We report here the results of a comparative analysis of 31 publicly available genomes (http://www.tbdb.org, Figure 1 , Table 1 ). These include eight closely related members of the Mtb complex that can cause tuberculosis disease, (two M. bovis strains and six Mtb strains). To gain further insight into the Mycobacterium cluster, we also included a related Rhodococcus (also involved in bioremediation), a pathogenic Nocardia, four Corynebacteria (two pathogens and two that are commercially useful in amino acid production), two Streptomyces (antibiotic-producing soil bacteria), Acidothermus cellulolyticus (a thermophilic actinobacteria from the hot springs of Yellowstone), Propionibacterium acnes (causative agent of common acne), and Bifidobacterium longum (a digestive track commensal often found Mycobacterium tuberculosis F11 (ExPEC) Y Y Causes TB; isolated from TB patient in S. Africa [5] Mycobacterium bovis BCG str. Pasteur 1173P2 Y Y Causes bovine TB; attenuated vaccine strain [6] Mycobacterium bovis AF2122/97 Y Y Causes bovine TB [7] Mycobacterium tuberculosis Haarlem Y Y Causes TB; MDR strain [5] Mycobacterium tuberculosis C Y Y Causes TB; isolated in NY City [5] Mycobacterium tuberculosis CDC1551 Y Y Causes TB; highly contagious & virulent strain [8] Mycobacterium ulcerans AGY99 Y Causes Buruli ulcer [9] Mycobacterium marinum Y From fish; Skin lesions in human [10] Mycobacterium leprae TN Y Y Causes leprosy [11] Mycobacterium avium 104 Y Opportunistic pathogen; can causeTB-type pulmonary infection [12] Mycobacterium avium subsp. Paratuberculosis K-10 Y Y Causes paratuberculosis; obligate pathogen of cattle [13] Mycobacterium sp. MCS Soil bacteria; degrades PAH [14] Mycobacterium sp. KMS Soil bacteria; degrades PAH [14] Mycobacterium smegmatis MC2155 Y Widely used model for Mtb isolated from human smegma; causes soft tissue lesions [12] Mycobacterium vanbaalenii PYR-1 Soil bacteria; degrades PAH [14] Mycobacterium gilvum Soil bacteria; Degrades PAH + wide variety of organic compounds [14] Mycobacterium abscessus Y Skin & soft tissue infections [15] Rhodococcus jostii RHA1 Soil bacteria important for biofuels research and bioremediation; degrades PCB + wide variety of organic compounds [16] Nocardia farcinica IFM 10152 Y Causes nocardiosis [17] Corynebacterium glutamicum ATCC 13032