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Questions and Answers
What does MIC stand for in microbiology?
What does MIC stand for in microbiology?
- Microbial Inhibition Control
- Maximum Inhibitory Concentration
- Minimum Inhibitory Capacity
- Minimum Inhibitory Concentration (correct)
How is MBC different from MIC?
How is MBC different from MIC?
- MBC tests the effect of increasing concentrations of antibiotic, while MIC tests decreasing concentrations.
- MBC indicates the highest concentration of the antibacterial agent, while MIC indicates the lowest.
- MBC shows the level of agent that inhibits growth, while MIC shows the one that kills bacteria.
- MBC is the lowest level of antimicrobial agent resulting in microbial death, MIC is the lowest level of antimicrobial agent that greatly inhibits growth. (correct)
Why might a bacterium survive even if the MIC test shows inhibition?
Why might a bacterium survive even if the MIC test shows inhibition?
- The bacterium was already dead before the test.
- Because the bacterium has an inherent resistance to antimicrobials.
- Due to the absence of antimicrobial agents in the environment.
- The bacterium was only momentarily inhibited by the agent. (correct)
When are antibacterial agents considered bactericidal according to the text?
When are antibacterial agents considered bactericidal according to the text?
Which statement best explains the purpose of measuring MBC in microbiology?
Which statement best explains the purpose of measuring MBC in microbiology?
Which antibiotic group also acts on the cell membrane like Vancomycin?
Which antibiotic group also acts on the cell membrane like Vancomycin?
Leading cause of nosocomial (hospital related) infections and are known to be resistant to antimicrobial products, except
Leading cause of nosocomial (hospital related) infections and are known to be resistant to antimicrobial products, except
What contributes to resistance to Vancomycin in bacteria?
What contributes to resistance to Vancomycin in bacteria?
What is the primary action of Vancomycin in inhibiting bacterial growth?
What is the primary action of Vancomycin in inhibiting bacterial growth?
Which type of bacteria is primarily targeted by Vancomycin?
Which type of bacteria is primarily targeted by Vancomycin?
What is the usual bactericidal concentration range of Vancomycin?
What is the usual bactericidal concentration range of Vancomycin?
Which bacterium is associated with the production of Cycloserine?
Which bacterium is associated with the production of Cycloserine?
What is a major side effect associated with Cycloserine use?
What is a major side effect associated with Cycloserine use?
Which bacterial infections is Cycloserine commonly used to treat?
Which bacterial infections is Cycloserine commonly used to treat?
Why should Cycloserine not be applied to wounds for the purpose of preventing infection?
Why should Cycloserine not be applied to wounds for the purpose of preventing infection?
Which enzyme does Cycloserine inhibit in bacterial cells?
Which enzyme does Cycloserine inhibit in bacterial cells?
Which type of bacteria does Cycloserine inhibit?
Which type of bacteria does Cycloserine inhibit?
How is Cycloserine excreted from the body?
How is Cycloserine excreted from the body?
Which type of infection is commonly treated with parenteral Vancomycin in combination with Cefotaxime, Ceftriaxone, or Rifampin?
Which type of infection is commonly treated with parenteral Vancomycin in combination with Cefotaxime, Ceftriaxone, or Rifampin?
How is Vancomycin primarily administered due to its poor absorption from the intestinal tract?
How is Vancomycin primarily administered due to its poor absorption from the intestinal tract?
Important indications for parenteral Vancomycin are bloodstream infections and endocarditis caused by:
Important indications for parenteral Vancomycin are bloodstream infections and endocarditis caused by:
Why is Bacitracin not used systemically and is only applied topically?
Why is Bacitracin not used systemically and is only applied topically?
What is the mechanism of action of Bacitracin against microorganisms?
What is the mechanism of action of Bacitracin against microorganisms?
Why is Bacitracin only used topically and not systemically?
Why is Bacitracin only used topically and not systemically?
What is the primary concern when using Bacitracin systemically?
What is the primary concern when using Bacitracin systemically?
Flashcards
What is MIC?
What is MIC?
The lowest concentration of an antibacterial agent that inhibits bacterial growth.
What is MBC?
What is MBC?
The lowest concentration of an antibacterial agent that kills 99.9% of bacteria.
What are bactericidal agents?
What are bactericidal agents?
Antibacterial agents that can kill 99.9% of bacteria at a specific concentration.
Why is MBC important?
Why is MBC important?
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What is Vancomycin?
What is Vancomycin?
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What is Vancomycin used for?
What is Vancomycin used for?
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What is the typical bactericidal concentration of Vancomycin?
What is the typical bactericidal concentration of Vancomycin?
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How can resistance to Vancomycin occur?
How can resistance to Vancomycin occur?
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What is Cycloserine?
What is Cycloserine?
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What is a major side effect of Cycloserine?
What is a major side effect of Cycloserine?
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What is Cycloserine used to treat?
What is Cycloserine used to treat?
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Why shouldn't Cycloserine be applied to wounds?
Why shouldn't Cycloserine be applied to wounds?
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What is the mechanism of action of Cycloserine?
What is the mechanism of action of Cycloserine?
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How is Cycloserine eliminated from the body?
How is Cycloserine eliminated from the body?
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What is vancomycin used in combination with?
What is vancomycin used in combination with?
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How is vancomycin administered?
How is vancomycin administered?
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When is parenteral Vancomycin used?
When is parenteral Vancomycin used?
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What is Bacitracin?
What is Bacitracin?
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What is the mechanism of action of Bacitracin?
What is the mechanism of action of Bacitracin?
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Why is Bacitracin only used topically?
Why is Bacitracin only used topically?
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Study Notes
MIC and MBC
- MIC stands for Minimum Inhibitory Concentration, the lowest concentration of an antibacterial agent that inhibits bacterial growth.
- MBC (Minimum Bactericidal Concentration) is different from MIC in that it is the lowest concentration of an antibacterial agent that kills 99.9% of bacteria.
- A bacterium may survive even if the MIC test shows inhibition if the bacterium is not killed by the antibacterial agent, but only inhibited.
Antibacterial Agents
- Antibacterial agents are considered bactericidal if they can kill 99.9% of bacteria at a specific concentration.
- Measuring MBC is important to determine the concentration of an antibacterial agent needed to kill bacteria, rather than just inhibit growth.
- Vancomycin is a bactericidal antibiotic that acts on the cell membrane, similar to Polymyxins.
Vancomycin
- Vancomycin is primarily used to target Gram-positive bacteria, particularly Staphylococcus aureus and Streptococcus pneumoniae.
- The primary action of Vancomycin is to inhibit bacterial cell wall synthesis by binding to the D-Ala-D-Ala terminus of peptidoglycan.
- The usual bactericidal concentration range of Vancomycin is 1-4 μg/mL.
- Resistance to Vancomycin in bacteria can occur due to the alteration of the D-Ala-D-Ala terminus of peptidoglycan.
Cycloserine
- Cycloserine is an antibiotic produced by Streptomyces orchidaceus.
- A major side effect of Cycloserine use is neurological toxicity, including seizures and psychosis.
- Cycloserine is commonly used to treat tuberculosis and other infections caused by Mycobacterium tuberculosis.
- Cycloserine should not be applied to wounds to prevent infection because it can cause neurological toxicity and is not effective against most bacteria.
- Cycloserine inhibits the enzyme D-alanine:D-alanine ligase in bacterial cells, which is necessary for peptidoglycan synthesis.
- Cycloserine is primarily excreted from the body through the kidneys.
Clinical Applications
- Vancomycin is often administered in combination with Cefotaxime, Ceftriaxone, or Rifampin to treat meningitis and other infections.
- Vancomycin is primarily administered intravenously due to its poor absorption from the intestinal tract.
- Parenteral Vancomycin is indicated for bloodstream infections and endocarditis caused by methicillin-resistant Staphylococcus aureus (MRSA) and other Gram-positive bacteria.
Bacitracin
- Bacitracin is not used systemically due to its nephrotoxicity and is only applied topically.
- The mechanism of action of Bacitracin is to inhibit the dephosphorylation of C55-polyisoprenyl diphosphate, which is necessary for peptidoglycan synthesis.
- Bacitracin is only used topically because of its nephrotoxicity, which can cause kidney damage when used systemically.
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Description
Test your knowledge on Minimum Inhibitory Concentration (MIC) which is the lowest concentration of an antimicrobial agent that prevents the visible growth of bacteria. Evaluate the antimicrobial efficacy of various compounds by measuring the effect of decreasing concentrations of antibiotics/antiseptics over a defined period in terms of inhibition of microbial population growth.
