Question

Which one of the following organisms has axial filaments?

• A. ( {Mycobacterium tuberculosis} )
• B. ( {Pasteurella multocida} )
• C. ( {Treponema pallidum} )
• D. ( {Shigella dysenteriae} )

Hint:

In microbiology, understanding the structural adaptations of pathogens like axial filaments can provide insights into their mechanisms of infection and mobility.

Answer 1

The Correct Option is C

Axial filaments, also known as periplasmic flagella, are a type of bacterial motility structure located beneath the outer membrane of certain spirochetes, which allows them to move in a corkscrew motion. Analysis of Each Option: (A) {Mycobacterium tuberculosis:} Incorrect. {Mycobacterium tuberculosis} is a bacillus-shaped bacterium known for causing tuberculosis. It does not have axial filaments. (B) {Pasteurella multocida:} Incorrect. {Pasteurella multocida} is a coccobacillus that typically affects animals and causes various infections. It does not possess axial filaments. (C) {Treponema pallidum:} Correct. {Treponema pallidum}, the causative agent of syphilis, is a spirochete bacterium that uses axial filaments for motility, enabling it to move through viscous environments such as connective tissue. (D) {Shigella dysenteriae:} Incorrect. {Shigella dysenteriae} is a rod-shaped bacterium that causes dysentery. It is non-motile and lacks axial filaments. Conclusion:
Explanation: Axial filaments are unique to certain spirochetes, aiding in their distinctive motility, which is critical for their pathogenicity and ability to invade host tissues. {Treponema pallidum} is a classic example of such an organism.