Native-valve endocarditis caused by Mycobacterium chelonae, misidentified as polymicrobial gram-positive bacillus infection.

Mycobacterium chelonae, a species of rapidly growing mycobacteria, may grow in routine blood culture media and stain as gram-positive bacilli, which may cause diagnostic confusion. A patient with native-valve endocarditis caused by M. chelonae, which was misidentified as various gram-positive bacilli, is presented.