土曲霉致双外耳道曲霉病

Aspergillosis of both ear canals caused by Aspergillus terreus:a case report

目的报道1例发生在双外耳道的曲霉病。方法取双耳耵聍行真菌直接镜检,将耵聍接种到沙堡培养基培养,并对培养出的病原菌进行形态学鉴定和rDNA序列分析。结果耵聍真菌直接镜检阳性,耵聍在沙堡培养基25℃培养长出沙褐色菌落,28℃小培养后光镜及扫描电镜下见分生孢子头呈柱状,顶囊半球形,直径约10μm,小梗双层,两层小梗的长度无明显差别,平行紧密生长在顶囊的上2/3处。分生孢子呈球形,小而光滑。分生孢子梗壁光滑、透明。提取真菌总DNA用PCR方法扩增rDNA序列,测序后登录Gene Bank进行比对,该菌与土曲霉菌株ATCC1012 rDNA序列一致性达100%,鉴定为土曲霉。患者外用4%氟康唑注射液直接滴耳,2次/d,治疗1个月后痊愈。结论确诊1例双外耳道土曲霉病,局部应用氟康唑注射液治疗外耳道曲霉病有效。

Objective A case of aspergillosis of both ear canals of a 55-year-old man was reported. Methods The ear wax taken from both ear canals were examined directly under microscopy, and incubated on Sabouraud dextrose agar （SDA） at 25℃, to identify the morphology and to analysis rDNA domain. Results Under microscopy hyphae were detected from the ear wax. Sandbrown colonies developed after the cerumen taken from both ear canals were incubated on SDA at 25℃. Microscopy and scanning electron microscopy showed：①conidial heads loosely columnar, vesicles subspherical ,about 10μm diam. ②Conidiogenous cells biseriate, metulae as long as the phialides. ③Conidia smooth walled, spherical to broadly ellipsoidal.④Conidiophore stipes smooth walled, hyaline. Nuclear DNA was extracted and the rDNA domain was amplified by PCR. PCR products was sequenced and compared with Gene Bank, which indicated the rDNA domain of the isolated fungus was consistency with Aspergillus terreus ATCC1012. The patient was treated by direct dropping of 4% fluconazol parenteral solution on his both ear canals twice a day and his symptoms completely disappeared after 1 month of treatment. Conclusion A case of aspergillosis of both ear canals was diagnosed and successfully treated by topical application of fluconazol parenteral solution.