Inhibitors of cell Wall Synthesis Semisynthetic Penicillins Penicilinase-resistant Carbapenems: broad spectrum o Monobactam Gram R-C-NH-CH--CH CH o=c—N C--CHo-0-C CH3 COOH Cephalosporins Cephalosporin nucleus 2nd, 3rd, and 4th generations more effective CH3 against G R-c—NH-cH-cHc CH3 o=c—N—cH-cooH
• Cephalosporins • 2nd, 3rd, and 4th generations more effective against GInhibitors of Cell Wall Synthesis Semisynthetic Penicillins Penicilinase-resistant Carbapenems: broad spectrum Monobactam: Gram-
Side chain: General Structure Of Penicillin Ampicillin B Cloxacillin CH Phenoxymethyl- Ticarcillin H B-lactam drugs β actamase(penicillinase) Peptide- glycan matrⅸx Penicillin-binding protein Rigid cell wall of Gram-positive bacteria 口B- lactam drugs Lipopolysacch aride layer Th in matrⅸ Penicillin-bindin g protein Gram-negative bacterial wall KMc 17
17
Penicillinase(B Lactamase produced by some bacteria --resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems (ertapenem) H OH Clavulanate OH (Clavulanic acid H O N sulbactam OH 10 cm H LO Penicillins B-lactamase inhibitors N (Clavulanate, sulbactam, and tazobactam tazobactam OH
Penicillinase (β Lactamase) -produced by some bacteria --resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems (ertapenem) Penicillins + β-lactamase inhibitors (Clavulanate, sulbactam, and tazobactam ) Clavulanate (Clavulanic acid) sulbactam tazobactam
Clavulanic acid B lactam(B lactamases inhibitor) binds strongly to B lactamases inhibits B lactamases activity -no direct effects on bacteria limited potency as antibiotic used in conjunction with other B lactams
• β lactam (β lactamases inhibitor) • binds strongly to β lactamases – inhibits β lactamases activity –No direct effects on bacteria • limited potency as antibiotic • used in conjunction with other β lactams Clavulanic acid 19
Disruption of the microbial cell membrane Essentially, affect cell membrane transportation in and out ncreases permeability of membrane External influences have greater effect Microbe death Y Detergent like: Polymyxin, Colistin Specific interfere with biosynthetic function of Cm novobiocin Y ionophores(cations ): Valinomycin-binds potassium ions Note: These agents are more toxic systemically than those agents that inhibit cell wall synthesis
Disruption of the microbial cell membrane • Essentially, affect cell membrane transportation in and out • Increases permeability of membrane – External influences have greater effect – Microbe death Detergent like: Polymyxin, Colistin Specific interfere with biosynthetic function of CM : novobiocin Ionophores (cations): Valinomycin –binds potassium ions Note: These agents are more toxic systemically than those agents that inhibit cell wall synthesis