![Emaneini M. PhD.
Inhibition of Cell Wall Synthesis
Isoniazid, Ethionamide, Ethambutol, & Cycloserine
Used for the treatment of mycobacterial infections
Isoniazid
Isonicotinic acid hydrazide [INH])
Bactericidal; Blocks mycolic acid synthesis
Ethionamide
Derivative of INH
Blocks mycolic acid synthesis
Ethambutol
Interferes with the synthesis of arabinogalactan in the cell wall
Cycloserine
Inhibits D-alanine-Dalanine synthetase & Alanine racemase](https://image.slidesharecdn.com/antibioticslecture-210120181953/85/Antibiotics-lecture-7-320.jpg)
Antibiotics lecture
- 1. Emaneini M. PhD. The Spectrum of Antimicrobial Activity Narrow spectrum (limited spectrum) Antimicrobials effective against a (limited spectrum) of microbial types A drug effective on G+ or G- bacteria Broad spectrum (extended spectrum) Antimicrobials effective against a (extended spectrum) wide variety of microbial types A drug effective against both G+& G- bacteria
- 2. Emaneini M. PhD. The Action of Antimicrobial Drugs Bactericidal Kill microbes directly Bacteriostatic Prevent microbes from growing
- 3. Emaneini M. PhD. Mechanisms of Antibiotics Action
- 4. Emaneini M. PhD. 1- Inhibition of Cell Wall Synthesis 2- Injuring the Plasma Membrane 3- Inhibition of Protein Synthesis 4- Inhibition of Nucleic Acid Synthesis 5- Inhibiting the Synthesis of Essential Metabolites Mechanisms of Antibiotics Action
- 5. Emaneini M. PhD. Inhibition of Cell Wall Synthesis Transpeptidases, Carboxypeptidases, Transglycosylases Penicillin-binding proteins (PBPs( β-Lactam antibiotics: generally are bactericidal agents
- 6. Emaneini M. PhD. 1- Beta-Lactam Antibiotics Penicillins Cephalosporins 2- Glycopeptides Vancomycin 3- Lipopeptides Daptomycin 4- Polypeptides Bacitracin Inhibition of Cell Wall Synthesis
- 7. Emaneini M. PhD. Inhibition of Cell Wall Synthesis Isoniazid, Ethionamide, Ethambutol, & Cycloserine Used for the treatment of mycobacterial infections Isoniazid Isonicotinic acid hydrazide [INH]) Bactericidal; Blocks mycolic acid synthesis Ethionamide Derivative of INH Blocks mycolic acid synthesis Ethambutol Interferes with the synthesis of arabinogalactan in the cell wall Cycloserine Inhibits D-alanine-Dalanine synthetase & Alanine racemase
- 8. Emaneini M. PhD. Injuring the Plasma Membrane 1- Lipopeptides Daptomycin 2- Polypeptides Polymyxins
- 9. Emaneini M. PhD. Inhibition of Protein Synthesis
- 10. Emaneini M. PhD. Chloramphenicol Broad spectrum Bacteriostatic Blocking peptide elongation Binding reversibly to the peptidyl transferase (50S) Only for the treatment of typhoid fever Can produce aplastic anemia (1 per 24,000 treated patients) Resistance: plasmid-encoded chloramphenicol acetyltransferase
- 11. Emaneini M. PhD. Inhibition of Nucleic Acid Synthesis 1- Quinolones 2- Rifampin 3- Metronidazole
- 12. Emaneini M. PhD. Synthetic Inhibit bacterial DNA gyrases (II) or topoisomerases (IV) Nalidixic acid Fluoroquinolones: Ciprofloxacin Levofloxacin Gatifloxacin Resistance: mutations in chromosomal genes of DNA gyrases (II) or topoisomerases (IV) Quinolones
- 13. Emaneini M. PhD. Antimetabolites Sulfonamides Preventing the synthesis of the folic acid Compete with p-aminobenzoic acid Mammalian organisms do not synthesize folic acid Treatment of Nocardia, Chlamydia, & some protozoa infections Sulfacetamide Sulfadiazine Sulfisoxazole R Group