Which characteristic is unique to Mycobacterium?

• A. It is a spore former
• B. It survives phagocytosis
• C. It is anaerobic
• D. It is easily killed by antibiotics

Answer: (B)

Mycobacterium are intracellular pathogens that can persist inside macrophages after being engulfed. This survival inside phagocytic cells is enabled by a thick, waxy cell wall rich in mycolic acids, which resists digestion and can interfere with phagosome-lysosome fusion. That combination allows these bacteria to persist and replicate within immune cells, a hallmark feature often tested in questions about their behavior.

They do not form spores, so spore formation isn’t a trait of these organisms. They are not anaerobic; they require oxygen to grow. And they aren’t easily killed by antibiotics—treatment typically needs prolonged, multi-drug regimens because the cell wall limits antibiotic penetration and the bacteria can be intracellular.