Antibiotics are a class of antimicrobial drugs focused on killing bacteria.
They have revolutionized medicine by significantly reducing deaths from infectious diseases.
A century ago, 1 in 3 children died from infectious diseases before age 5.
Antibiotics have contributed to increased life expectancy, especially in wealthier countries.
Impact in Developing Regions
In poorer countries, high death rates from infections still persist.
Studies show that administering antibiotics can cut infant mortality rates by up to 25%.
Caution against prophylactic antibiotic use due to rising antibiotic resistance.
Nature and Source of Antibiotics
Antibiotics are small molecules, often produced by molds (e.g., penicillium) and bacteria (e.g., Actinomycetes) to protect themselves by killing other bacteria.
They engage in 'chemical warfare,' inhibiting bacterial growth on nutrient agar plates.
Selective Toxicity
Key feature: kill bacteria without harming the host.
Human cells: eukaryotic, have 80S ribosomes, nucleus, mitochondria.
Bacterial cells: prokaryotic, have 70S ribosomes, no nucleus.
Antibiotics target specific bacterial features, minimizing harm to human cells.
Early Discoveries and Development
Professor Ehrlich: Developed salversan, an early drug for syphilis, though toxic.
Alexander Fleming: Discovered penicillin in 1928 from penicillium mold.
1940-1945: Flory and Chain conducted clinical trials; Fleming, Flory, and Chain received the Nobel Prize in 1945.
Antibiotics in World War II
Penicillin was crucial in reducing soldier deaths from infections in WWII.
Government support accelerated penicillin production due to wartime needs.
Timeline of Antibiotic Discovery
Sulfonamides: First synthetic antibiotics discovered in the lab.
Post-1945 development led to several antibiotics in clinical use by the 1950s.
Conclusion
The lecture will continue with videos and discussion on broad categories of antibiotics.
Notes
Antibiotics are often called the 'magic bullet' for their ability to target harmful bacteria without damaging human cells.
The transition from the pre-antibiotic era to an antibiotic era was rapid, influenced by both scientific discovery and global events like WWII.
The history of antibiotics highlights the importance of careful introduction and regulation of new drugs to avoid resistance.