Mycobacterium shigaense sp. nov., a novel slowly growing scotochromogenic mycobacterium that produced nodules in an erythroderma patient with severe cellular immunodeficiency and a history of Hodgkin's disease.

A novel slow-growing scotochromogenic mycobacterium was isolated from skin biopsies from a patient with a history of Hodgkin's disease and severe cellular immunodeficiency as an opportunistic pathogen. Clinical characterization of these lesions revealed papules and nodules with pathological granuloma formation. Genotypic analysis using 16S rRNA misidentified this isolate as Mycobacterium simiae. However, multiple gene analysis using the internal transcribed spacer between the 16S and 23S rRNA genes, and the rpoB and hsp65 genes revealed the presence of a novel mycobacterium. The antimicrobial susceptibility of this isolate was completely different from that of M. simiae. On the basis of these findings, we propose naming this new species Mycobacterium shigaense sp. nov., and conclude that multiple gene analysis is required for the appropriate diagnosis and treatment of non-tuberculous mycobacterial infections.