The Collaborative International Dictionary of English v.0.48:
mycobacterium \mycobacterium\ n.; pl. mycobacteria. Any of various rod-shaped bacteria, some saprophytic or causing diseases. [WordNet 1.5]WordNet (r) 3.0 (2006):
mycobacterium n 1: rod-shaped bacteria some saprophytic or causing diseases [syn: mycobacteria, mycobacterium]