Flashcards in Antibiotics 1 Deck (14)
What are the four types of beta-lactam antibiotics?
Penicillins, Cephalosporins, Carbapenems and Monobactams
What is the common structural feature of beta-lactams?
They have a beta-lactam ring
What is the mechanism of beta-lactam antibiotics?
They are transpeptidase inhibitors, and so inhibit the cross-linking of the backbone molecules of bacterial cell walls
What are the four main ways of bacteria producing resistance to an antibiotic?
1. Enhanced egress of the antibiotic (AB)
2. Inhibited ingress of the AB
3. Enzymatic destruction of the AB
4. Alteration of AB target
What do beta-lactamases do?
Inhibit the transpeptidase inhibitors of beta-lactam ABs
What are the four penicillinase resistant beta-lactams?
Methicillin, flucloxacillin, dicloxacillin and cephalexin
What do tazobactam and clavulanic acid do?
They are inhibitors of bacterial beta-lactamases. This means that when combined with beta-lactams, the AB spectrum of activity is increased against beta-lactam resistant bacteria
What are tazobactam/clavulanic acid combined with, to give Augmentin, Tazocin and Timentin?
Augmentin: amoxocillin + clavulanic acid
Tazocin: piperacillin + tazobactan
Timentin: ticarcillin + clavulanic acid
What does MRSA stand for, and what does it mean?
Methicillin resistant Staphylococcus aureus
This means Staph is resistant to beta-lactams + flucloxacillin. It has developed a new gene for transpeptidases, reducing beta-lactam binding
What would you use to treat an MRSA infection orally?
Erythromycin, clindamycin and tetracyline
What would you use to treat an MRSA infection intravenously?
How is antibiotic synergy used to treat bacterial endocarditis?
AB synergy allows combinations of ABs to treat bacteria that would otherwise be resistant to the ABs on their own. In bacterial endocarditis, penicillin is combined with Gentamicin. Penicillin opens the bacterial cell wall, allowing gentamicin to get in to the bacteria and kill it
Which bacteria does flucloxacillin cover?
Stapha and Strep