A case of skin infection caused by Mycobacterium szulgai / 中华皮肤科杂志

ABSTRACT

A 7?year?old girl presented with a plaque on the left side of the face for 4 years. Skin examination revealed a well?marginated circular firm plaque measuring 6 cm × 5 cm in size on the left side of the face with purulent crusts on the surface, which was nontender to palpation. Histopathologic study showed ulceration and necrosis in some areas in the epidermis, diffuse dermal infiltration of lymphocytes, histiocytes and epithelioid cells with the presence of many neutrophilic granulocytes in some regions. Both periodic acid?Schiff(PAS)staining and acid?fast staining were negative. After 25 days of tissue culture, scotochromogenic Mycobacterium colonies grew, and colony smears showed positive acid?fast staining. The sequences of 16S rRNA and hsp65 genes of the fungal isolate showed 100%and 99%homology with those of Mycobacterium szulgai, respectively. After the treatment with rifampicin, isoniazid and ethambutol, the patient′s condition was improved.