Which statement correctly contrasts broad-spectrum and narrow-spectrum antibiotics?

Which statement correctly contrasts broad-spectrum and narrow-spectrum antibiotics?

• A. Broad-spectrum antibiotics affect a wide range of bacteria.
• B. Narrow-spectrum antibiotics affect a wide range of bacteria.
• C. Broad-spectrum antibiotics affect a narrow range of bacteria.
• D. Narrow-spectrum antibiotics kill viruses.

Answer: (C)

The key idea is how many bacteria a drug can affect. Broad-spectrum antibiotics target a wide range of bacteria, often including both Gram-positive and Gram-negative types, and can work against many different species. Narrow-spectrum antibiotics, on the other hand, are effective against a smaller, specific group of bacteria, chosen when the infecting organism is known or when culture results guide therapy. So the correct contrast is that broad-spectrum affects a wide range of bacteria, while narrow-spectrum affects a narrow range. The idea that broad-spectrum affects a narrow range would be inaccurate, and antibiotics don’t kill viruses, so that statement would also be incorrect.

The key idea is how many bacteria a drug can affect. Broad-spectrum antibiotics target a wide range of bacteria, often including both Gram-positive and Gram-negative types, and can work against many different species. Narrow-spectrum antibiotics, on the other hand, are effective against a smaller, specific group of bacteria, chosen when the infecting organism is known or when culture results guide therapy. So the correct contrast is that broad-spectrum affects a wide range of bacteria, while narrow-spectrum affects a narrow range. The idea that broad-spectrum affects a narrow range would be inaccurate, and antibiotics don’t kill viruses, so that statement would also be incorrect.