Key boxes Flashcards
Name the 2 groups of β- lactam antibiotics
Penicillins and cephalosporins
What is the β-lactams mode of action
Inhibit cell wall synthesis
Give examples of glycopeptides and how they function
Vancomycin and telicoplanin.
Act on different stage of cell wall synthesis to β-lactams
What do glycopeptides act on?
gram positive organisms
Give a downside of Vancomycin
Toxic - hearing, brain and skin rashes.
What class of antibiotics are useful in treating serious Gram negative infections eg. coliform
Aminoglycosides, eg. gentamicin
Give a downside of gentamicin
toxic - requires careful dosing regime and monitoring of levels
Describe ciprofloxacin
Inhibits DNA synthesis
Effective against gram negative organisms and can be taken orally.
Can’t be used in children.
Describe the two important mechanisms of resistance to β-lactam antibiotics
1) Produce β-lactamase, an enzyme that cleaves off the β-lactam ring of the antibiotic and render it inactive.
2) Alter structure of the Penicillin binding protein target site.
Name an organism that can produce β-lactamase
Staph-aureus
Name an antibiotic that is β-lactamase resistant and can be used to treat staph. aureus
Flucloxacillin
Name an organism that have genetically altered target sites to which β-lactams can’t bind
MRSA - resistant to all penicillins and cephalosporins
What can some gram negative organisms produce that renders then resistant to all β-lactam agents
ESBLs (extended spectrum β-lactamases)
Name a bacteria resistant to Vancomycin
Vancomycin resistant enterococci (VRE)
Resistance is unusual in gram positive organisms
Give an important side effect of antibiotic therapy
Clostridium difficile infection (CDI)
