Mycobacterium malmoense sp. nov.

Strains of a new type of group III nonphotochromogenic mycobacteria have been repeatedly isolated from four patients with clinical and roentgenological signs of lung mycobacteriosis. These strains split nicotinamide and pyrazinamide as do those of Mycobacterium avium, but they show no esterase activity. Furthermore, the strains produce thermolabile catalase and hydrolyze Tween 80. They also have a unique lipid pattern and special sensitins and agglutinins. These strains, therefore, are considered as belonging to a new species of pathogenic, nonphotochromogenic mycobacteria, for which we propose the name Mycobacterium malmoense. Strain M-O 816 is the type strain, and it has been deposited in the American Type Culture Collection under the number 29571.