Antibiotics workshop

• T or F Clavulanic acid inhibits all beta lactamases?

  false
• which of the following is a natural penicillin?

  • penicillin A
  • penicillin F
  • penicillin G
  • penicillin T

  Penicillin G
• what is a natural penicillin?


  • natural penicillins are also called 1st generation penicillins
  • derived from penicillium fungi
  • first antibiotics used and good against many bacteria like streptococcus and staphylococcus
• what are the two types of natural penicillins?


  • penicillin G - benzylpenicilliins
  • penicillin V - phenoxymethylpenicillin
• which antibiotic is given empirically in bacterial meningitis?

  benzylpenicillin
• Gray baby syndrome is the adverse reaction to which antibiotic?

  Chloramphenicol
• what is gray baby syndrome? what characterises it?


  when neonates are given chloramphenicol and suffer an adverse reaction which is characterised by abdominal distention, haemodynamic collapse and an ashen-gray skin discolouration
• what is the MIC for MRSA with oxacillin and vancomycin (intermediate and resistant)?

  • oxacillin MIC >2 mg/L
  • MIC 4–8 mg/L
  • ≥16 mg/L,
• Aside from inactivation of antibiotic by Beta Lactamase, how else does penicillin resistance occur?

  alteration in target PBPs
• T or F: ceftriaxone is a third generation cephalosporin?

  true
• what class of antibiotic is aztreoname?

  monolactams
• what is a monobactam?


  • antibiotic with only one beta lactam ring, not fused with another ring
  • effective against gram negative bacteria
• what is the MOA of vancomycin?

  • bactericidal action
  • inhibition of cell-wall biosynthesis
  • prevents incorporation of N-acetylmuramic acid (NAM)- and N-acetylglucosamine (NAG)-peptide subunits from being incorporated into the peptidoglycan matrix - the major structural component of Gram-positive cell walls
  • Vancomycin forms hydrogen bonds with the terminal D-alanyl-D-alanine moieties of NAM/NAG-peptides, preventing incorporation of NAM/NAG-peptide subunits into peptidoglycan matrix.
  • Also vancomycin alters bacterial-cell-membrane permeability and RNA synthesis
• which of the following is an adverse effect of Vancomycin?

  • green skin syndrome
  • yellow eye syndrome
  • red man syndrome
  • blue blood syndrome

  red man syndrome
• what is red man syndrome? also known as vancomycin flushing syndrome

  VFS consists of a pruritic, erythematous rash of the face, neck, and upper torso, which may also involve the extremities, though to a lesser degree. Symptoms may include weakness, angioedema, and chest or back pain

  usually the vancomycin has been infused rapidly

  
• Which of the following is NOT a contributing factor to antibiotic resistance?

  • genetic mutations in bacteria
  • poor infection control practices
  • overuse and misuse of antibiotics
  • correct disposal of antibiotics

  correct disposal of antibiotics
• which of the following is not an aminoglycoside?

  • gentamicin
  • vancomycin
  • tobramycin
  • amikacin

  vancomycin - is a glycopeptide antibiotic rather than an aminoglycoside
• which of the following is an example of an efflux pump contributing to antibiotic resistance?

  • PBP mutation in MRSA
  • Tet(X) enzyme in tetracycline-resistant bacteria
  • Beta-lactamase production in Gram-negative bacteria
  • pseudomonas aeruginosa MexAB-OprM

  Pseudomonas aeruginosa MexAB-OprM
• what is MexAB-OprM?


  MexAB-OprM is a multidrug efflux protein expressed in the Gram-negative Pseudomonas aeruginosa. 

  antibiotics are effluxed out of the cell, including quinolones, macrolides, novobiocin, chloramphenicol, tetracyclines, lincomycin, and β-lactam antibiotics
• is Nalidixic Acid is a Fluoroquinolone ?


  no it is a synthetic quinolone
• what does MIC mean in antibiotic susceptibility testing

  minimum inhibitory concentration
• which drug has a side effect of orange body fluids?


  Rifampicin
• What type of bacterium is MRSA?

  • gram positive coccus in clusters
  • gram negative rods
  • gram negative diplococcus
  • gram positive cocci in chains

  gram positive coccus in clusters
• what is meant by antibiotic stewardship?


  A program promoting the appropriate use of antibiotics
• what is the clinical indication for nitrofurantoin?

  • skin infection by MRSA
  • typhoid fever by salmonella typhi
  • primary M. tuberculosis
  • UTI by E.coli and Enterococci spp


  UTI by e.coli and enterococci spp.
• what does ESBL sand for in beta lactams?

  extended spectrum beta lactamases
• make sure to go and check the flash cards!!


  go to physical flashcards ❤️
• give examples of drugs against ESBL

  carbapenems

  nitrofurantoin

  beta lactamase inhibitors (clauvanic acid)

  fosfomycin

  cephamycin