🔬 Introduction to Antibiotics
Antibiotics are chemical substances produced by microorganisms or synthesized artificially to kill or inhibit the growth of bacteria. They are crucial in treating bacterial infections but are ineffective against viral infections.
🧪 History of Antibiotics
- 1928 – Discovery of Penicillin by Alexander Fleming from the mold Penicillium notatum.
- 1940s – Antibiotics became widely used, revolutionizing modern medicine.
- Golden Age – Between 1940 and 1960, many new antibiotics were discovered.
🔍 Classification of Antibiotics
1. Based on Spectrum of Activity
- Broad-spectrum: Effective against a wide range (e.g., Tetracycline).
- Narrow-spectrum: Target specific bacteria (e.g., Penicillin G).
2. Based on Mode of Action
- Inhibit Cell Wall Synthesis: Penicillin, Cephalosporin.
- Inhibit Protein Synthesis: Streptomycin, Tetracycline.
- Inhibit Nucleic Acid Synthesis: Rifampin, Quinolones.
- Disrupt Cell Membrane: Polymyxins.
3. Based on Origin
- Natural: Penicillin (from mold).
- Semi-synthetic: Ampicillin.
- Synthetic: Sulfonamides.
🦠 Commonly Used Antibiotics
| Antibiotic | Source | Target |
|---|---|---|
| Penicillin | Penicillium notatum | Gram-positive bacteria |
| Streptomycin | Streptomyces griseus | Tuberculosis bacteria |
| Tetracycline | Streptomyces aureofaciens | Broad-spectrum |
| Erythromycin | Streptomyces erythraeus | Respiratory infections |
💊 Uses of Antibiotics
- Treat bacterial infections (e.g., pneumonia, tuberculosis, UTI).
- Prevent infections during surgery.
- Used in animal husbandry to promote growth and prevent disease.
⚠️ Side Effects of Antibiotics
- Allergic reactions (rash, anaphylaxis).
- Diarrhea and gastrointestinal discomfort.
- Fungal infections due to loss of good bacteria.
🧬 Antibiotic Resistance
Overuse and misuse of antibiotics lead to resistance, making bacteria no longer respond to treatment. Major concerns include:
- MRSA (Methicillin-resistant Staphylococcus aureus)
- MDR-TB (Multi-drug-resistant Tuberculosis)
📝 Tips for Responsible Antibiotic Use
- Only use antibiotics prescribed by a doctor.
- Complete the full course.
- Avoid using leftover or shared antibiotics.