intact stratum compactum; they contained lytic neutrophil debris, bacterial cocci and fluid, but no acantholytic keratinocytes. This intracorneal location of bacteria was confirmed using Gram stains and fluorescent in situ hybridization with eubacterial- and Staphylococcus-specific probes. The indirect immunofluorescence staining patterns of desmoglein-1, desmocollin-1, claudin-1, E-cadherin and corneodesmosin were discontinuous and patchy in areas of spongiotic pustules, whereas only that of corneodesmosin was weaker and patchy in advancing collarette edges.
  
  
  CONCLUSIONS
  Epidermal collarettes represent unique clinical and histological lesions of exfoliative superficial pyodermas that are distinct from those of impetigo and superficial bacterial folliculitis. The characterization of possible causative staphylococcal exfoliatin proteases and the role of corneodesmosin in collarette pathogenesis deserve further investigation.
authors.affiliation: Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, 2200 College Station Road, Georgia, GA, 30605, USA.|Comparative Medicine Institute, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.|Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
authors.forename: Frane
authors.initials: F
authors.lastname: Banovic
authors.affiliation: Department of Population Health and Pathobiology, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Linder
authors.affiliation: Comparative Medicine Institute, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.|Department of Clinical Sciences, College of Veterinary Medicine, NC State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
authors.forename: Thierry
authors.initials: T
authors.lastname: Olivry
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology*; D004285:Dogs; D005098:Exotoxins / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence / Q000662:veterinary; D008297:Male; D011711:Pyoderma / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D012867:Skin / Q000382:microbiology / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013210:Staphylococcus / Q000235:genetics
chemical_list: D005098:Exotoxins