Definition of antibiotics as antibacterial antimicrobials

Summary

An antibiotic is a type of antimicrobial substance that is active against bacteria. In medical usage, antibiotics are considered a major class of antibacterial agents used to treat and prevent bacterial infections, and they work either by killing bacteria (bactericidal) or by inhibiting their growth (bacteriostatic). Although the term “antibiotic” can be used broadly to oppose microbes, the usual definition in medicine focuses on antibacterial drugs, such as penicillin. Antibiotics are part of a wider category called antibacterials, which includes bactericides, bacteriostatics, antibacterial soaps, and chemical disinfectants. While some antibiotics may also have activity against certain protozoa, antibiotics are not effective against viruses or fungi. Historically, the term evolved from an earlier, narrower meaning—substances produced by microorganisms that antagonize other microbes—to the current usage where an antibiotic is any medication that kills bacteria or inhibits their growth, regardless of whether it is naturally produced or synthetic.

Key Points

• 1

  Antibiotics are antimicrobial substances active against bacteria and may kill bacteria or inhibit their growth.

• 2

  In medicine, antibiotics are a specific important class of antibacterials, distinct from other synthetic antibacterials and disinfectants.

• 3

  Antibiotics are not effective against viruses or fungi, though a limited number may affect some protozoa.

• 4

  The modern definition of “antibiotic” includes medications that inhibit or kill bacteria, even if not produced by microorganisms.