Question

A narrow spectrum antibiotic is active against:

• A. gram positive or gram negative bacteria
• B. gram negative bacteria only
• C. single organism or one disease
• D. both gram positive and gram negative bacteria

Answer 1

Answer: (B)

gram negative bacteria only

Drugs are classified based on their effects on gram-positive and gram-negative bacteria.

So, the drugs which are active against gram-negative bacteria are classified as narrow spectrum antibiotics and the drugs active against both gram positive and gram negative bacteria are called broad spectrum antibiotics.