关键词: 着色真菌病, 球孢枝孢, 微生物敏感性试验, 序列分析，DNA

Abstract:

A 53-year-old male patient was admitted to the hospital on March 26, 2006. Ten years prior to the presentation, a small furuncle developed on the dorsum of his right hand, and subsided after 2-week treatment with erythromycin ointment; one month later, a broadbean-sized cutaneous ulcer developed on the dorsum of the same hand. After anti-infective treatment, the ulcer healed while the lesional skin thickened, and long-term topical treatment with compound dexamethasone acetate cream showed no obvious effect. Dermatological examination revealed an irregular verrucous plaque measuring 2.5 cm × 4 cm with little exudation on the dorsum of the right hand. KOH preparation of the skin lesion revealed brown spores. Sabouraud′s dextrose agar culture grew restricted, velvety and dark green colony, and microscopy revealed branched, globular conidiophores generated by cladospores. DNA sequencing showed that the isolate was different from Cladosporium sphaerospermum（AB100654） by 2 bases in the sequence of D1/D2 region of 26S rDNA, from Cladosporium sphaerospermum（AY625063） by 5 bases in the sequence of internal transcribed spacer 1 and 2 （ITS 1 and ITS 2）, but fully consistent with Cladosporium sphaerospermum （AM176719） in the sequence of ITS region. The isolate was identified as Cladosporium sphaerospermum. Hematoxylin-eosin stain of the lesional tissue revealed granulomatous changes, and PAS stain demonstrated brown spores. A diagnosis of phaeohyphomycosis was made. Antifungal susceptibility testing indicated that the isolate was highly sensitive to itraconazole. The lesion obviously subsided after treatment with oral itraconazole 0.2 g once daily for 8 weeks, but the patient was lost to follow up 2 months later.

Key words: Cladosporium sphaerospermum