Beta Lactams Antibiotics Flashcards
Why is the beta lactam antibiotics called beta lactam
Because they have a betalactam ring in their structure, which is attached to thiazolidine ring attached through an amide linkage
Name the classes of drugs that comes under beta LACTAM
Penicillin, CEPHALOSPORINS CAARBAPENEMS MONOBACTAM
What is the main reason for stability and rigidity in the bacterial cell wall?
Cross linkages between the NAM units
How is cross linkages between the NAM units are formed in bacterial cell wall?
The NAM units of the bacterial cell wall have pentamer of five peptide chains, the enzyme transpeptidase present in the bacterial cell wall cleaves the terminal D alanine of the peptide chain. The energy that is released from this cleavage is utilised for formation of cross linkages.
Explain the mechanism of action of beta Lactam antibiotics
Beta LACTAM antibiotics bind to the penicillin binding protein in the bacterial cell wall, which in turn inhibits transpeptidase enzyme located in the bacterial cell wall. Therefore, this inhibits cleavage of decline from the peptide chain due to which no energy is produced. This prevents cross linkage formation in the cell wall. The bacterial cell that is formed due to cell division of these susceptible bacteria is called as cell deficient bacteria. This cell deficient bacteria is hyper osmotic due to loss of cell wall. This causes swelling and burst of the bacterial cell. Therefore, the bacteria gets lied.
What type of action bactericidal or bacteriostatic action does the beta lactam antibiotics shows
Bactericidal
Beta lactam is more active against which type of bacteria either gram negative or gram positive
Beta LACTAM is more active against gram positive bacteria because gram positive bacterial cell wall has a thicker peptidoglycan layer of about more than 50 or hundred layers, thick
Penicillin is non-toxic to man or animals. Give reason.
Penicillin are the first discovered non-toxic antibiotics. These belong to class beta LACTAMS which mainly aim at inhibiting cell wall synthesis since peptidoglycan is a special part of bacterial cell wall, and also it is absent in human and animals
How does bacteria gain resistance against beta LACTAMS
There are four mechanisms in which bacteria gains resistance against beta LMS
1. Reduction in the membrane permeability which decreases influx and increases if flux of beta LACTAN antibiotics.
2. Production of beta LACTAMASE or penicillinase by the bacteria, which degrades the beta LACTAM ring and inactivates the antibiotic
3. altered penicillin binding proteins that lack the binding affinity for penicillin
Which mechanism of resistance is adapted only by gram negative bacteria?
Reduction of membrane permeability which called decreases influx and increases effluent of beta AM antibiotics
Which mechanism of resistance is adapted by both gram and gram bacteria
Production of beta lacatamase or penicillinase
Which mechanism of resistance is adapted by staphylococcus aureus
Altered penicillin binding protein
Against which antibiotic the staphylococcus aureus is a resistant to
MRSA met hill in resistant staph aureus
Which was the first antibiotic to be discovered and by whom
The first antibiotic to be discovered was penicillin. It was discovered by Alexander Fleming, who was known as father of antibiotics.
What is the source of penicillin?
Penicillin was first obtained from a fungus penicillium notatum and presently the source and high yielding source for penicillin is penicillium. CHRYSOGENUM.
Mention the classification of penicillin
- natural penicillin, example, benzyl penicillin or penicillin G
- Semisynthetic penicillin further sub divided into acid resistant alternative to penicillin, G exampl phenoxy methyl penicillin
3.Penicillinase resistance penicilline eg. CONDoM - CLOXACILLIN, OXACILLIN, NAFCILLIN, DICLOXACILLIN, METHICILLIN - extended spectrum - three typesamino penicillins- eg, AMPICILLIN, AMOXICILLIN , BACAMPICILLIN
UERIDO PENICILLINASE. EG, PIPERACILLIN
CARBOXYPENICILLIN EG. CARBENICILLIN - Beta LACTAMASE inhibitors eg. CAVULANIC ACCID SULBACTAM. TAZOBACTAM
