抗生素英文课件精品 ANTIBIOTICS .ppt

ANTIBIOTICS
Inhibition of Protein Synthesis
Act either at:
* Site of protein synthesis (ribosome)
within the nucleus by inhibiting synthesis
of
nucleic acids
Increases permeability of membrane
External influences have greater effect Microbe death
Example: Polymyxin, Colistin
Note: These agents are more toxic systemically than those agents that inhibit cell wall synthesis.
synthesis 4. Inhibition of Protein
Synthesis 5. Interference with Metabolic
Processes
NB: Bactericidal Bacteriostatic
ANTIBIOTICS
Inhibition of Cell Wall Synthesis
*DNA replication / RNA synthesis = TRANSCRIPTION
Example: Tetracyclines, aminoglycosides and macrolides (erythromycin)
ANTIBIOTICS
Interference with metabolic processes
Example:Penicillins,cephalosporins, vancomycin and bacitracin
ANTIBIOTICS
Disruption of the microbial cell membrane
Affect cell membrane transportation in and out
x
ANTIBIOTICS
Carbapenems
Active mainly against gram -ve Eg,imipenem(tienem), ertapenem
(Invanz)
ANTIBIOTICS
cephalosporine
Active mainly against Gram +ve bacteria
3rd generation eg,cefoperazone(cefazone) ,sulperazone,cefdinir(dinar),cefotaxime (claforan),ceftriaxon(longacef)
ANTIBIOTICS
4th generation eg,cefipime(maxipime) ,ceftazidime(fortum)
Example: sulphonamides & trimethoprim
ANTIBIOTICS
Penicillins
Active mainly against gram +ve Eg.penicillin G,depo-
pen,meronem,ospen, Ampicillin,unasyn,augmentin,curam,flumo
ANTIBIOTICS
Aminoglycosides
Active against Gram –ve bacteria Eg, gentamicin(garamicin) ,amikacin
(amikin), neomycin ,vancomycin Nephrotoxicity and ototoxicity
*Mechanism of action
*Spectrum of Activity: ( broad or narrow)
Mechanism of Action:
1. Inhibition of Cell Wall Synthesis
2. Disruption of Cell Membrane 3. Inhibition of 来自百度文库ucleic acid
ANTIBIOTICS
Cephalosporins
1st generation eg,cephalexin(ceporex), cefadroxil(longicef),cefradine(velosef).
2nd generation eg,cefaclor(ceclor),cefuroxime(zinnat), cefixime(ximacef)
Agents which are structurally similar to paraaminobensoic acid (PABA) a component of folic acid essential for nucleic acid synthesis without it microbes can’t produce proteins for growth.
ANTIBIOTICS
Macrolides
Active against Gram +ve bacteria Bacteriostatic at low concentrations and
bactericidal at high concentrations Eg, erythromycin(erythrocin) ,azithromycin
(zisrocin) ,clarythromycin(klacid) ,clindamycin(dalacin c)
M.Raslan
ANTIBIOTICS
ANTIBIOTICS
Introduction
*Antibiotic is a natural substance produced by a micro-organism to kill another
ANTIBIOTICS
Classification
*Bacteriostatic (inhibit growth without death) or Bactericidial (Kill)