Definition of broad-spectrum activity: A broad-spectrum antibacterial agent such as chloramphenicol is best described as one that…

Introduction / Context:
“Broad-spectrum” is a standard descriptor in antimicrobial therapy. Misunderstanding it can lead to misuse of antibiotics and increased resistance.

Given Data / Assumptions:

• Chloramphenicol is cited as an example broad-spectrum antibacterial.
• We must select the most accurate definition of “broad-spectrum.”

Concept / Approach:
In antibacterial pharmacology, “broad-spectrum” refers to activity against a wide range of bacterial species, typically including both Gram-positive and Gram-negative organisms. It does not imply efficacy against fungi, protozoa, or viruses, nor universal lethality to all bacteria.

Step-by-Step Solution:
Define scope: broad activity within bacteria, not all microbes. Align with chloramphenicol’s spectrum: Gram-positive and Gram-negative coverage. Select the option that matches this definition precisely.

Verification / Alternative check:
Susceptibility tables list chloramphenicol as active against many Gram-positives and Gram-negatives, though resistance and toxicity limit modern use.

Why Other Options Are Wrong:

• Kills all bacteria: no single agent eradicates all species or spores.
• Kills numerous types of microbes: conflates antibacterial with antifungal/antiprotozoal effects.
• Kills all microorganisms: overbroad and inaccurate.

Common Pitfalls:
Assuming “broad-spectrum” equals “universal”; spectrum still has limits and clinical constraints.

Final Answer:
kills both Gram-positive and Gram-negative bacteria