Deck 20: Antibiotic Resistance

Question 1

Resistance to _____ requires five separate genes to alter peptidoglycan to an insensitive form.

A)Methicillin
B)Tetracycline
C)Erythromycin
D)Vancomycin
E)Penicillin

Answer 1

Vancomycin

Question 2

Which of the following statements is false?

A)The more an antibiotic is prescribed, the more rapidly resistance to that antibiotic develops
B)Antibiotic-resistant strains of bacteria are likely to develop in the hospital
C)Antibiotics are ineffective against viral infections and do not alleviate symptoms
D)The superinfection effect is a consequence of using narrow-spectrum antibiotics
E)Misuse of antibiotics can perturb the balance of normal flora in the body

Answer 2

The superinfection effect is a consequence of using narrow-spectrum antibiotics

Question 3

Which of the following is not a mechanism for acquiring resistance to antibiotics?

A)Alteration of a metabolic pathway
B)Modification of the component targeted by the antibiotic
C)Inactivation of the antibiotic by enzymatic breakdown
D)Using an efflux pump to transport antibiotics out of the cell once they have entered
E)Increasing the growth rate to decrease inhibitory concentrations

Answer 3

Increasing the growth rate to decrease inhibitory concentrations

Question 4

Resistance to Methicillin developed rapidly because

A)It was overprescribed
B)It was used inappropriately
C)Bacteria can synthesize this compound
D)It was never used in hospital settings
E)It was not destroyed by ?-lactamase

Question 5

By incorporating antibiotics into animal feed,farmers

A)Increase the weight gains of their livestock and can create antibiotic resistant microbes
B)Extend the period cattle spend in feedlots
C)Prevent viral diseases in their herds
D)Reduce the incidence of foot-and-mouth disease in their livestock

Question 6

Which of the following accounts for more than 90% of all vancomycin-resistant bacteria?

A)Pseudomonas aeruginosa
B)Staphylococcus aureus
C)Escherichia coli
D)Clostridium difficile
E)Enterococcus faecalis

Question 7

Which of the following statements is true?

A)Antibiotic resistance genes account for 20 percent of the total S. aureus genome
B)The chromosome of MRSA contains 3-4 resistance islands
C)The mecA gene confers resistance to vancomycin
D)Mobile genetic elements in MRSA carry fewer than 15 resistance-conferring gene clusters

Question 8

With reference to antibiotic resistance in MRSA,which of the following is a mismatched pair?

A)β-lactam antibiotic resistance: mecA gene
B)Mobile genetic elements: more than 20 resistance-conferring gene clusters
C)Tetracycline resistance: efflux pumps
D)Alteration of ribosomes: erythromycin resistance
E)Antibiotic resistance genes: 7% of genome

Question 9

The process used to generate thousands of drugs daily with the aid of computer programs is referred to as

A)High-throughput screening
B)Bioinformatics
C)Combinatorial chemistry
D)Genome sequencing
E)Mechanism-based screening

Question 10

Which of the following is not used for susceptibility testing of antibiotics?

A)Kirby-Bauer method
B)Phenol coefficient
C)E test
D)Disk diffusion method

Question 11

Which of the following is not an example of an auto-protective mechanism used by microbes producing antibiotics?

A)Using a transmembrane pump to export newly synthesized antibiotics
B)Co-expressing genes for membrane-bound protein export pumps and antibiotic production
C)Altering the structure of the 50S ribosomal subunit
D)Producing antibody only during the log phase of growth
E)Synthesizing a precursor form of the antibiotic that is activated only after it has been exported by the microbe

Question 12

Which of the following is not a characteristic of an efflux pump?

A)They are encoded by genes carried on plasmids
B)Some are energy-independent
C)They are embedded in the plasma membrane of Gram-positive cells
D)Some operate using a counter-exchange of antibiotic for cations
E)The genes encoding efflux pumps can be transferred to other bacteria

Question 13

The minimal inhibitory concentration (MIC)is determined using the

A)Kirby-Bauer method
B)E test
C)Disk diffusion method
D)Broth dilution test

Question 14

Which of the following antibiotics is MRSA not resistant to?

A)Aminoglucosides
B)Methicillin
C)Tetracyclines
D)Vancomycin
E)Erythromycin

Question 15

Which of the following is a superinfection pathogen of the gastrointestinal tract associated with the overuse of broad-spectrum antibiotics?

A)Escherichia coli
B)Pseudomonas aeruginosa
C)Clostridium difficile
D)Bacillus subtilis
E)Staphylococcus aureus

Question 16

Which of the following statements is false?

A)Escherichia coli O157:H7 decreases the production of porin to decrease membrane permeability and thus block antibiotic uptake
B)The expression of the Tet A gene is regulated
C)Pseudomonas increases the production of porin to facilitate the exportation of antibiotics
D)Antibiotic target modification to escape antibiotic activity is successful only if the target retains its ability to function
E)Methicillin-resistant Staphylococcus aureus (MRSA) organisms have imported the mecA gene, which encodes a modified penicillin-binding protein (PBP) that is insensitive to penicillin antibiotics

Question 17

Which of the following is not a contributory factor to the development of drug resistance?

A)Non-compliance with prescribed drug regimen
B)Underprescription of drugs needed to treat infections
C)Overprescription of broad-spectrum antibiotics
D)Lack of stringency when following aseptic practices in health care facilities
E)Incorporating antibiotics into animal feed

Question 18

Antibiotic resistance by drug inactivation is when

A)Specialized proteins are activated
B)One metabolic pathway is blocked and another is used
C)Porins and membrane channel proteins are not produced
D)An enzyme cleaves a portion of the antibiotic

Question 19

Locations in the bacterial genome where antibiotic resistance genes integrate and accumulate are known as

A)Integrons
B)Resistance islands
C)Superinfection sites
D)Opportunistic sites

Question 20

Which of the following is a mismatched pair in reference to antibiotic compounds composed of peptide fragments and where they are derived from?

A)Drosocin: insects
B)Nisin: Gram-positive bacteria
C)Apidaecin: insects
D)Defensins: Gram-negative bacteria
E)lantibiotics: Gram-positive bacteria

Question 21

Explain why ?-lactamase is expressed only after the cell wall has begun its degradation by penicillin in Escherichia coli.

Question 22

Which type of antibiotic resistance occurs when the shape of the ribosome is changed?

A)Drug inactivation
B)Target modification
C)Efflux pumping
D)Alternate pathway

Question 23

Answer true or false to the reason given in the following statement: The hospital is a place where resistance can develop rapidly because there is a high concentration of bacteria and small amounts of antibiotics are constantly used.

Question 24

Answer true or false to the reason given in the following statement: Because antibiotics are not effective against viruses,taking the antibiotic a doctor prescribes for a viral infection does nothing to relieve symptoms.

Question 25

Describe the test used to determine whether an antimicrobial agent is microbicidal.

Question 26

Compare and contrast the Kirby-Bauer test and the E test.Why are these not appropriate procedures for determining whether an antimicrobial agent is microbicidal?

Question 27

Identify and describe five factors that contribute to the growing problem of antibiotic resistance in today's world.

Question 28

Explain the testing process through which potential new antibiotics must pass before therapeutic use in humans is considered.

Question 29

Why is selective toxicity particularly problematic when developing antimicrobials to treat viral infections?

Question 30

Describe the four types of protective mechanism microbes use to develop resistance to antibiotics.Provide an example of each type.

Question 31

Describe six approaches being used to identify novel microbial structures or functions that may be potential new antibiotic targets.

Question 32

Answer true or false to the reason given in the following statement: In large cities the transfer of a contagious disease or antibiotic-resistant pathogen is more easily accomplished because the population is more spread out.

Question 33

Specialized membrane proteins are activated in which type of antibiotic resistance?

A)Drug inactivation
B)Target modification
C)Efflux pumping
D)Alternate pathway

Question 34

Identify six important ways in which the life span of antimicrobial drugs can be extended for health care use.

Question 35

Which type of resistance occurs when one metabolic pathway is blocked and others are used?

A)Drug inactivation
B)Target modification
C)Efflux pumping
D)Alternate pathway

Question 36

Antibiotic resistance by reduced membrane permeability occurs when

A)Specialized proteins are activated
B)One metabolic pathway is blocked and another is used
C)Porins and membrane channel proteins are not produced
D)An enzyme cleaves a portion of the antibiotic

Question 37

Answer true or false to the reason given in the following statement: Bacterial efflux pumps can generate antibiotic resistance because they can function to clear bacteria of antibiotics.