Which term describes an antimicrobial that inhibits bacterial growth but does not kill?

• A. Bacteriostatic
• B. Bactericidal
• C. Kirby-Bauer Test
• D. Minimum Inhibitory Concentration (MIC)

Answer: (A)

Distinguishing bacteriostatic from bactericidal effects is what this item is about. An antimicrobial that inhibits growth but does not kill reduces bacterial replication, leaving viability intact and allowing the immune system to clear the infection. This action is called bacteriostatic, and it relies on the host’s defenses to finish the job. If the agent were bactericidal, it would actively kill bacteria, lowering their numbers directly. The Kirby-Bauer test is a disk-diffusion method used to assess susceptibility by measuring zones of inhibition, not to identify whether the agent halts growth or kills. The minimum inhibitory concentration is the lowest concentration that prevents visible growth in vitro, but it does not specify whether the bacteria are merely inhibited or killed.