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Questions and Answers
Which bacterial enzyme is responsible for the cross-linking of peptidoglycan molecules in the cell wall?
Which bacterial enzyme is responsible for the cross-linking of peptidoglycan molecules in the cell wall?
In what phase are penicillins bactericidal?
In what phase are penicillins bactericidal?
Which class of penicillins is effective against gram-positive organisms and remains useful if the bacteria produce penicillinase?
Which class of penicillins is effective against gram-positive organisms and remains useful if the bacteria produce penicillinase?
Which drug is an irreversible inhibitor of many bacterial β-lactamases?
Which drug is an irreversible inhibitor of many bacterial β-lactamases?
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Why can high doses of penicillins lead to neurotoxicity?
Why can high doses of penicillins lead to neurotoxicity?
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What is the most common adverse effect of penicillins?
What is the most common adverse effect of penicillins?
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Which antibiotic has significant activity against anaerobes?
Which antibiotic has significant activity against anaerobes?
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What is the specific inhibitor of renal peptidase that prolongs the half-life of imipenem and limits renal toxicity?
What is the specific inhibitor of renal peptidase that prolongs the half-life of imipenem and limits renal toxicity?
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Which antibiotic can cause tissue necrosis if given intramuscularly?
Which antibiotic can cause tissue necrosis if given intramuscularly?
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What is the broad-spectrum antibiotic that is effective against gram-positive organisms, including MRSA?
What is the broad-spectrum antibiotic that is effective against gram-positive organisms, including MRSA?
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Which antibiotic is specifically NOT effective against Pseudomonas aeruginosa?
Which antibiotic is specifically NOT effective against Pseudomonas aeruginosa?
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Which antibiotic may lead to risk of fetal harm and nephrotoxicity?
Which antibiotic may lead to risk of fetal harm and nephrotoxicity?
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What is the main characteristic of β-lactam antibiotics in terms of their selectivity?
What is the main characteristic of β-lactam antibiotics in terms of their selectivity?
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What is the mechanism of action of penicillins?
What is the mechanism of action of penicillins?
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Why are β-lactam antibiotics able to selectively target bacteria?
Why are β-lactam antibiotics able to selectively target bacteria?
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What is the primary target of β-lactam antibiotics within bacterial cells?
What is the primary target of β-lactam antibiotics within bacterial cells?
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Which cellular feature makes β-lactam antibiotics ineffective against mammalian cells?
Which cellular feature makes β-lactam antibiotics ineffective against mammalian cells?
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What is the key factor contributing to the high selectivity of β-lactam antibiotics for bacteria over human cells?
What is the key factor contributing to the high selectivity of β-lactam antibiotics for bacteria over human cells?
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Which antibiotic binds to the P site of the 50S bacterial ribosomal subunit and blocks protein synthesis when a large amino acid or a polypeptide is in the P site?
Which antibiotic binds to the P site of the 50S bacterial ribosomal subunit and blocks protein synthesis when a large amino acid or a polypeptide is in the P site?
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Which macrolide antibiotic is much better absorbed after oral administration than erythromycin?
Which macrolide antibiotic is much better absorbed after oral administration than erythromycin?
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Which macrolide antibiotic has the most unusual property of uptake into several tissues, maintaining high concentrations for prolonged periods?
Which macrolide antibiotic has the most unusual property of uptake into several tissues, maintaining high concentrations for prolonged periods?
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Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
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Which antibiotics bind to the 50S ribosomal subunit at or near the erythromycin site and have excellent activity against anaerobic bacteria?
Which antibiotics bind to the 50S ribosomal subunit at or near the erythromycin site and have excellent activity against anaerobic bacteria?
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Which antibiotic preferentially binds to the 30S subunit of the microbial ribosome, interfering with binding of amino acyl-tRNA and inhibiting chain elongation and termination?
Which antibiotic preferentially binds to the 30S subunit of the microbial ribosome, interfering with binding of amino acyl-tRNA and inhibiting chain elongation and termination?
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What is the mechanism of action of tigecycline?
What is the mechanism of action of tigecycline?
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Which antibiotic causes deposition in bones and teeth, leading to potential damage in developing teeth and bones?
Which antibiotic causes deposition in bones and teeth, leading to potential damage in developing teeth and bones?
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What distinguishes Amikacin from other aminoglycosides in terms of resistance?
What distinguishes Amikacin from other aminoglycosides in terms of resistance?
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What is the serious side effect associated with chloramphenicol?
What is the serious side effect associated with chloramphenicol?
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What is the main route of excretion for tetracyclines?
What is the main route of excretion for tetracyclines?
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What is the primary reason tetracyclines limit absorption and cause damage to bones and teeth?
What is the primary reason tetracyclines limit absorption and cause damage to bones and teeth?
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Which enzyme is critical for chromosomal segregation in some bacterial strains?
Which enzyme is critical for chromosomal segregation in some bacterial strains?
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What is the main mechanism of action of fluoroquinolones (Quinolones)?
What is the main mechanism of action of fluoroquinolones (Quinolones)?
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What effect does dietary calcium have on the absorption of Ciprofloxacin?
What effect does dietary calcium have on the absorption of Ciprofloxacin?
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Which type of bacteria are usually less susceptible to fluoroquinolones?
Which type of bacteria are usually less susceptible to fluoroquinolones?
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What is the clinical use of fluoroquinolones?
What is the clinical use of fluoroquinolones?
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What is the spectrum of fluoroquinolones?
What is the spectrum of fluoroquinolones?
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What does DNA gyrase do in bacteria?
What does DNA gyrase do in bacteria?
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"Gyrase Inhibitors e.g. Fluoroquinolones (Quinolones)" are primarily bacteriostatic or bacteriocidal?
"Gyrase Inhibitors e.g. Fluoroquinolones (Quinolones)" are primarily bacteriostatic or bacteriocidal?
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"Fluoroquinolones generally have good absorption and distribution, with the highest concentrations accumulating in:
"Fluoroquinolones generally have good absorption and distribution, with the highest concentrations accumulating in:
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Which enzyme is responsible for the cross-linking of peptidoglycan molecules in the bacterial cell wall?
Which enzyme is responsible for the cross-linking of peptidoglycan molecules in the bacterial cell wall?
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Why are penicillins bactericidal when bacteria are in their growth and replication phase?
Why are penicillins bactericidal when bacteria are in their growth and replication phase?
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What is the main mechanism of development of hypersensitivity against penicillins?
What is the main mechanism of development of hypersensitivity against penicillins?
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Why can high doses of penicillins lead to neurotoxicity?
Why can high doses of penicillins lead to neurotoxicity?
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Which enzyme do many bacteria produce to open the β-lactam ring and destroy the activity of penicillin antibiotics?
Which enzyme do many bacteria produce to open the β-lactam ring and destroy the activity of penicillin antibiotics?
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What is the irreversible inhibitor of many bacterial β-lactamases?
What is the irreversible inhibitor of many bacterial β-lactamases?
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What is the primary target of β-lactam antibiotics within bacterial cells?
What is the primary target of β-lactam antibiotics within bacterial cells?
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Why are β-lactam antibiotics able to selectively target bacteria?
Why are β-lactam antibiotics able to selectively target bacteria?
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Which enzyme is critical for chromosomal segregation in some bacterial strains?
Which enzyme is critical for chromosomal segregation in some bacterial strains?
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What is the mechanism of action of tigecycline?
What is the mechanism of action of tigecycline?
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Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
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Which macrolide antibiotic has the most unusual property of uptake into several tissues, maintaining high concentrations for prolonged periods?
Which macrolide antibiotic has the most unusual property of uptake into several tissues, maintaining high concentrations for prolonged periods?
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What is the primary mechanism of action of tetracyclines?
What is the primary mechanism of action of tetracyclines?
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Which antibiotic is associated with a black box warning for acute pancreatitis and should only be used as a last resort?
Which antibiotic is associated with a black box warning for acute pancreatitis and should only be used as a last resort?
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Which antibiotic has the potential to cause irreversible aplastic anemia, reversible bone marrow depression, and 'gray baby' syndrome in neonates?
Which antibiotic has the potential to cause irreversible aplastic anemia, reversible bone marrow depression, and 'gray baby' syndrome in neonates?
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Which enzyme do aminoglycosides inhibit in bacteria?
Which enzyme do aminoglycosides inhibit in bacteria?
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Which antibiotic has good penetration into cerebrospinal fluid, ocular fluids, and joint fluids due to its high lipid solubility?
Which antibiotic has good penetration into cerebrospinal fluid, ocular fluids, and joint fluids due to its high lipid solubility?
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Which class of antibiotics bind to the P site of the 50S bacterial ribosomal subunit and block protein synthesis when a large amino acid or a polypeptide is in the P site?
Which class of antibiotics bind to the P site of the 50S bacterial ribosomal subunit and block protein synthesis when a large amino acid or a polypeptide is in the P site?
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Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
Which antibiotic binds to the σ subunit of RNA polymerase, leading to RNA polymerase entering a 'closed clamp' conformation and inhibiting transcription and translation?
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What is the mechanism of action of chloramphenicol?
What is the mechanism of action of chloramphenicol?
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What makes azithromycin unusual compared to other macrolide antibiotics?
What makes azithromycin unusual compared to other macrolide antibiotics?
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Which antibiotic has minimal absorption and remains mainly in the gastrointestinal tract, making its main clinical use in C. difficile infections?
Which antibiotic has minimal absorption and remains mainly in the gastrointestinal tract, making its main clinical use in C. difficile infections?
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What is the primary target of tetracyclines within bacterial cells?
What is the primary target of tetracyclines within bacterial cells?
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Which antibiotic is chemically similar but pharmacologically different to erythromycin, and binds to the σ subunit of RNA polymerase?
Which antibiotic is chemically similar but pharmacologically different to erythromycin, and binds to the σ subunit of RNA polymerase?
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What is the mechanism of action of vancomycin?
What is the mechanism of action of vancomycin?
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Which antibiotic is specifically effective against Pseudomonas aeruginosa?
Which antibiotic is specifically effective against Pseudomonas aeruginosa?
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What is the primary mechanism of action of daptomycin?
What is the primary mechanism of action of daptomycin?
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What is the main spectrum of activity for aztreonam?
What is the main spectrum of activity for aztreonam?
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Which antibiotic has the broadest spectrum of all β-lactam antibiotics?
Which antibiotic has the broadest spectrum of all β-lactam antibiotics?
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What is the specific inhibitor that prolongs the half-life of imipenem and limits its renal toxicity?
What is the specific inhibitor that prolongs the half-life of imipenem and limits its renal toxicity?
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What is the primary mechanism of action of gyrase inhibitors like fluoroquinolones?
What is the primary mechanism of action of gyrase inhibitors like fluoroquinolones?
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Which enzyme is critical for chromosomal segregation in some bacterial strains?
Which enzyme is critical for chromosomal segregation in some bacterial strains?
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Why are fluoroquinolones like ciprofloxacin generally not effective against gram-positive bacteria?
Why are fluoroquinolones like ciprofloxacin generally not effective against gram-positive bacteria?
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What is the effect of dietary calcium on the absorption of ciprofloxacin?
What is the effect of dietary calcium on the absorption of ciprofloxacin?
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What is the primary clinical use of fluoroquinolones like ciprofloxacin?
What is the primary clinical use of fluoroquinolones like ciprofloxacin?
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What is the main characteristic of fluoroquinolones that allows for selective toxicity to bacteria over eukaryotic cells?
What is the main characteristic of fluoroquinolones that allows for selective toxicity to bacteria over eukaryotic cells?
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What is the most common adverse effect associated with fluoroquinolones like ciprofloxacin?
What is the most common adverse effect associated with fluoroquinolones like ciprofloxacin?
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Which type of bacteria are usually less susceptible to fluoroquinolones?
Which type of bacteria are usually less susceptible to fluoroquinolones?
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What effect does high dietary calcium have on the excretion of ciprofloxacin?
What effect does high dietary calcium have on the excretion of ciprofloxacin?
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Which bacterial enzyme can introduce negative supercoils into bacterial DNA?
Which bacterial enzyme can introduce negative supercoils into bacterial DNA?
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Study Notes
Bacterial Cell Wall
- The enzyme responsible for cross-linking peptidoglycan molecules in the bacterial cell wall is transpeptidase.
Penicillins
- Penicillins are bactericidal during the growth and replication phase.
- Penicillinase-resistant penicillins are effective against gram-positive organisms and remain useful if the bacteria produce penicillinase.
- Clavulanate is an irreversible inhibitor of many bacterial β-lactamases.
- High doses of penicillins can lead to neurotoxicity.
- The most common adverse effect of penicillins is hypersensitivity.
- β-lactamases are produced by many bacteria to open the β-lactam ring and destroy the activity of penicillin antibiotics.
β-lactam Antibiotics
- Transpeptidase is the primary target of β-lactam antibiotics within bacterial cells.
- β-lactam antibiotics are able to selectively target bacteria because they inhibit cell wall synthesis.
- The key factor contributing to the high selectivity of β-lactam antibiotics for bacteria over human cells is the presence of peptidoglycan in bacterial cell walls.
Macrolide Antibiotics
- Azithromycin is a macrolide antibiotic with unusual properties, including uptake into several tissues, maintaining high concentrations for prolonged periods.
- Erythromycin is a macrolide antibiotic that binds to the P site of the 50S bacterial ribosomal subunit and blocks protein synthesis.
Other Antibiotics
- Tigecycline binds to the 30S subunit of the microbial ribosome, interfering with binding of amino acyl-tRNA and inhibiting chain elongation and termination.
- Tetracyclines bind to the 30S subunit of the microbial ribosome, interfering with binding of amino acyl-tRNA and inhibiting chain elongation and termination.
- Fluoroquinolones are gyrase inhibitors that inhibit DNA replication and transcription.
- Aminoglycosides inhibit protein synthesis by binding to the 30S subunit of the bacterial ribosome.
- Chloramphenicol binds to the 50S subunit of the bacterial ribosome, inhibiting protein synthesis.
- Vancomycin inhibits cell wall synthesis by binding to the terminal D-alanyl-D-alanine residue of peptidoglycan.
- Daptomycin inhibits bacterial cell membrane function.
- Aztreonam has a narrow spectrum of activity against gram-negative bacteria.
- Imipenem is a broad-spectrum β-lactam antibiotic.
- Cilastatin is a specific inhibitor that prolongs the half-life of imipenem and limits its renal toxicity.
Fluoroquinolones
- Gyrase is the bacterial enzyme that introduces negative supercoils into bacterial DNA.
- Fluoroquinolones are generally not effective against gram-positive bacteria.
- Dietary calcium decreases the absorption of ciprofloxacin.
- The primary clinical use of ciprofloxacin is against gram-negative bacteria.
- The main characteristic of fluoroquinolones that allows for selective toxicity to bacteria over eukaryotic cells is inhibition of DNA replication and transcription.
- The most common adverse effect associated with fluoroquinolones is gastrointestinal disturbance.
- Gram-positive bacteria are usually less susceptible to fluoroquinolones.
- High dietary calcium has no effect on the excretion of ciprofloxacin.
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Description
Test your knowledge on the mechanism of action of macrolide antibiotics, with a focus on erythromycin. Learn about the binding to the P site of the bacterial ribosomal subunit and its effect on protein synthesis. Explore the spectrum and properties of macrolide antibiotics.
