Question

Arrange the following disease causing agents in order of their discovery
(A). Yersinia pestis (Plague)
(B). Salmonella typhi (Typhoid fever)
(C). Treponema pallidium (Syphilis)
(D). Clostridium tetani (Tetanus)
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D).
• B. (A), (C), (B), (D).
• C. (B), (D), (A), (C).
• D. (C), (B), (D), (A).

Hint:

The late 1800s was a period of intense discovery for bacteriology, thanks to the work of pioneers like Koch and Pasteur. Most major bacterial pathogens for diseases known since antiquity were identified during this time.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question requires arranging the given pathogenic bacteria in the chronological order of their discovery. This tests knowledge of the history of microbiology, particularly during the "Golden Age" in the late 19th and early 20th centuries.

Step 2: Detailed Explanation:
Let's look at the discovery date for each bacterium:
\[\begin{array}{rl} \bullet & \text{(B) Salmonella typhi: The causative agent of typhoid fever was first observed by Karl Joseph Eberth in 1880. } \\ \bullet & \text{(D) Clostridium tetani: The causative agent of tetanus was isolated from soil by Arthur Nicolaier in 1884. } \\ \bullet & \text{(A) Yersinia pestis: The causative agent of plague was discovered by Alexandre Yersin in 1894 during the plague pandemic in Hong Kong. } \\ \bullet & \text{(C) Treponema pallidum: The causative agent of syphilis, a spirochete bacterium, was identified by Fritz Schaudinn and Erich Hoffmann in 1905. } \\ \end{array}\] Arranging these in chronological order gives the sequence: Salmonella typhi (1880), Clostridium tetani (1884), Yersinia pestis (1894), and Treponema pallidum (1905).

Step 3: Final Answer:
The correct order of discovery is (B), (D), (A), (C).