Part 2 Antibiotics Introduction
Antibiotics Overview
Introduction to Antibiotics
- Antibiotics are chemicals that inhibit specific bacteria, derived from living microorganisms or synthesized through genetic engineering.
- They can be classified as bacteriostatic (inhibiting growth) or bactericidal (killing bacteria).
Major Classes of Antibiotics
- Key classes include:
- Aminoglycosides
- Carbapenems
- Cephalosporins
- Fluoroquinolones
- Penicillin and penicillinase-resistant drugs
- Tetracyclines
- Antitubercular and leprostatic drugs
- Other antibiotics mentioned: ketolides, lincosamides, lipoglycopeptides, macrolides, monobactams, oxazolidinones, and vancomycin.
Routes of Infection and Immune Response
- Bacteria can invade the body through various routes including gastrointestinal, respiratory, and skin.
- The human inflammatory response is activated upon infection, leading to symptoms as the body attempts to eliminate foreign cells.
Importance of Antibiotic Therapy
- The goal of antibiotic therapy is to reduce the bacterial population so that the immune system can effectively combat the invaders. This applies universally across infections.
Diagnostic Methods for Infections
- Samples such as sputum or tissue are analyzed for bacteria using gram staining techniques.
- Gram-positive bacteria retain stain (e.g., Streptococcus pneumoniae causing pneumonia), while gram-negative bacteria lose it (e.g., E. coli causing cystitis).
Aerobic vs Anaerobic Bacteria
- Aerobic bacteria require oxygen for survival; anaerobic do not depend on oxygen. Understanding this distinction is crucial in selecting appropriate antibiotics.
Selecting Appropriate Antibiotics
- The choice of antibiotic should target the causative organism with minimal adverse effects.
- Broad-spectrum antibiotics may be used initially until specific organisms and sensitivities are identified.