ISOLATION AND CHARACTERIZATION OF A UNIQUE GROUP OF SLOWLY GROWING MYCOBACTERIA - DESCRIPTION OF MYCOBACTERIUM-LENTIFLAVUM SP-NOV

A distinct group of slowly growing mycobacteria was identified on the basis of growth characteristics, biochemical and lipid profiles, and n ucleic acid analyses. The isolates showed growth at 22 to 37 degrees C , yellow pigmentation, and negative tests for Tween 80 hydrolysis, nic otinic acid, nitrate reductase, and urease; tests for arylsulfatase, p yrazinamidase, and heat-stable catalase were variable. Analysis of cel lular fatty acids by gas-liquid chromatography and mycolic acids by th in-layer chromatography and high-performance liquid chromatography ind icated a distinctive pattern which was unlike those of other species. Determination of the 16S rRNA gene sequence showed a unique sequence c losely related to Mycobacterium simiae and M. genavense. On the basis of DNA homology studies, we suggest that these organisms are represent atives of a novel species, for which the name M. lentiflavum sp, nov. is proposed.