Mycobacterium massiliense Type II genotype leads to higher level of colony forming units and TNF-α secretion from human monocytes than Type I genotype.

Recently, we introduced a novel Mycobacterium massiliense Type II genotype from Korean patients, in which all isolates showed only a rough (R) colony morphotype. In this study, we sought to compare clinical factors and virulence potentials of two genotypes of M. massiliense, Type I and Type II.

Discovery of a novel hsp65 genotype within Mycobacterium massiliense associated with the rough colony morphology.

So far, genetic diversity among strains within Mycobacterium massiliense has rarely been studied. To investigate the genetic diversity among M. massiliense, we conducted phylogenetic analysis based on hsp65 (603-bp) and rpoB (711-bp) sequences from 65 M.