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14: Antibiotics

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    144192
    • Ying Liu, Serena Chang, Grace Murphy, Esther Ajayi-Akinsulire, Isobel Ardren, Izabella Guy, Kai Johnston, Saskia Lee, and Lauren Russell
    • City College of San Francisco

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    In nature, some microbes produce substances that inhibit or kill other microbes that might otherwise compete for the same resources. Humans have successfully exploited these abilities, using microbes to mass-produce substances that can be used as antimicrobial drugs. Since their discovery, antimicrobial drugs have saved countless lives, and they remain an essential tool for treating and controlling infectious disease. But their widespread and often unnecessary use has had an unintended side effect: the rise of multidrug-resistant microbial strains. In this chapter, we will discuss how antimicrobial drugs work, why microbes develop resistance, and what health professionals can do to encourage responsible use of antimicrobials.

    Old poster stating: Penicillin - The new life saving drug saves soldier’s lives! Men who might have died will live if you give this job everything you’ve got. A person wearing personal protective gear sets up an intravenous bag full of fluid.
    Figure \(\PageIndex{1}\): First mass produced in the 1940s, penicillin was instrumental in saving millions of lives during World War II and was considered a wonder drug.1 Today, overprescription of antibiotics (especially for childhood illnesses) has contributed to the evolution of drug-resistant pathogens. (credit left: modification of work by Chemical Heritage Foundation; Credit right: DFID / Flickr; CC-BY)

    • 14.1: Discovering Antimicrobial Drugs
      Antimicrobial drugs produced by purposeful fermentation and/or contained in plants have been used as traditional medicines in many cultures for millennia. The purposeful and systematic search for a chemical “magic bullet” that specifically target infectious microbes was initiated by Paul Ehrlich in the early 20th century. The discovery of the natural antibiotic, penicillin, by Alexander Fleming in 1928 started the modern age of antimicrobial discovery and research.
    • 14.2: Fundamentals of Antimicrobial Therapy
      Antimicrobial drugs can be bacteriostatic or bactericidal, and these characteristics are important considerations when selecting the most appropriate drug. The use of narrow-spectrum antimicrobial drugs is preferred in many cases to avoid superinfection and the development of antimicrobial resistance. Broad-spectrum antimicrobial use is warranted for serious systemic infections when there is no time to determine the causative agent or when narrow-spectrum antimicrobials fail.
    • 14.3: Inhibitors of Cell Wall Biosynthesis
      Antibacterial compounds exhibit selective toxicity, largely due to differences between prokaryotic and eukaryotic cell structure. Cell wall synthesis inhibitors, including the β-lactams, the glycopeptides, and bacitracin, interfere with peptidoglycan synthesis, making bacterial cells more prone to osmotic lysis. There are a variety of broad-spectrum, bacterial protein synthesis inhibitors that selectively target the prokaryotic 70S ribosome, including those that bind to the 30S and 50S subunits.
    • 14.4: Inhibitors of Protein Synthesis
      Antibacterial compounds exhibit selective toxicity, largely due to differences between prokaryotic and eukaryotic cell structure. Cell wall synthesis inhibitors, including the β-lactams, the glycopeptides, and bacitracin, interfere with peptidoglycan synthesis, making bacterial cells more prone to osmotic lysis. There are a variety of broad-spectrum, bacterial protein synthesis inhibitors that selectively target the prokaryotic 70S ribosome, including those that bind to the 30S and 50S subunits.
    • 14.5: Other Antibiotics
      Antibacterial compounds exhibit selective toxicity, largely due to differences between prokaryotic and eukaryotic cell structure. Cell wall synthesis inhibitors, including the β-lactams, the glycopeptides, and bacitracin, interfere with peptidoglycan synthesis, making bacterial cells more prone to osmotic lysis. There are a variety of broad-spectrum, bacterial protein synthesis inhibitors that selectively target the prokaryotic 70S ribosome, including those that bind to the 30S and 50S subunits.
    • 14.E: Antimicrobial Drugs (Exercises)

    Footnotes

    1. 1 “Treatment of War Wounds: A Historical Review.” Clinical Orthopaedics and Related Research 467 no. 8 (2009):2168–2191.

    Thumbnail: Staphylococcus aureus - Antibiotics Test plate. (Public Domain; CDC / Provider: Don Stalons).

    This page titled 14: Antibiotics is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Ying Liu, Serena Chang, Grace Murphy, Esther Ajayi-Akinsulire, Isobel Ardren, Izabella Guy, Kai Johnston, Saskia Lee, and Lauren Russell via source content that was edited to the style and standards of the LibreTexts platform.