Mycobacterium heckeshornense sp nov., a new pathogenic slowly growing Mycobacterium sp causing cavitary lung disease in an immunocompetent patient

A pathogenic scotochromogenic Mycobacterium xenopi-like organism was isolat ed from the lung of an immunocompetent young woman. This pathogen caused se vere bilateral cavitary lung disease, making two surgical interventions nec essary after years of chronic disease. This case prompted us to characteriz e this mycobacterium by a polyphasic taxonomic approach. The isolate contai ned chemotaxonomic markers which were typical for the genus Mycobacterium, i.e., the meso isomer of 2,6-diaminopimelic acid, arabinose, and galactose as diagnostic whole-cell sugars, MK-9(H-2) as the principal isoprenoid quin one, a mycolic acid pattern of alpha -mycolates, ketomycolates, and wax est er mycolates, unbranched saturated and unsaturated fatty acids plus a signi ficant amount of tuberculostearic acid, and small amounts of a C-20:0 secon dary alcohol. On the basis of its unique 16S rRNA and 16S-23S spacer gene s equences, we propose that the isolate should be assigned to a new species, Mycobacterium heckeshornense. This novel species is phylogenetically closel y related to M. xenopi. The type strain of M. heckeshornense is strain S369 (DSM 44428(T)). The GenBank accession number of the 16S rRNA gene of M. he ckeshornense is AF174290.