Mycobacterium holsaticum sp. nov

Abstract

Strains of a novel species of the rapidly growing mycobacteria, Mycobacterium holsaticum sp. nov., were isolated from various clinical specimens. The isolates grew at 22-40 degrees C, were positive for nitrate and tellurite reduction, had phosphatase, urease, nicotinamidase and pyrazinamidase activities, were resistant to isoniazid and rifampin and were susceptible to streptomycin and ethambutol. Analyses of the 165 rRNA gene and a fragment of the heat-shock protein gene hsp65 revealed unique nucleotide sequences. A phylogenetic analysis based on the comparison of the 16S rDNA sequence with that of other mycobacterial species allocated the strain to the rapidly growing mycobacteria. A conspicuous characteristic of the novel species is the similarity of the species-specific sequence of the 16S rRNA gene to the sequence of the Mycobacterium tuberculosis complex, resulting in a cross-reaction with the AccuProbe for the M. tuberculosis complex when performed with a 5 min selection step. The type strain of the novel species is strain 1406(T) ( = DSM 44478(T) = CCUG 46266(T)). Another strain of M. holsaticum sp. nov., strain 5050, which differed in the internal transcribed spacer sequence, was deposited as DSM 44479 ( = CCUG 46267).