What is a semisynthetic antimicrobial?

A semisynthetic antimicrobial refers to a modified version of a natural antibiotic. These compounds are chemically altered derivatives of naturally occurring antibiotics to enhance their efficacy, spectrum of activity, or to reduce resistance. By making specific modifications, scientists can improve characteristics such as absorption, distribution, metabolism, and elimination, making them more effective in treating infections caused by certain pathogens.

Natural antibiotics are isolated from microorganisms, while completely synthetic drugs are designed and manufactured entirely through chemical processes without any natural components. Semisynthetics bridge the gap between these two categories by starting with a natural base but incorporating synthetic modifications. This results in antibiotics that may retain the beneficial properties of the natural compound while potentially overcoming limitations such as spectrum of activity or adverse side effects.

Drugs without any antibiotic properties would not fit the definition of an antimicrobial at all, as they would not have the ability to inhibit or kill bacteria. Thus, the distinction made in the correct choice emphasizes the importance of the modifications applied to natural antibiotics to create effective semisynthetic alternatives.