Mycobacterium terrae complex (MTC) was first characterized in 1981 by the International Working Group in Mycobacterial Taxonomy (IWGMT). The initial MTC consisted of two nonchromogenic slowly growing species: M. terrae and Mycobacterium nonchromogenicum (1, 2). Phenotypic separation within the group was often difficult, and molecular methods were not available, making establishment of species pathogenicity uncertain (3).The complex is recognized as an environmental contaminant of sputum and a cause of tenosynovitis and osteomyelitis primarily of the fingers and wrist (3-35). Whether one or more members of the complex are true respiratory pathogens has not been established (1, 22).The first published case report of tenosynovitis caused by the MTC was by Hirata and Tomiyama in 1976 (4). There have been approximately 34 additional case reports published since then, identified using nonmolecular methods (3-25), with 14 cases identified using molecular methods (26)(27)(28)(30)(31)(32)(33)(34)(35)(36) (Tables 1 and 2). With the exception of four isolates of M. arupense, including the original description of M. arupense (28), details of the methods and/or explicitly stating a 100% 16S rRNA gene sequence identity to recognized species for the remaining cases with molecular identifications have been absent (Table 2).An excellent history and species update of the M. terrae complex based on multigene sequencing targets was published by Tortoli et al. (1). He noted that the presence of a two nucleotide insertion in helix 18 of the 16S rRNA gene (bp ϳ430 to 500; hypervariable region B or region V3) provided a consistent signature sequence for members of the MTC compared to other slowly growing mycobacteria (37,38). He also characterized several new species in the complex, including Mycobacterium heraklionense and Mycobacterium engbaekii (1).The greater availability of DNA sequencing (59) Citation Vasireddy R, Vasireddy S, Brown-Elliott BA, Wengenack NL, Eke UA, Benwill JL, Turenne C, Wallace RJ, Jr. 2016. Mycobacterium arupense, Mycobacterium heraklionense, and a newly proposed species, "Mycobacterium virginiense" sp. nov., but not Mycobacterium nonchromogenicum, as species of the Mycobacterium terrae complex causing tenosynovitis and osteomyelitis.
