n :  a bacterium of the genus Mycobacterium that is classified either as a distinct species (M. microti) or as a variety (M. tuberculosis var. muris) of the tubercle bacillus, that was first isolated from a wild European vole of the genus Microtus (M. agrestis), and that has been used to immunize individuals against the tubercle bacillus and a related bacterium (Mycobacterium bovis syn. M. tuberculosis var. bovis) .
 
 
 
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