Question

Tuberculosis is caused by which of the following organisms?

• A. Treponema pallidum
• B. Mycobacterium tuberculosis
• C. Legionella pneumophila
• D. Neisseria meningitidis

Hint:

Always remember: Tuberculosis = Mycobacterium tuberculosis (acid-fast bacillus).

Answer 1

The Correct Option is B

Step 1: Understanding the disease.
Tuberculosis (TB) is a chronic infectious disease that primarily affects the lungs, though it can spread to other organs.
The causative organism is a slow-growing, acid-fast bacillus known as Mycobacterium tuberculosis.
Step 2: Transmission and pathology.
It spreads mainly through droplets released when an infected person coughs, sneezes, or speaks.
Inside the host, the bacteria survive within macrophages and form granulomas.
The disease can manifest as pulmonary TB or extrapulmonary TB (in lymph nodes, bones, kidneys, etc.).
Step 3: Analysis of options.
- (A) Treponema pallidum: Causes syphilis, not TB.
- (B) Mycobacterium tuberculosis: Correct causative agent of tuberculosis.
- (C) Legionella pneumophila: Causes Legionnaires’ disease, a type of pneumonia.
- (D) Neisseria meningitidis: Causes meningitis, not tuberculosis.
Step 4: Conclusion.
The organism responsible for tuberculosis is Mycobacterium tuberculosis.