Abstract: Objective To report an unusual case of disseminated cutaneous infection with Mycobacterium abscesses.Methods A complete clinical examination was performed for this patient.Flow cytomerry was used to measure the cellular immunity level of the patient.Tissue samples were obtained from the skin lesions,and subjected to acid-fast staining,histopathological examination and mycobacterium culture.PCR-restriction' fragment length polymorphism(RFLP) analysis of hsp65 gene with endonucleases BstE Ⅱ and Hae Ⅲ,and gene sequencing of hsp65 and 16sRNA genes,were applied to identify the isolate from skin lesions of the patient.Results The patient was a 22 years old female with disseminated cutaneous infection.The lesions began as symmetrical inflammatory erythema on the face and neck 1 year ago without obvi ous inducements,and gradually developed into small papules,nodules and erythematous infiltrated plaque,which then spread to the trunk and extremities.Flow cytometry revealed that her CD4⁺ lymphocyte count was lower than normal.The patient was negative for HIV antibody.Mycobacterium colonies was seen to grow on Lowenstein-Jensen(L-J) medium after two times of multiple-tubes culture at 37℃and 32℃ for 3-5 days.PCR-RFLP showed that the restriction endonuclease pattern of the clinical isolate was consistent with that of M.abscesses.Gene sequencing revealed a homology of 99.75% and 100% in hsp65 and 16SrRNA gene respectively between the isolate and M.abscesses.After two months of treatment with rifampin,isoniazid,levofloxacin,clarithromycin and thymosin,the lesions markedly resolved and CD4⁺ T cell count rose to normal level.Six months later,nearly all the lesions on the neck,trunk and extremities resolved with pigmented macules and atrophic scar left.Conclusions The clinical isolate is confirmed to be M.abscesses by phenotype,restriction endonuclease pattern and gene sequencing.Therapeutic efficiency could be achieved with antibiotics in combination with immunomodulator.

Key words: Mycobacterium, Mycobacterium infections