Use of contact plates for the quantitative culture of Malassezia pachydermatis from canine skin

The Malassezia pachydermatis populations of the axilla and groin of 12 normal and 12 atopic dogs were compared using tape-strips and contact plates. When assessed by either method, the mean density of yeasts in the groin of the atopic dogs was significantly greater (P<0.05) than that of the normal dogs, suggesting that the cutaneous microenvironment of the groin region of the atopic dogs favoured colonisation by this yeast. Differences between the counts from the axilla were not significant. The frequency of isolation of yeasts from both dogs and sites was significantly higher (P<0.05 and P<0.001, respectively) in the atopic group. There was a very highly significant correlation (P<0.001) between the tape-strip counts and contact plate counts in the atopic group only. This study suggests that isolation of numerous M pachydermatis colonies from the axilla and groin of dogs using contact plates is indicative of elevated skin surface populations. The simplicity of the contact plate method makes it suitable for the routine quantitative culture of cutaneous M pachydermatis populations in dogs with dermatological disease.