Microbiology 20: Antimicrobials 1 Flashcards
What coverage do Glycopeptides antibiotics have ?
Gram +ve
When would Glycopeptide antibiotics be indicated ?
Gram +ve bacteria resistant to Beta lactams
E.g MRSA
Why are beta lactams considered bactericidal ?
They dont kill existing bacteria, they inhibit cell wall synthesis so stop new bacteria from forming their cell walls and hence causing lysis.
Give 3 examples of classes of beta lactams ?
Penicillins
Cephalosporins
Carbapenems
Give an example of a drug that is a beta lactamase inhibitor ?
Clavulanic acid
tazobactam
As you go up the generations of cephalosporins what happens to their activity against gram +ve and -ve bacteria ?
As you go up the generations the activity against gram -ve goes up and +ve goes down.
What complications can glycopeptides cause ?
Nephrotoxicity
Give 2 examples of Glycopeptides ?
Vancomycin
Teicoplanin
Which Glycopeptide is often used to treat C.difficile infection ?
Vancomycin
Which antibiotic is commonly used to treat meningitis ?
Ceftriaxone (cephalosporin)
Can’t normally penetrate blood brain barrier but does so when there is inflammation ie in meningitis
List 5 classes of Protein synthase inhibitors ?
Aminoglycosides Tetracyclines Macrolides Chloramphenicol Oxazolidinones (Linezolid)
Why are Proteinase inhibitors selective for bacteria and not hum an cells ?
They bind to the ribosomal subunit which is a different size in bacteria (30S) compared to human cells
What antibiotic coverage do Aminoglycosides (gentamicin) have ?
Good gram -ve activity
Poor gram +ve and anaerobe activity
what antibiotic coverage do Tetracyclines (doxycycline) have ?
Mostly gram +ve
Very good for intracellular pathogens e.g chlamydia and mycoplasma
Which class of Protein synthesis inhibitors are contraindicated in children and pregnant women ?
Tetracyclines
Deposit in bone and also cause discolouration of teeth
Chloramphenicol is contraindicated in the 3rd trimester as it can cause “grey baby syndrome”
