Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

2.ANTIBIOTIC (CELL WALL INHIBITORS)

13,096 views

Published on

The most common mode of action for antibiotics is the inhibition of cell wall synthesis. Antibiotics that inhibit cell wall synthesis work because of the fact that most eubacteria have peptidoglycan-based cell walls but mammals do not. Growth is prevented by inhibiting peptidoglycan synthesis. Thus these antibiotics only work for actively growing bacteria. The cell wall of new bacteria that grew in the presence of cell-wall-synthesis inhibitors is deprived of peptidoglycan. These bacteria will be subjected to osmotic lysis.In addition, gram-negative bacteria generally are less susceptible to inhibitors of cell wall synthesis than are gram-positive bacteria. In the former cell wall synthesis inhibitors fail to reach the cell wall because they are blocked by the gram-negative outer membrane.Penicillin is the classic example of an inhibitor of cell wall synthesis. Other examples include: ampicillin, bacitracin, carbapenems, cephalosporin, methicillin, oxacillin and vancomycin

Published in: Health & Medicine
  • Be the first to comment

2.ANTIBIOTIC (CELL WALL INHIBITORS)

  1. 1. BYBY Dr.Dr. SAMINATHAN KAYAROHANAMSAMINATHAN KAYAROHANAM M.PHARM, M.B.A, PhDM.PHARM, M.B.A, PhD ANTIBIOTIC (CELL WALL INHIBITORS ) 1 2
  2. 2. 2 NUM CONTENT SLIDE 1 OVERVIEW OF PENICILLIN 4 2 DEFINITIONS 5 3 THE SPECTRUM OF ANTIBIOTIC ACTIVITY 6 4 COMMON BACTERIA BY SITE OF INFECTION 7,8 5 DRUG,PRIMARY EFFECTS,SPECTRUM AND SIDE EFFECTS 9 6 GENERAL MECHANISAM OF ANTIBIOTICS 10 7 CLASSIFICATION OF CELL WALL INHIBITORS 11 8 CLASSIFICATION OF PENICILLIN 12-14 9 STRUCTURAL FEATURES OF β-LACTAM ANTIBIOTICS 15 10 MECHANISM OF ACTION OF PENICILLINS 16,17 11 ADVERSE EFFECTS OF PENICILLINS 18,19 12 THERAPEUTIC APPLICATIONS 20-22 13 INTRODUCTION TO CEPHALOSPORINS 23 14 THERAPEUTIC APPLICATIONS OF CEPHALOSPORINS 24
  3. 3. 3 LEARNING OUTCOME 1. Able to understand and describe various definition related to antibiotics 2. Describe the common bacteria, types of infection and the treatment. 3. Abele to demonstrate the general mechanism of antibiotics and classification of cell wall inhibitors. 4. Able to describe the penicillin mechanism and adverse effects. 5. Able to understand the therapeutic application of cell wall inhibitors.
  4. 4. 4 1. OVERVIEW OF PENICILLIN Antibiotics or Antibacterials are a type of antimicrobial used in the treatment and prevention of bacterial infection. They may either kill or inhibit the growth of bacteria. The penicillin is naturally produced by fungi of the genus Penicillium. Penicillin is a common antibiotic, used to treat bacterial infections. Penicillin was discovered by Scottish scientist Sir Alexander Flemingin 1928. Bactericidal An antimicrobial drug that can eradicate an infection in the absence of host defense mechanisms; kills bacteria. Bacteriostatic An antimicrobial drug that inhibits microbial growth but requires host defense mechanisms to eradicate the infection; does not kill bacteria. Beta-lactam antibiotics Drugs with structures containing a beta- lactam ring: includes the penicillins, cephalosporins and carbapenems. This ring must be intact for antimicrobial action. Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  5. 5. 2. DEFINITIONS 5 Beta-lactamases Bacterial enzymes (penicillinases, cephalosporinases) that hydrolyze the beta-lactam ring of certain penicillins and cephalosporins. Beta-lactam inhibitors Potent inhibitors of some bacterial beta- lactamases used in combinations to protect hydrolyzable penicillins from inactivation. Penicillin-binding proteins (PBPs) Bacterial cytoplasmic membrane proteins that act as the initial receptors for penicillins and other beta-lactam antibiotics. Peptidoglycan Chains of polysaccharides and polypeptides that are cross-linked to form the bacterial cell wall. Selective toxicity More toxic to the invader than to the host; a property of useful antimicrobial drugs. Transpeptidases Bacterial enzymes involved in the cross- linking of linear peptidoglycan chains, the final step in cell wall synthesis. Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  6. 6. 6 3.THE SPECTRUM OF ANTIBIOTIC ACTIVITY 6Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  7. 7. 7 4.COMMON BACTERIA BY SITE OF INFECTION Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  8. 8. 8 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  9. 9. 9 5.DRUG,PRIMARY EFFECTS,SPECTRUM AND SIDE EFFECTS 99Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  10. 10. 6.GENERAL MECHANISAM OF ANTIBIOTICS 10 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  11. 11. 11 7.CLASSIFICATION OF CELL WALL INHIBITORS 1111 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  12. 12. 12 1.Natural Penicillins: •Aqueous penicillin G •Penicillin G •Penicillin VK 2.Beta lacatamse resistant Penicillins •Methicillin •Nafcillin •Oxacillin •Cloxacillin •Dicloxacillin 3. Aminopenicillins /extended spectrum •Ampicillin •Amoxicillin 4. Carboxypenicillins/ antipseudomonal penicillins /extended spectrum •Carcenicillin •Ticarcillin 5. Ureidopenicillins / antipseudomonal penicillins / extended spectrum •Mezlocillin •Piperacillin 6. Penicillins/inhibitor combination •Ampicillin/sulbactam •Ticarcillin/clavulanate •Piperacillin/tazobactam •Amoxicillin/clavulanate 8.CLASSIFICATION OF PENICILLIN Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  13. 13. PHARMACOKINETIC PARAMETERS OF SELECTED PENICILLINS 13 Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  14. 14. 14 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  15. 15. 15 PENICILLINS The penicillin's are among the most widely effective antibiotics and also the least toxic drugs known, but increased resistance has limited their use. Members of this family differ from one another in the R substituent attached to the 6-aminopenicillanic acid residue. The nature of this side chain affects the antimicrobial spectrum, stability to stomach acid, and susceptibility to bacterial degradative enzymes (β- lactamases). 9.STRUCTURAL FEATURES OF Β -LACTAM ANTIBIOTICS Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  16. 16. 10. MECHANISM OF ACTION OF PENICILLINS 16 1.Penicillin-binding proteins: Penicillins inactivate numerous proteins on the bacterial cell membrane. These penicillin-binding proteins (PBPs) are bacterial enzymes involved in the synthesis of the cell wall and in the maintenance of the morphologic features of the bacterium. 2.Inhibition of transpeptidase: Penicillins inhibit this transpeptidase-catalyzed reaction, thus hindering the formation of cross-links essential for cell wall integrity. As a result of this blockade of cell wall synthesis. 3.Production of autolysins: Many bacteria, particularly the gram-positive cocci, produce degradative enzymes (autolysins) that participate in the normal remodeling of the bacterial cell wall.   Con… 16 Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  17. 17. 17 1- Penicillin (or other cell wall synthesis inhibitor) is added to the growth medium. 2- The cell begins to grow, but is unable to synthesize new cell wall. 3- cytoplasm covered by plasma membrane begins to squeeze out through the gap(s) in the cell wall. 4- Cell wall integrity is further violated. The cell continues to increase in size, but is unable to "pinch off" the extra cytoplasmic material into two daughter cells . 5- The loss of the cell wall also causes the cell to lose control over its shape, Finally, the fact that the cell disrupts homeostasis, which usually leads to the cell's death 10. MECHANISM OF ACTION OF PENICILLINS Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  18. 18. 18 11. ADVERSE EFFECTS OF PENICILLINS Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  19. 19. 19 11. ADVERSE EFFECTS OF PENICILLINS Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  20. 20. 20 12. THERAPEUTIC APPLICATIONS Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  21. 21. 21 12.THERAPEUTIC APPLICATIONS OF PENICILLIN G. Con…Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  22. 22. 22 12. ANTIMICROBIAL SPECTRUM OF IMIPENEM Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  23. 23. 13. INTRODUCTION TO CEPHALOSPORINS 23 These β-lactam antibiotics are also fungal products and have bactericidal activity due to inhibition of transpeptidase. The cephalosporins are β-lactam antibiotics that are closely related both structurally and functionally to the penicillins. Most cephalosporins are produced semisynthetically by the chemical attachment of side chains to 7- aminocephalosporanic acid. Cephalosporins are acid stable, but many are poorly absorbed. Cephalosporins are penicillinase-resistant. Cephalosporins are broad-spectrum antibacterials. Cephalosporins are mostly well tolerated. All can cause allergic reactions, some cause renal injury, alcohol intolerance, and bleeding (vitamin K antagonism). Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D
  24. 24. 24 14.THERAPEUTIC APPLICATIONS OF CEPHALOSPORINS Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

×