Final answer:
Selective toxicity is the term that refers to the ability of an antimicrobial drug to target and harm the microbe without damaging the host. It is fundamental to effective antimicrobial therapy and deeply intertwined with a drug's mode of action.
Step-by-step explanation:
The ability of an antimicrobial drug to harm the target microbe without harming the host is known as selective toxicity. This concept is critical in the development and clinical use of antimicrobial drugs, as substances with high selective toxicity are more desirable for treating infections. Antimicrobial drugs achieve this by exploiting differences in the cellular structures and metabolic pathways between the microbe and the host, thus allowing them to target the infecting organism specifically. The term 'mode of action' refers to how a drug affects microbes at the cellular level, and different antibacterial drugs have distinct modes of action to achieve selective toxicity.
It is important to note that certain concepts like minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) describe the quantities of an antimicrobial drug required to inhibit or kill microbes, but these do not directly reflect selective toxicity. Instead, they are useful for determining the correct dose of a drug that is effective against a particular microbe.