Beta Lactum Antibiotics presentation.pptx

This presentation describes bacterial cell was destructive antibiotics or Beta Lactum Antibiotics.

1. Cell Wall Inhibitory Antibiotics Mechanisms, Structures, and Clinical Significance A Comprehensive Overview of Beta-Lactams Antibiotics MD ROBEL AHMED (2504112)

2. The Bacterial Cell Wall: An Essential, Unique, and Vulnerable Target Cell wall provides structural integrity , maintains cell shape, and protects against osmotic lysis in diverse environments. Without it, bacteria are highly vulnerable. Eukaryotic cells (human cells) lack a cell wall. This makes the bacterial cell wall an ideal selective target for antibiotics, minimizing host toxicity. Primary structural component of the bacterial cell wall is Peptidoglycan layer , a complex polymer of sugars and amino acids, crucial for its strength.

3. Major differences between Gram positive and negative

4. Beta-Lactam Antibiotics: The Cornerstone of Anti-Bacterial Therapy

5. Mechanism of Action: Beta Lactam Antibiotics

6. Subtype 1: Penicillins Core Structure: Characterized by the beta-lactam ring fused to a five-membered thiazolidine ring. The side chain (R group) attached to the beta-lactam ring determines the specific properties of each penicillin. Mechanism of Action: Penicillins bind irreversibly to Penicillin-Binding Proteins (PBPs) located in the bacterial cytoplasmic membrane. By mimicking the D-Ala-D-Ala portion of the peptidoglycan precursor, they inhibit the transpeptidation (cross-linking) step of cell wall synthesis, leading to a weak and unstable cell wall. Target Bacteria: Primarily effective against Gram-positive bacteria, though extended-spectrum penicillins have activity against some Gram-negative species.

7. Natural Penicillins : Examples: Methicillin, Nafcillin , **Oxacillin, Dicloxacillin. Spectrum:. Active against Staphylococcus aureus (excluding MRSA) and Streptococci. Extended-spectrum Penicillins (Aminopenicillins): Examples : Ampicillin , Amoxicillin. Spectrum: Broader Gram-negative coverage than natural penicillins , including Haemophilus influenzae, E. coli, Proteus mirabilis, Salmonella, and Shigella. Key Subtypes & Characteristics The modification of the R-group attached to the penicillin core allows for different antimicrobial spectra, pharmacokinetic properties, and resistance to beta-lactamase enzymes.

8. Key Penicillin and Their Trade Names in Details Penicillin G: Trade Names: Pfizerpen (IV), various generics. Uses: Syphilis, severe streptococcal infections (e.g., endocarditis, pharyngitis), meningococcal meningitis. Penicillin V: Trade Name: Pen-Vee K, Veetids . Uses: Oral treatment for mild to moderate streptococcal pharyngitis, skin infections. Nafcillin / Oxacillin: Trade Names: Unipen (Nafcillin, discontinued brand), Bactocill (Oxacillin, discontinued brand), various generics. Uses: Serious staphylococcal infections susceptible to methicillin (MSSA), osteomyelitis, endocarditis. Amoxicillin: Trade Name: Amoxil, Moxatag . Uses: Otitis media, sinusitis, bronchitis, uncomplicated urinary tract infections, H. pylori eradication. Ampicillin: Trade Name: Principen . Uses: Similar to amoxicillin, but also used for Listeria infections, enterococcal infections.

9. Subtype 2: Cephalosporins

10. Subtype 3: Carbapenems

11. Carbapenems (e.g., Meropenem) inhibit bacterial cell wall synthesis by binding strongly to penicillin-binding proteins (PBPs) . This blocks the cross-linking of peptidoglycan chains , which is essential for maintaining bacterial cell wall strength and rigidity. The result is cell wall weakening , osmotic instability , and rapid bacterial cell lysis . They are resistant to most beta-lactamases , allowing them to remain effective against many multidrug-resistant organisms. Mechanism of Action

12. 💊 Common Trade Names Meropenem – Merrem ® IV Imipenem + Cilastatin – Primaxin ® Ertapenem – Invanz ® Doripenem – Doribax ®

13. Comparison of beta-lactam ring structure across different classes of medications

14. END