What is a notable characteristic of Mycobacterium tuberculosis?

Mycobacterium tuberculosis is known for having a distinctive characteristic that significantly contributes to its pathogenicity: it possesses a waxy cell wall composed primarily of mycolic acids. This unique structure is crucial for the bacterium’s survival as it makes the organism highly resistant to many antibiotics and other common antiseptics. The waxy nature of the cell wall also aids in evading the host’s immune system, enabling the bacteria to persist within macrophages, which are a type of immune cell that typically engulfs and destroys pathogens.

In contrast to the other options, Mycobacterium tuberculosis does not have a flagellum, as it is non-motile, and it does not reproduce exclusively in anaerobic conditions; it is capable of growth in aerobic conditions, which is significant for its survival in human hosts. Furthermore, the notion that it can only survive in the presence of other bacteria is inaccurate, as it is an independent pathogen that can thrive in its own environment. The key feature of its waxy cell wall is what primarily distinguishes it from other bacteria.