Fungal dermatitis associated to Rhodotorula glutinis in dog (Canis familiaris): case report

ABSTRACT The fungi Rhodotorula sp was considered nonpathogenic, but with the increase of immunosuppressed humans in the last two decades, the species R. mucilaginosa, R. glutinis and R. minuta became potentially pathogenic agents. There have been few veterinary clinical reports associated with Rhodotorula spp. and this work aims to describe the first case of fungal dermatitis caused by R. glutinis in immunosuppressed dog due to visceral leishmaniasis and osteosarcoma in the city of Cuiabá-Mato Grosso. An 11-year-old male mongrel dog was examined to the Veterinary Hospital with skin lesions and the diagnosis was dermatophytosis and the treatment was implemented with topical tea tree oil for one month, but the treatment failed. The animal returned to the Veterinary Hospital with bleeding in the injured area of the tail and biopsy was performed for microbiological and histopathology evaluation. In the microbiological and histopathological analysis, yeast was isolated and yeast-like structures in silver staining were observed, respectively. The isolated yeast was identified as R. glutinis by DNA sequencing. A new treatment was implemented without clinical improvement. The animal was diagnosed with leishmaniasis and osteosarcoma, which probably caused immunosuppression, and its clinical conditions evolved to death.

摘要
红酵母属（Rhodotorula sp.）真菌曾被视为无致病性类群，但近二十年来随着免疫功能低下人群数量不断增加，胶红酵母（R. mucilaginosa）、粘红酵母（R. glutinis）与微小红酵母（R. minuta）已逐渐成为潜在致病病原体。目前关于红酵母属相关兽医临床病例的报道较为少见，本研究旨在报道巴西马托格罗索州库亚巴市首例由粘红酵母（R. glutinis）引发的、继发于内脏利什曼病（visceral leishmaniasis）与骨肉瘤（osteosarcoma）的免疫抑制犬真菌性皮炎病例。
受试对象为一只11岁雄性杂种犬，其因皮肤损伤前往兽医院就诊，初始诊断为皮肤癣菌病，予以局部涂抹茶树油（tea tree oil）治疗1个月，但治疗失败。该犬随后因尾部损伤部位出血再次就诊，医护人员采集活检样本以开展微生物学与组织病理学检测。微生物学分析成功分离得到酵母菌，银染色组织病理学观察到类酵母结构。经DNA测序（DNA sequencing）鉴定，该分离菌株为粘红酵母（R. glutinis）。后续实施的新增治疗方案未取得临床改善。该犬随后被确诊为利什曼病与骨肉瘤，二者大概率为其免疫抑制的诱因，最终病情恶化死亡。