The main difference between mycobacterium tuberculosis and nontuberculous mycobacteria is that M. tuberculosis is a pathogenic bacterium that causes tuberculosis, whereas nontuberculous mycobacteria are environmental mycobacteria that do not cause tuberculosis or leprosy.
M. tuberculosis and nontuberculous mycobacteria are two types of mycobacteria that belong to the phylum Actinomycetota. Moreover, they are non-motile, long, rod-shaped, aerobic bacteria.
Key Areas Covered
1. What is Mycobacterium Tuberculosis
– Definition, Characteristics, Features
2. What is Nontuberculous Tuberculosis
– Definition, Characteristics, Features
3. Similarities Between Mycobacterium Tuberculosis and Nontuberculous Mycobacteria
– Outline of Common Features
4. Difference Between Mycobacterium Tuberculosis and Nontuberculous Mycobacteria
– Comparison of Key Differences
Key Terms
Mycobacterium Tuberculosis, Nontuberculous Mycobacteria
What is Mycobacterium Tuberculosis
Mycobacterium tuberculosis is a species of pathogenic bacteria that causes the disease tuberculosis. It belongs to the family Mycobacteriaceae. Robert Koch discovered the bacteria in 1882. These bacteria consist of mycolic acid. Therefore, they contain a waxy coating on the cell surface, which is unusual. Therefore, the bacteria can weakly appear Gram-positive. Moreover, acid-fast staining and fluorescence staining are important in the staining of M. tuberculosis. Apart from that, the most frequent diagnostic methods of M. tuberculosis include the tuberculin skin test, culture, acid-fast stain, and PCR.
Figure 1: M. tuberculosis
Furthermore, M. tuberculosis is highly aerobic, and therefore, it requires high levels of oxygen. In addition, it is a pathogenic bacterium that infects the mammalian respiratory system. Moreover, this bacterium can infect other organs of the body, including the kidney, brain, and spin. In the meanwhile, there are two conditions of tuberculosis disease. They are latent TB infection and TB disease. In the latent TB infection, M. tuberculosis can live in the body without showing symptoms. However, when the immune system cannot fight against the growth of M. tuberculosis, the bacterium can cause the disease. More importantly, the major symptoms of tuberculosis disease include a bad cough, pain in the chest, and weakness.
What are Nontuberculous Mycobacteria
Nontuberculous mycobacteria are environmental mycobacteria or atypical mycobacteria. They do not cause tuberculosis or leprosy. In addition, they do not form pulmonary diseases that are similar to tuberculosis. On the other hand, diseases, excluding tuberculosis, are mycobacteriosis. These diseases occur in many animals, including humans. Moreover, nontuberculous mycobacteria occur in soil and water. Apart from that, they can form pulmonary infections that resemble tuberculosis.
Figure 2: M. tuberculosis in the Lungs
Moreover, the common nontuberculous mycobacteria include M. avium complex (MAC), M. kansasii, and M. abscessus. They live in marshland, wet soil, rivers, streams, and estuaries. In addition, different strains prefer different environmental conditions. Exposure to the environment can cause infections in humans by these bacteria. However, the transmission of the disease from animal to human and human to a human does not occur in nontuberculous mycobacteria.
Similarities Between Mycobacterium Tuberculosis and Nontuberculous Mycobacteria
- M. tuberculosis and nontuberculous mycobacteria are two types of mycobacteria.
- They belong to the phylum Actinomycetota. Also, they are non-motile, long, rod-shaped, aerobic bacteria.
- Their cell walls have Gram-positive and Gram-negative features. In addition, the cell walls of the mycobacteria are thick, hydrophobic, and mycolic acid-rich cell walls made up of arabinogalactan and peptidoglycan.
- They contain a capsule, and most of the mycobacteria do not form endospores.
Difference Between Mycobacterium Tuberculosis and Nontuberculous Mycobacteria
Definition
M. tuberculosis refers to a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis, while nontuberculous mycobacteria refer to the mycobacteria other than M. tuberculosis (the cause of tuberculosis) and M. leprae (the cause of leprosy).
Importance
M. tuberculosis is a pathogenic bacterium that causes tuberculosis, while nontuberculous mycobacteria are environmental bacteria that are not pathogenic.
Examples
Tuberculous mycobacteria include M. tuberculosis and M. leprae while nontuberculous mycobacteria include M. marinum, M. bovis, etc.
Conclusion
In brief, M. tuberculosis and nontuberculous mycobacteria are two types of mycobacteria that belong to the phylum Actinomycetota. Generally, they are non-motile, long, rod-shaped, aerobic bacteria. M. tuberculosis is a type of pathogenic bacteria that causes tuberculosis. Moreover, the two types of tuberculous bacteria include M. tuberculosis and M. leprae. In comparison, nontuberculous mycobacteria are environmental bacteria that are not pathogenic. Some examples of nontuberculous mycobatceria are M. marinum, M. bovis, etc. Therefore, the main difference between mycobacterium tuberculosis and nontuberculous mycobacteria is their pathogenic nature.
References:
- “Latent TB Infection and TB Disease.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 11 Dec. 2020,
- “Nontuberculous Mycobacteria (NTM) Infections.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 12 Aug. 2019,
Image Courtesy:
- “TB Culture” By Dodo – Own work (Public Domain) via Commons Wikimedia
- “Cavitary tuberculosis” By Yale Rosen – Own Work (CC BY-SA 2.0) via Commons Wikimedia
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