Question

Statement I: Typhoid bacteria are transmitted through contaminated food and water.
Statement II: Salmonella typhi is a gram-positive bacterium.

• A. Statement I and II are correct
• B. Statement I and II are incorrect
• C. Statement I is correct II is incorrect
• D. Statement I is incorrect II is correct

Hint:

Salmonella is a Gram-negative enterobacterium.
The Widal test is the standard serological test used to diagnose typhoid fever by detecting antibodies against O and H antigens of the bacteria.

Answer 1

The Correct Option is C

Step 1: Check the transmission route first.
Typhoid spreads through the fecal oral route, meaning contaminated food and water carrying the bacteria from an infected person, which matches statement I exactly.
Step 2: Check the Gram staining property.
Salmonella typhi has a thin peptidoglycan layer with an outer membrane, the defining structure of a Gram negative cell wall, so it stains pink, not purple, under the Gram stain.
Step 3: Combine the two checks.
Statement I about transmission is accurate while statement II wrongly calls the bacterium Gram positive.
Final answer: Option 3, statement I correct, statement II incorrect.