MICR 4423 EXAM 5 QUESTIONS AND
CORRECT ANSWERS!!
How do we define antibiotic resistance?
Continued growth of bacterial cells in the presence of an antibiotic that would normally stop
growth or kill the cells
What are the 4 main ways that bacterial cells can achieve antibiotic resistance? Give an
example of a mechanism for each way.
- Block import
-- alteration of the porins in the outer membrane of gram negative cells so that they are more
restrictive
- Efflux
-- efflux pumps
- Modify or destroy the antibiotic
-- beta-lactamases
- Target modification
-- point mutations
What is innate resistance to antibiotics?
Resistance of antibiotic producers
What is one way that an antibiotic producer can protect itself from the antibiotics it
makes?
- Make an efflux pump or protective protein at the same time as the antibiotic
- Complete the last step of biosynthesis outside the cell
What is acquired resistance to antibiotics?
Resistance of non-antibiotic producers
, How can acquired resistance be acquired by cells?
- spontaneous mutations
- horizontal gene transfer
What are some common means by which antibiotic resistance genes can be acquired by
cells?
- ucompetence
- bacterial conjugation
- phase transduction
What is the difference between genetic and non-genetic resistance?
Genetic: semi-permanent
non-Genetic: temporary
What are two examples of non-genetic antibiotic resistance?
- persistence
- biofilm formation
- tolerance
How does resistance compare to tolerance and persistence?
Resistance is typically genetic and allows cells to grow and thrive in the presence of antibiotics.
Tolerance and persistence allow cells to survive transient exposure.
Tolerance usually applies to the entire population and is mediated by environmental effects or
genetic effects, and causes cells to grow more slowly as a population.
Persistence is a small sub-population of cells that is not growing so it can survive antibiotics
What is meant by the resistome?
All the resistance genes/mechanisms that are out there
What are the ESKAPE pathogens and why are they important?
CORRECT ANSWERS!!
How do we define antibiotic resistance?
Continued growth of bacterial cells in the presence of an antibiotic that would normally stop
growth or kill the cells
What are the 4 main ways that bacterial cells can achieve antibiotic resistance? Give an
example of a mechanism for each way.
- Block import
-- alteration of the porins in the outer membrane of gram negative cells so that they are more
restrictive
- Efflux
-- efflux pumps
- Modify or destroy the antibiotic
-- beta-lactamases
- Target modification
-- point mutations
What is innate resistance to antibiotics?
Resistance of antibiotic producers
What is one way that an antibiotic producer can protect itself from the antibiotics it
makes?
- Make an efflux pump or protective protein at the same time as the antibiotic
- Complete the last step of biosynthesis outside the cell
What is acquired resistance to antibiotics?
Resistance of non-antibiotic producers
, How can acquired resistance be acquired by cells?
- spontaneous mutations
- horizontal gene transfer
What are some common means by which antibiotic resistance genes can be acquired by
cells?
- ucompetence
- bacterial conjugation
- phase transduction
What is the difference between genetic and non-genetic resistance?
Genetic: semi-permanent
non-Genetic: temporary
What are two examples of non-genetic antibiotic resistance?
- persistence
- biofilm formation
- tolerance
How does resistance compare to tolerance and persistence?
Resistance is typically genetic and allows cells to grow and thrive in the presence of antibiotics.
Tolerance and persistence allow cells to survive transient exposure.
Tolerance usually applies to the entire population and is mediated by environmental effects or
genetic effects, and causes cells to grow more slowly as a population.
Persistence is a small sub-population of cells that is not growing so it can survive antibiotics
What is meant by the resistome?
All the resistance genes/mechanisms that are out there
What are the ESKAPE pathogens and why are they important?
