Mycobacterial Diseases
Open Access

Mycobacterium smegmatis: Exploring its Similarities with Mycobacterium tuberculosis

Nishmi Gunasingam^{* *}Correspondence: Nishmi Gunasingam, Department of Gastroenterology, St Vincent’s Hospital, Sydney, Australia, Email:

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Description

Mycobacterium tuberculosis, the causative agent of Tuberculosis (TB), is a well-known and highly infectious pathogen that affects millions of people worldwide. However, it is not the only member of the mycobacterium family with the potential to cause disease. Mycobacterium smegmatis, often considered a benign bacterium, shares significant genetic similarities with Mycobacterium tuberculosis and has emerged as an invaluable tool for studying the pathogenesis, treatment, and prevention of TB. In this article, we delve into the world of Mycobacterium smegmatis, exploring its characteristics, its similarities to Mycobacterium tuberculosis, and its role as a model organism for tuberculosis research.

Characteristics of Mycobacterium smegmatis

Mycobacterium smegmatis is a non-pathogenic, saprophytic bacterium commonly found in soil, water, and various environmental niches. One notable characteristic of Mycobacterium smegmatis is its high resistance to antibiotics, disinfectants, and other stressors. This resilience makes it an ideal model organism for studying drug resistance and evaluating potential therapeutic interventions. Additionally, Mycobacterium smegmatis has a small genome size, allowing researchers to study its genetic makeup more comprehensively.

Similarities to Mycobacterium tuberculosis

Despite being considered non-pathogenic, Mycobacterium smegmatis shares a striking genomic resemblance to Mycobacterium tuberculosis. The two bacteria share approximately 75% of their genetic material, and many of the virulence factors and mechanisms employed by Mycobacterium tuberculosis are conserved in Mycobacterium smegmatis. This genetic similarity enables researchers to investigate the fundamental aspects of TB infection using a safer and more accessible model organism. Furthermore, Mycobacterium smegmatis exhibits similar cell wall composition to Mycobacterium tuberculosis, which is a critical aspect in the pathogenesis of TB. Both bacteria have a unique, hydrophobic outer membrane rich in mycolic acids, which protects them from host immune defenses and contributes to their ability to persist in the body. Studying the cell wall composition of Mycobacterium smegmatis aids in understanding the mechanisms employed by Mycobacterium tuberculosis to evade the immune system.

Role as a model organism for tuberculosis research

Mycobacterium smegmatis has become a valuable tool for researchers studying tuberculosis due to its genetic similarity and practical advantages over Mycobacterium tuberculosis. The nonpathogenic nature of Mycobacterium smegmatis eliminates the risks associated with working directly with highly infectious Mycobacterium tuberculosis strains, allowing for safer experimentation and more accessible research. Researchers have exploited this similarity to examine various aspects of TB, including drug resistance, host-pathogen interactions, immune response, and potential vaccine candidates. Mycobacterium smegmatis has proven especially useful in investigating the mechanisms of drug resistance in TB. By introducing known drug resistance genes into Mycobacterium smegmatis, researchers can study how these genes affect drug efficacy and develop strategies to combat drug resistance. Moreover, Mycobacterium smegmatis has been employed to explore the host immune response to TB. By infecting macrophages or other immune cells with Mycobacterium smegmatis, researchers can simulate the initial stages of TB infection and examine the immune response, ultimately leading to a better understanding of the complex.