Question

A narrow-spectrum antibiotic is active against ___.

• A. Gram-negative bacteria only.
• B. Both gram-positive and gram-negative bacteria.
• C. Gram-positive or gram-negative bacteria.
• D. Single organism or one disease.

Answer 1

The correct option is C Gram-positive or gram-negative bacteria.

Narrow-spectrum antibiotics:

Narrow-spectrum antibiotics act upon a few types of bacteria. They are active against gram-positive or gram-negative bacteria.
Narrow-spectrum bacteria are used for specific infections when the microorganism is known and will not kill normal organisms in the body.

Both types of antibiotics work well to treat infections. Some examples of narrow-spectrum antibiotics are penicillin, macrolides and vancomycin.
Broad-spectrum antibiotics, on the contrary, target many types of bacteria and are not specific in action.

So, option (A) is correct.