Antimicrobial Drugs - Chapter Exam 15

Misuse of antibiotics can lead to _____. antibiotic resistance bacterial debilitation bacterial activation antibiotic inactivation

antibiotic resistance

What is a zone of inhibition? A. An area of the body where bacteria don't grow B. An area of the body where an antibiotic can kill bacteria C. An area on an agar plate where bacteria don't grow because of an antibiotic D. An area on an agar plate where antibiotics are inhibited E. An area of the body where bacteria are present in high numbers

C. An area on an agar plate where bacteria don't grow because of an antibiotic

Which kind of antibiotic must reach very high concentrations to be effective? A. Antagonistic B. MIC C. Concentration-dependent D. Time-dependent E. Highly concentrated

C. Concentration-dependent

Which is resistant to more drugs: MRSA or VRSA? A. they are both resistant to the same exact drugs B. MRSA C. VRSA D. neither are drug-resistant E. they are both resistant to the same number of drugs, but different ones

C. VRSA

What is the difference between MRSA and VRSA? MRSA and VRSA are both resistant to the same exact drugs, but MRSA is more contagious. VRSA affects people with HIV more, and MRSA affects people with TB more. VRSA is a type of bacteria that is not only resistant to penicillin-type drugs (MRSA) but also vancomycin. MRSA is a type of bacteria that is not only resistant to penicillin-type drugs (VRSA) but also methicillin. MRSA is worse than VRSA because there is no antibiotic that will kill these bacteria.

VRSA is a type of bacteria that is not only resistant to penicillin-type drugs (MRSA) but also vancomycin.

Which of these statements is FALSE? Ethambutol is a drug that specifically inhibits the synthesis of mycobacterial cell walls. Isoniazid is a relatively weak drug that can only be given in combination with stronger drugs. Anti-mycobacterial drugs must be able to penetrate cells and tissues well. Mycobacteria cause tuberculosis and leprosy.

Isoniazid is a relatively weak drug that can only be given in combination with stronger drugs.

Why is trimethoprim selectively toxic? Its target enzyme is found in both humans and bacteria, but the drug binds much more effectively to the human enzyme. It inhibits an enzyme that is only present in bacteria. It inhibits an enzyme that is only present in the enzyme found in the human enzyme. Its target enzyme is found in both humans and bacteria, but the drug binds much more effectively to the bacterial enzyme.

Its target enzyme is found in both humans and bacteria, but the drug binds much more effectively to the bacterial enzyme.

Jennifer has a cut in her leg, which has become infected by Staphylococcus bacteria. Which type of antibiotic would definitely work against the Staphylococcus bacteria? We cannot know for sure without testing the specific bacteria. A broad-spectrum penicillin. Penicillin. Penicillin, plus a beta-lactamase inhibitor.

We cannot know for sure without testing the specific bacteria.

Which of the following antibiotics inhibit cell wall synthesis? Rifamycins Bacitracin Quinolones Polymyxin B

Bacitracin

Antibiotics that poke holes in the plasma membranes of bacteria are: Bacteriostatic Broad-spectrum Narrow-spectrum Cell wall synthesis inhibitors Bactericidal

Bactericidal

Which type of antibiotics stop bacteria from growing without killing them? Bacteriostatic Narrow Spectrum Bactericidal Broad Spectrum

Bacteriostatic

Which of the following is why a doctor would NOT test a microbe's antibiotic susceptibility? Because antibiotic resistance is prevalent nowadays To determine the appropriate dose Because the microbe is unknown Because doctors never know which antibiotic to start with

Because doctors never know which antibiotic to start with

How do bacteria become resistant to antibiotics? By a genetic mutation By transforming into a virus By individuals misusing antibiotics By requiring resistance from another bacterium or by a genetic mutation

By requiring resistance from another bacterium or by a genetic mutation

Which of the following is an example of an acute viral infection? Flu All the answers are correct Hepatitis Papilloma

Flu

Which of the following antibiotics damages the plasma membrane of bacteria? Bacitracin Quinolones Rifamycins Polymyxin B

Polymyxin B

Which of the following statements about rifamycins is FALSE? Rifamycins are selectively toxic. Rifamycins are broad-spectrum antibiotics. Rifamycins inhibit bacterial transcription. Rifamycins cannot penetrate well into body tissues.

Rifamycins cannot penetrate well into body tissues.

Which of the following viruses is NOT typically treated with antiviral drugs? Herpes Influenza Hepatitis C Sinus infection

Sinus infection

Which of these antibiotics prevents tRNAs from attaching to the A site of the ribosome? A Streptogramin An Oxazolidinone Tetracycline Chloramphenicol

Tetracycline

What is a helminth? it means parasite a parasitic worm a single-celled protozoan a virus an amoeba

a parasitic worm

Which of these molecules is present in fungal cell membranes but not in animal cell membranes? cholesterol ergosterol flucytosine beta-glucan fluconazole

ergosterol

Antimicrobial peptides tend to be _____ charged, and bacterial surfaces tend to be _____ charged. positively; negatively neutral; negatively neutral; positively negatively; positively

positively; negatively

A patient arrives in a hospital with worms. A doctor wants to prescribe a drug that will make the worms more susceptible to the actions of the patient's own immune system. Which drug should the doctor prescribe? chloroquine mebendazole niclosamide praziquantel

niclosamide

Which of these drugs does NOT interfere with parasites' DNA? A. all of these drugs inhibit parasites' DNA in some way B. metronidazole C. niclosamide D. chloroquine E. artemisinin-based combination therapies

niclosamide

A patient comes to a clinic and complains of severe gastrointestinal problems. They tell the doctor that they had been swimming in a public pool recently and got water up their nose several times, which they also swallowed. Which drug might be a good choice for this patient? chloroquine nitazoxanide praziquantel artemisinin-based combination therapies

nitazoxanide

DNA gyrase is inhibited from resealing strands by _____. polymyxin B bacitracin rifamycins quinolones

rifamycins

How could a doctor BEST justify using an antibiotic, such as tetracycline, for a patient who arrives at the emergency room with a severely infected wound and symptoms indicating that the bacteria has entered the patient's blood? A broad-specrum antibiotic, such as tetracyline, is the safest choice given the scenario. This is because blood infections will only respond to broad spectrum antibiotics. There is no justification. In the case of a severe infection, only narrow-spectrum antibiotics work. It is the safest choice given the scenario. Narrow-spectrum antibiotics, such as tetracycline, are the only types of antibiotics that work on blood infections. A broad-specturm antibiotic, such as tetracyline, is the safest choice given the scenario. In this case there is no time to culture the microbes to see which narrow-spectrum antibiotic will work. It is the safest choice given the scenario. Narrow-spectrum antibiotics, such as tetracylcine, not only protect the patient, but also the hospital staff.

A broad-specturm antibiotic, such as tetracyline, is the safest choice given the scenario. In this case there is no time to culture the microbes to see which narrow-spectrum antibiotic will work.

If a patient came to the hospital with tuberculosis, which of these antibiotics would you prescribe? Why? A rifamycin, because it is bactericidal. A rifamycin, because it penetrates well into cells and tissues. A quinolone or fluoroquinolone, because they are bactericidal. A quinolone or fluoroquinolone, because they penetrate well into cells and tissues.

A rifamycin, because it penetrates well into cells and tissues.

Bacteria become resistant to rifamycin antibiotics by: A. Acquiring mutations that change the structure of RNA polymerase B. Secreting enzymes that degrade rifamycins C. The bacteria cannot become resistant to rifamycins D. Using an alternative pathway for nucleic acid synthesis E. Acquiring mutations that change the structure of topoisomerase IV

A. Acquiring mutations that change the structure of RNA polymerase

Why is penicillin more effective against Gram-positive than Gram-negative bacteria? A. Because Gram-negative bacteria are protected against penicillin's effects by a protective outer membrane that prevents penicillin from accessing their peptidoglycan layer. B. Because Gram-positive bacteria are protected against penicillin's effects by a protective outer membrane that prevents penicillin from accessing their peptidoglycan layer. C. Because Gram-negative bacteria are protected against penicillin's effects by a protective outer membrane that prevents penicillin from accessing their nuclear membrane. D. Because Gram-positive bacteria are protected against penicillin's effects by a protective outer membrane that prevents penicillin from accessing their nuclear membrane.

A. Because Gram-negative bacteria are protected against penicillin's effects by a protective outer membrane that prevents penicillin from accessing their peptidoglycan layer.

What is one way that scientists believe antimicrobial peptides achieve selective toxicity? A. Through positive and negative charge interactions at the cell surface B. Animal cell plasma membranes have very different structure than bacterial plasma membranes C. Animal cells have cell walls to protect their plasma membranes D. Antimicrobial peptides are attached to antibodies that can specifically recognize bacterial surfaces E. Only bacterial cells have plasma membranes

A. Through positive and negative charge interactions at the cell surface

A patient who has returned to the United States after vacationing in Africa was feeling ill; after a thorough examination his doctor determined that the patient is suffering from malaria. Which of these drugs would the doctor prescribe to treat the condition? a) Praziquantel b) Chloroquine c) Ivermectin d) Artemisinin-based combination therapies A. b and d B. c and d C. b and c D. d only E. a and c F. c only G. a and d H. a only I. b only J. a and b

A. b and d

Because penicillin is more effective against Gram-positive bacteria, it is an example of a/an antibiotic. A. narrow-spectrum B. toxic C. broad-spectrum D. ineffective E. synthetic

A. narrow-spectrum

Antibiotics interfere with various cellular mechanisms in order to kill bacteria. Which of the following is one of those mechanism? DNA/RNA synthesis Cell wall synthesis Protein synthesis All the answers are correct

All the answers are correct

For a minor fungal skin infection, like athlete's foot, which of these drugs would NOT be a good choice? Griseofulvin, given systemically Miconazole, given locally Amphotericin B, given systemically Clotrimazole, given locally

Amphotericin B, given systemically

What does it mean if two drugs have 'synergistic' effects? A. They should not be used together because they inhibit each other. B. It's good to use them together because they are more effective in combination. C. It's good to use them together because one drug changes the other drug to make it more effective. D. Synergism has nothing to do with drugs. E. They should not be used together because they would have toxic effects.

B. It's good to use them together because they are more effective in combination.

What is neuraminidase? A. a drug used to treat influenza B. a cold enzyme C. an influenza enzyme that allows a virus to exit host cells D. a drug used to treat viruses E. an influenza enzyme that allows it to enter cells

C. an influenza enzyme that allows a virus to exit host cells

A patient comes into the hospital with a severe intestinal infection. She says she is a technician in a biology lab that works with the Gram-negative bacterium Shigella flexneri, which you know causes dysentery. At the moment, your hospital has run out of all antibiotics except protein synthesis inhibitors. Which of these drugs would NOT be a good choice to give your patient? A. any of these would be a good choice B. tetracycline C. an oxazolidinone D. streptomycin E. none of these would be a good choice

C. an oxazolidinone

How do bacteria evolve antibiotic resistance? A. in response to the immune system B. evolution of antibiotic resistance is a random process that is unrelated to antibiotic treatment C. in response to the selective pressure that antibiotic treatment puts on them D. by hiding from the immune system E. by breaking down antibiotic molecules

C. in response to the selective pressure that antibiotic treatment puts on them

Which of the following is NOT a class of antiretroviral drugs? Entry/fusion inhibitors Reverse transcriptase inhibitors Cell wall synthesis inhibitors Integrase inhibitors

Cell wall synthesis inhibitors

A patient who returned to the United States after vacationing in Africa was feeling ill. After a thorough examination his doctor determined that the patient is suffering from malaria. Which of the following would the doctor prescribe to treat the condition? Praziquantel and artemisinin-based combination therapies Chloroquine and artemisinin-based combination therapies Ivermectin and praziquantel Ivermectin and chloroquine

Chloroquine and artemisinin-based combination therapies

Which of the following is TRUE of integrase? A. Integrase incorporates HIV's RNA-based genetic material into the host cell genome B. Integrase inhibitors cut HIV DNA out of the host cell genome C. Integrase is the enzyme that copies HIV's DNA into new RNA copies D. Integrase incorporates HIV's DNA-based genetic material into the host cell genome E. Integrase inhibitors stop HIV protein chains from being cut apart into their mature forms

D. Integrase incorporates HIV's DNA-based genetic material into the host cell genome

DNA gyrase plays an important role in DNA replication. What happens when this enzyme is inhibited by quinolones or fluoroquinolones? A. The bacterial chromosome binds to other components of the cell. B. All the answers are correct. C. The bacterial chromosome becomes longer than it usually is. D. The bacterial chromosome breaks into small fragments.

D. The bacterial chromosome breaks into small fragments.

What did Paul Ehrlich mean by a 'magic bullet'? A. a chemical that would selectively kill animal cells but not microbes B. a chemical that would selectively stain microbes but not animal cells C. he was referring to penicillin D. a chemical that would selectively kill microbes but not animal cells E. a chemical that would kill all cell types

D. a chemical that would selectively kill microbes but not animal cells

Which of these statements is not true? A. Anti-mycobacterial drugs must be able to penetrate cells and tissues well. B. Ethambutol is a drug that specifically inhibits the synthesis of mycobacterial cell walls. C. Mycobacteria can only live inside host cells. D. Mycobacteria cause tuberculosis and leprosy. E. Isoniazid is a relatively weak drug that can only be given in combination with stronger drugs.

E. Isoniazid is a relatively weak drug that can only be given in combination with stronger drugs.

What is the difference between cephalosporins and penicillins? A. Penicillins are only effective against Gram-negative bacteria, but cephalosporins are effective against both Gram-positive and Gram-negative bacteria. B. Penicillins and cephalosporins have completely different structures. C. Penicillins are derived from molds, but cephalosporins are not. D. Penicillins have beta-lactam rings, but cephalosporins do not. E. Penicillins and cephalosporins have different ring structures.

E. Penicillins and cephalosporins have different ring structures.

Which of the following is NOT a good target for a selectively toxic antimicrobial drug? The plasma membrane. The cell wall. Histones. Protein synthesis.

Histones.

What class of antibiotic does penicillin belong to? Quinolones Mycobacteria-specific antibiotics Inhibitors of protein synthesis Inhibitors of cell wall synthesis Sulfa drugs

Inhibitors of cell wall synthesis

An antibiotic that only works on Gram-negative bacteria is an example of what class of antibiotic? Broad-spectrum Bactericidal Cell wall inhibitor Narrow-spectrum Bacteriostatic

Narrow-spectrum

Why would a person take probiotics when undergoing a course of antibiotic treatment? To reduce the stomach pain commonly experienced when taking antibiotics To increase the positive effects of the antibiotics To prevent any opportunistic infections that may arise To help with weight management

To prevent any opportunistic infections that may arise

Staphylococcus aureus and MRSA are commonly associated with _____. the flu wound infections water contamination headaches

wound infections