Mycobacterium stomatepiae sp. nov., a slowly growing, non-chromogenic species isolated from fish

1 Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK 2 School of Veterinary Medicine, Ilam University, PO Box 69315-516, Ilam, Iran 3 Skretting, Frazione San Zeno, 37060 Mozzecane, Italy Correspondence Fazel Pourahmad fp4{at}stir.ac.uk Slowly growing, non-chromogenic mycobacteria were isolated from striped barombi mbo cichlids ( Stomatepia mariae ) maintained at the London Zoo Aquarium, UK. The isolates could be differentiated from other slowly growing, non-pigmented mycobacteria by a combination of phenotypic features including their inability to grow at 37 °C, positive tests for heat-stable catalase, tellurite reduction and arylsulfatase activity, and the absence of urease activity, Tween 80 hydrolysis, nitrate reductase, iron uptake and semiquantitative catalase. The almost full-length 16S rRNA gene sequence, together with partial sequences from the 65 kDa heat-shock protein ( hsp65 ) and the β -subunit of the bacterial RNA polymerase ( rpoB ) genes and the 16S–23S internal transcribed spacer 1 (ITS 1) region were identical for all three novel strains, but distinct from those of all known mycobacterial species. Phylogenetic analysis based on 16S rRNA gene sequences placed the novel isolates within the slowly growing mycobacteria group in close proximity to Mycobacterium florentinum . Based on genotypic and phenotypic findings, it is proposed that these isolates represent a novel species of the genus Mycobacterium , for which the name Mycobacterium stomatepiae sp. nov. is proposed with strain T11 T (=DSM 45059 T =CIP 109275 T =NCIMB 14252 T ) as the type strain. Abbreviations: ITS, internal transcribed spacer; MSR, M. simiae -related; PRA, PCR-restriction enzyme analysis The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA, hsp65 and rpoB gene sequences and ITS 1 region of M. stomatepiae sp. nov. T11 T are AM884331 , AM902968 , AM885873 and AM902938 , respectively. Neighbour-joining phylogenetic trees based on hsp65 (Fig. S1) and rpoB (Fig. S2) gene sequences of M. stomatepiae sp. nov. and selected mycobacterial species, and the oligonucleotides used for 16S rRNA gene sequencing (Table S1) are available with the online version of this paper.