Question

An indicator of faecal pollution is

• A. Salmonella
• B. Escherichia coli
• C. Streptococcus
• D. Staphylococcus

Hint:

An ideal fecal indicator bacterium should:
- Be consistently present in feces.
- Be easily detectable by simple laboratory methods (e.g., IMViC test).
- Have survival patterns similar to pathogens.
E. coli meets these criteria perfectly.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
To evaluate the sanitary quality of water and seafood, microbiologists test for specific indicator bacteria that signify fecal contamination.

Step 2: Detailed Explanation:
Escherichia coli (E. coli) is a coliform bacterium that resides naturally in the gastrointestinal tract of warm-blooded animals.
Because it is consistently present in high numbers in feces and does not typically multiply or persist indefinitely in clean natural waters, its detection in water or fish samples is the universally accepted, standard indicator of fresh fecal pollution.

Step 3: Final Answer:
The classic indicator of fecal pollution is Escherichia coli, which corresponds to option (B).