Antimicrobial drugs are designed to target and eliminate harmful microorganisms causing infections without damaging the human host. This principle, known as selective toxicity, is fundamental in developing effective treatments that are toxic to pathogens but safe for humans. Achieving selective toxicity is challenging because the drug must distinguish between microbial cells and human cells.
The concept of selective toxicity was pioneered by Paul Ehrlich in the early 1900s. Ehrlich introduced the idea of the "magic bullet," a chemical agent that specifically targets disease-causing microbes. His work led to the first antimicrobial drug used to treat syphilis, marking a significant milestone in medical history. Although this drug is no longer in use, Ehrlich’s approach laid the groundwork for future antimicrobial development.
Later, Alexander Fleming discovered penicillin in 1928, the first true antibiotic widely used to combat bacterial infections. Fleming observed that the Penicillium mold produced a substance that inhibited bacterial growth on a Petri dish, leading to the development of penicillin as a powerful antibacterial agent. Penicillin revolutionized medicine in the 1940s and remains a cornerstone in treating bacterial infections.
Despite the success of antibiotics, the rise of antimicrobial resistance threatens their effectiveness. Resistance occurs when microbes evolve mechanisms to survive drug exposure, making infections harder to treat. This growing problem underscores the need for ongoing research and responsible use of antimicrobial drugs to preserve their efficacy.
In the context of antimicrobial therapy, the term chemotherapy refers broadly to the use of chemical agents to treat diseases caused by microbes, not just cancer. Antimicrobials encompass a wide range of drugs targeting different types of pathogens. These include antibacterials for bacteria, antivirals for viruses, antifungals for fungi, and antiparasitics for parasitic eukaryotes.
Within antibacterials, the term antibiotic specifically denotes substances produced naturally by organisms, such as penicillin from mold. In contrast, synthetic antibacterials are chemically manufactured in laboratories. Although the term antibiotic is commonly used to describe all antibacterial drugs, understanding this distinction is important for precise scientific communication.
