抗生素作用机制（英文PPT）Antibiotics that Inhibit Cell Wall SynthesisPPT.ppt

Mechanisms of Antibiotic Function I;Please Read The relevant chapters on antibiotics in Goodman and Gilman or Langes Basic Clinical pharmacology (recommended);Antibiotics The term originally referred to any agent with biological activity against living organisms, as in “anti” against “biotics” life. Today Antibiotics are defined as agents that inhibit or abolish the growth of micro-organisms, such as bacteria, fungi, protozoa or parasites such as worms. We will focus on antibacterial agents alone They are the number 1most prescribed group of drugs.;What would define a perfect Antibiotic? 1. ? 2. ? 3. ? 4. ? 5. ? This is an important question!;What would define a perfect Antibiotic? Effectiveness. Does the drug eliminate the microbial threat. It can be bacteriostatic, or bacteriocidal. Bioavailability. Does the drug reach the target organ (blood brain barrier etc.) Specificity. Does the drug also eliminate normal flora? Narrow or broad spectrum? Side effects. Most antibiotics are not in use… they are lethal. Most current antibiotics have unwanted side effects. Pricing. 3rd world countries or even rich countrie Resistance. Can bacteria develop resistance? (Tetracycline fed to bovine for improved yield).;Lecture Plan;Cell wall synthesis is a process not found in humans so its inhibition is well tolerated. This is one of our most notable pharmacological success stories. Porin pores are important for drugs to cross the outer membrane of gram negative bacteria.;?-Lactams = penicillins and cephalosporins are most important Vancomycin = Blocks cell wall synthesis by other mechanisms and so helps handle resistance to ?-Lactams. Resistance = an alarming problem.;;;;;The Antimicrobial Drugs, p. 89;;;;;;Human Pharmacology: Molecular to Clinical, Brodie, T.M., et al. (1998) p. 658;The Antimicrobial Drugs, p. 92;The Antimicrobial Drugs, p. 92;Human Pharmacology: Molecular to Clinical, p. 657;Human Pharmacology: Molecular to Clinical, p. 657;MRSA;;Cephalos