mycobacterium heckeshornense mycobacterium heckeshornense mycobacterium heckeshornense is a species of the phylum actinomycetota (gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus mycobacterium. mycobacterium heckeshornense scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: mycobacteriales family: mycobacteriaceae genus: mycobacterium species: m. heckeshornense binomial name mycobacterium heckeshornenseroth et al. 2001, dsm 44428 description gram-positive, nonmotile and acid-fast rods. cells are typically rod-shaped, with some coccoid forms. colony characteristics smooth, yellow scotochromogenic colonies appear after 4 weeks of culture. physiology slowly growing organism, colonies appear after 4 weeks of growth. able to grow at 37 °c and 45 °c. differential characteristics the phylogenetic position of this species is within the cluster defined by m. xenopi and m. botniense. key differentiating features are negative tests for arylsulfatase and pyrazinamidase and susceptibility to antimycobacterial drugs. pathogenesis seems to be pathogenic in immunocompetent humans. biosafety level unknown type strain the type strain was isolated from human lung by bronchoscopy. strain s369 = ccug 51897 = dsm 44428