Mycobacterium brumae sp. nov., a rapidly growing, nonphotochromogenic mycobacterium

Abstract

Strains of a new species of rapidly growing, nonphotochromogenic mycobacteria, Mycobacterium brumae, have been isolated from water, soil, and human sputum samples in Barcelona, Spain. The inclusion of this organism in the genus Mycobacterium is based on its acid-alcohol fastness, its DNA G+C content, its mycolate pattern, and its mycolate pyrolysis esters. A study of 11 strains showed that they form a homogeneous group with an internal phenotypic similarity value of 94.9 ± 3.79%. The results of a comparison with 39 other mycobacterial species and subspecies are also presented. DNA relatedness studies showed that the M. brumae strains studied form a single DNA hybridization group which is less than 30% related to 15 other species of the genus Mycobacterium. Thin-layer chromatographic analysis showed that only α-mycolates are present. Unlike Mycobacterium fallax and Mycobacterium triviale α-mycolates, M. brumae α-mycolates release only 22-carbon atom esters after pyrolysis. Strain CR-270 is the type strain; a culture of this strain has been deposited in the Collection Nationale de Cultures de Microorganismes de l'Institut Pasteur, Paris, France, as strain CIP 103465.