Week 1 Antibiotics: Cell Wall ✅ Flashcards
What are the 3 antibiotic target sites?
Cell wall
DNA
Protein synthesis in ribosomes
What are the 3 cell wall group antibiotics?
β-lactams
Vancomycin
Bacitracin/Polymyxin
What are the 4 types of β-lactams?
Penicillins
Carbapenems
Cephalosporin
Monobactams
What is the difference between gram +ve and -ve?
Gram-ve has an extra layer of lipopolysaccharide
What are the layers of gram+ve bacteria?
Cytoplasm
Cell membrane
Peptidoglycan
What are the layers of gram-ve bacteria?
Cytoplasm
Cell membrane
Peptidoglycan
Lipopolysaccharide
What layer of bacteria stains in a gram stain?
Peptidoglycan
What is the function of peptidoglycan?
Determine shape and structure of the bacteria e.g. rod, cone, sphere
Cross-linked to provide strength
Are Penicillins more effective in gram+ve or -ve bacteria?
Gram +ve
What is the site of action of Penicillin?
Transpeptidase enzyme
How does Penicillin work? MOA in bacteria?
β-lactam ring binds to transpeptidase enzyme and inhibits the cross linking in the cell wall so it loses strength and cell membrane is exposed to osmotic damage
What is Pen G also known as?
Benzylpenicillin
What is Pen G used for?
Severe infection
How is Pen G administered?
Injection as degraded in the stomach
What is Pen V also known as?
Phenoxymethylpenicillin
What is Pen V used for?
Strep throat
How is Pen V administered?
Oral
What does streptococcal bacteria cause?
Pneumonia and endocarditis
What does clostridia bacteria cause?
Tetanus
What does meningococcal bacteria cause?
Meningitis and septicaemia
What is Amoxicillin used to treat?
Pneumonia, UTI, hospital-acquired pneumonia, H. pylori
Is Amoxicillin broad spec or narrow spec Penicillin?
Main broad spectrum - benefit includes doesn’t have to identify bacteria first
What is a side effect of Amoxicillin?
Diarrhoea - influences the gut biome
Can cause C. diff and colitis
Is Amoxicillin metabolised by the liver?
No
What is Flucloxacillin used to treat?
Skin infection
What is different about the structure of Flucloxacillin?
No β-lactam ring
What is β-lactamase?
Produced by bacteria to break β-lactam ring in Penicillin