Mycobacterium florentinum sp. nov., isolated from humans.

Eight mycobacterial strains isolated during an 11 year period from the sputum of independent patients with various pulmonary disorders and, in one case, from a lymph node of a young girl, were found to present identical features. Phenotypic and genotypic characteristics revealed that the most closely related species to these test isolates were Mycobacterium triplex and Mycobacterium lentiflavum. However, the lipids of the cell wall of the test isolates differed from those of the latter species by TLC and presented unique profiles by both GC and HPLC. Genotypic analysis showed that they had unique 16S rRNA gene and internal transcribed spacer (ITS) sequences, and could be differentiated from all other mycobacterial strains by PCR restriction analysis of hsp65. The strains presented high resistance to antimycobacterial drugs. The name Mycobacterium florentinum sp. nov. is proposed for this taxon, with strain FI-93171(T) (=DSM 44852(T) = CIP 108409(T)) as the type strain.