First isolation of Exophiala dermatitidis from a dog: identification by molecular analysis

The present study deals with the first isolation of Exophiala dermatitidis from a dog. The dog had a history of multicentric lymphoma for 4 months. On physical examination, 10-15 black or purple subcutaneous nodules were detected on the dorsum of the right neck. Microscopic examination of biopsy specimen from the nodules disclosed lymphocytes, neutrophils and moniliform hyphae. The colony of the clinical isolate was flat with black aerial hyphae and a wet margin after 2 weeks incubation on Sabouraud's dextrose agar at 27 degrees C. The microscopic examination of the clinical isolate revealed that hyphae were brown, septate, and smooth, producing branched or unbranched conidiospores laterally or on the apex. The conidia were one celled, subglobose, elliptical to cylindrical, smooth and hyaline. Nucleotide sequence analysis of the chitin synthase 2 (CHS2) gene fragments from the isolate and a reference strain of E. dermatitidis showed more than 99% similarity.