17 Questions
What is the mechanism of action of tetracyclines?
Preventing binding of amino-acyl transfer RNA (tRNA) to the ribosome
Which statement about tigecycline is true?
It retains activity against many bacteria susceptible to other tetracyclines
What is the main limitation that resistance has imposed on tetracyclines?
Limited value against many Gram-positive and Gram-negative bacteria
Which antibiotic acts by interfering with the action of bacterial dihydrofolate reductase?
Trimethoprim
What is the enzyme that catalyzes the last step of bacterial folic acid synthesis?
Dihydrofolate reductase
Which bacterial species are usually susceptible to tetracyclines despite resistance seen in others?
Chlamydia, rickettsia, and mycoplasmas
Which antibiotic is a structural analog of para aminobenzoic acid (PABA) and competes with it to bind to dihydropterote synthetase?
Sulfonamides
What is a notable side effect associated with aminoglycosides?
Nephrotoxicity
Which antibiotics exhibit potent antipseudomonal activity but have limited usefulness due to toxicity?
Polymyxins
What type of effect arises between sulphonamides and trimethoprim when used in combination?
Synergistic effect
Which antibiotic has a role in the treatment of infections caused by multidrug-resistant organisms?
Daptomycin
How do macrolide antibiotics act?
By interfering with the translocation of mRNA on the bacterial ribosome (binding to the 50S ribosome)
What is the mechanism of action of chloramphenicol?
Blocking the growth of peptide chain
Which antibiotic has been limited in use due to the occurrence of rare but fatal side effects like aplastic anemia?
Chloramphenicol
What is the primary target of fusidic acid in bacterial cells?
Factor G involved in peptide elongation
Which organism is NOT sensitive to macrolide antibiotics?
Enteric Gram-negative bacilli
Resistance to antibiotics can arise from alterations in:
mRNA translocation on the bacterial ribosome
Learn about the differences between bacterial and mammalian ribosomes and how selective inhibition of protein synthesis can be achieved. Explore how antibiotics produced by Streptomyces spp. target bacterial ribosomes. Discover the effects of these agents on eukaryotic cells with mitochondrial ribosomes similar to bacteria.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
