Deck 27: Antimicrobial Therapy

Question 1

A patient who accidentally takes too many doses of chloramphenicol during a Salmonella sp. infection could possible come down with:

A) aplastic anemia
B) liver cancer
C) gastroenteritis
D) ulcers
E) growth plate defects

Answer 1

A

Question 2

An example of an antibiotic that binds to the 30S ribosomal subunit would be:

A) streptogramins
B) macrolides
C) beta-lactams
D) fluoroquinolones
E) aminoglycosides

Answer 2

E

Question 3

A bacterium may be penicillin resistant due to all of the following EXCEPT:

A) Gram-negative cell wall
B) beta-lactase production
C) Gram-positive cell wall
D) modified transpeptidases
E) modified transglycosylases

Answer 3

C

Question 4

If a drug were designed that only seemed to affect the growth of Burkholderia pseudomallei, this drug would be considered:

A) broad range
B) uni-narrow range
C) slightly narrow range
D) extremely narrow range
E) species sensitive range

Question 5

A newly isolated antibiotic that kills Klebsiella sp. was found in soil bacteria. Chemical analysis showed the structure of this molecule to contain a cysteine/valine ring structure. This new antibiotic would be classified as a:

A) metabolic inhibitor
B) cell membrane inhibitor
C) protein-synthesis inhibitor
D) DNA synthesis inhibitor
E) cell wall inhibitor

Question 6

A standardized inoculum of bacteria is used in all microbiology labs when performing a Kirby

Question 7

The bacteria killed in Alexander Fleming's experiment during his discovery of penicillin were:

A) Pseudomonas aeruginosa
B) Escherichia coli
C) Staphylococcus aureas
D) Streptococcus pyogenes
E) Klebsiella pneumonia

Question 8

Infections that are acquired during a stay in a hospital are called:

A) clinical
B) nosocomial
C) gnotobiotic
D) resistant
E) pathogenic

Question 9

Which of the following is a drug treatment typically given in the case of a surgical infection contaminated with MRSA?

A) oral penicillin
B) intramuscular sulfamididine
C) intravenous vancomycin
D) subcutaneous isoniazid
E) intraperitoneal streptomycin

Question 10

Which of the following statements about the Kirby

Question 11

Which of the following would be the best target for development of a new antibitotic?

A) phospholipids in plasma membrane
B) glycolysis pathway
C) pyrimidine bases
D) nuclear envelope
E) ribosomes

Question 12

Bacterial peptidoglycan formation uses all of the following components EXCEPT:

A) N-acetylmuramic acid
B) uridine diphosphate
C) bactoprenol
D) hopanoid
E) N-acetylglucosamine

Question 13

Minimal inhibitory concentration, or MIC, is:

A) the average concentration of a drug that will prevent the growth of an organism
B) the lowest concentration of a drug that will prevent the growth of an organism
C) the highest concentration of a drug that will prevent the growth of an organism
D) the midline concentration of a drug that will prevent the growth of an organism
E) any concentration of a drug that will prevent the growth of an organism

Question 14

Streptogramins are a drug class that possess a synergistic effect. This means that they:

A) work best on antibiotic-resistant and antibiotic-intermediate bacteria
B) kill bacteria using both bacteriostatic and bactericidal mechanisms
C) have two drug components working together to create a more potent effect
D) induce an antibody-driven immune response more quickly
E) kill Gram-negative, Gram-positive, and mycobacteria equally well

Question 15

An MIC test can determine all of the following EXCEPT:

A) the lowest level of an antibiotic that kills a particular bacteria
B) the highest level of an antibiotic that kills a particular bacteria
C) levels of an antibiotic that do not kill a particular bacteria
D) drug susceptibility and resistance
E) whether the drug is bacteriostatic or bactericidal

Question 16

Salvarsan is an arsenical compound used to target which of the following pathogens?

A) Treponema pallidum
B) Plasmodium falciparium
C) Escherichia coli
D) Streptococcus mutans
E) Mycobacterium tuberculosis

Question 17

The Mueller-Hinton medium used in the Kirby

Question 18

Which of the following is an antibiotic that prevents the synthesis of tetrahydrofolic acid within the bacterial cell?

A) translation inhibitor
B) cell wall inhibitor
C) bacterial membrane inhibitor
D) DNA synthesis inhibitor
E) RNA synthesis inhibitor

Question 19

A drug designed to poke holes into the plasma membrane of a Pseudomonas aeruginosa bacteria would best be considered:

A) bactericidal
B) microbe-sensitive
C) semiselective
D) bacteriostatic
E) bacteriocompetent

Question 20

An MIC result of 10 µg of penicillin for bacterial strain A, 15 $\mu$ g for stain B, 18 $\mu$ g for strain C, and 27 $\mu$ g of penicillin for strain D can be interpreted as which of the following?

A) Bacterial strain A is more susceptible to penicillin than the others.
B) Bacterial strain B is more susceptible to penicillin than the others.
C) Bacterial strain C is more susceptible to penicillin than the others.
D) Bacterial strain D is more susceptible to penicillin than the others.
E) All strains are equally susceptible.

Question 21

Which of the following would NOT be considered a way to fight bacterial resistance?

A) creating molecules without antibiotic activity that can compete and bind antibiotic-resistance enzymes
B) increase the amount of antibiotics in our foods to prevent food-borne infection
C) alter the structure of antibiotics to sterically hinder the binding of antibiotic-resistance enzymes
D) link different antibiotics together, forming hybrid antibiotics with dual action and targets
E) administer antibiotics more prudently when possible

Question 22

Bactrim, a sulfa drug used to treat urinary tract infections, does NOT harm host cells because eukaryotic cells:

A) have efflux pumps for the drug
B) take in folic acid in the diet
C) do not transport the drug into the cell
D) are naturally immunized from the drug
E) make their own PABA precursors

Question 23

A bacterial strain exhibiting a DNA gyrase mutation would most likely inhibit the activity of what class of antibiotics?

A) metronidazoles
B) tetracyclines
C) quinolones
D) cephalosporins
E) sulfa drugs

Question 24

One way a macrolide-producing organism, such as Streptomyces sp., prevents its own demise from production of the antibiotic is to:

A) methylate its own RNA
B) change its peptidoglycan linkages
C) create an MDR pump
D) change its DNA structure
E) only produce the antibiotic during the death phase

Question 25

Which of the following is a clinically important lung bacteria that kills approximately 2 million people annually and is becoming increasingly multidrug resistant?

A) Streptococcus pneumoniae
B) Staphylococcus aureas
C) Mycobacterium tuberculosis
D) Escherichia coli
E) Plasmodium falciparum

Question 26

Gene-expression elements that account for rapid transmission of drug resistance due to their mobility and ability to collect resistance gene cassettes are called:

A) mobile units
B) virulence plasmids
C) integrons
D) insertion prophages
E) multidrug resistant enhancers

Question 27

A recently synthesized molecule demonstrates the ability to bind tightly to bactoprenol. This molecule is most closely similar to:

A) cycloserine
B) vancomycin
C) bacitracin
D) penicillin
E) cephalosporin

Question 28

The multidrug resistance, or MDR, efflux pumps found in organisms such as resistant strains of Escherichia coli work most similarly to:

A) ABC transporters
B) facilitated diffusion
C) reverse osmosis
D) electron transport
E) phospholipid flip-flop

Question 29

If a patient came in to your medical office with tuberculosis, a possible effective treatment for him or her has been derived from:

A) Penicillium notatum
B) Amycolatopsis orientalis
C) Staphylococcus aureas
D) Streptomyces garyphalus
E) Bacillus subtilis

Question 30

What microbe would you grow if you wanted to prepare and isolate some vancomycin?

A) Amycolatopsis orientalis
B) Staphylococcus aureas
C) Veillonella parvula
D) Streptomyces garyphalus
E) Bacillus subtilis

Question 31

A newly identified genomic target for treating penicillin-resistant Streptococcus pneumoniae is the:

A) CaPS: capsular polysaccharides
B) Ply: pneumolysin toxin
C) MotB: flagella protein
D) PGRP: peptidoglycan recognition protein
E) CbpG: pneumococcal adhesin protein

Question 32

A bacteria has evolved a new enzyme that can cleave a beta-lactam ring structure. It would NOT be treatable by which class of drugs?

A) aminoglycosides
B) ampicillin
C) tetracycline
D) bacitracin
E) quinolones

Question 33

A negative structural mutation in the norA gene in Staphylococcus aureus could have which of the following effects?

A) decreased protein synthesis
B) increased bacterial conjugation
C) decreased drug resistance
D) increased uptake of beta-lactams
E) decreased rate of clonal division

Question 34

A persister cell is an unsolved mystery of microbiology because these cells:

A) grow rapidly in the presence of antibiotics
B) neither grow or die in the presence of an antibiotic
C) cannot exit log phase growth when placed in an optimum antibiotic niche
D) can form neither individual cells nor biofilms
E) cycle between animal and human populations, never dying out

Question 35

Chemical synthesis of a new drug with a 15-member lactone ring structure would be predicted to be most similar to which antibiotic class and action?

A) gramicidin; membrane inhibitor
B) nalidixic acid; DNA inhibitor
C) actinomycin D; RNA synthesis inhibitor
D) tetracyclines; 30S inhibitor
E) macrolides; 50S inhibitor

Question 36

A bacterial strain exhibiting a unique RNA polymerase structure would most likely inhibit the activity of which antibiotic?

A) rifampin
B) nalidixic acid
C) penicillin
D) streptomycin
E) chloramphenicol

Question 37

Which of the following would NOT be a way that a Pseudomonas aeruginosa bacteria could inherit resistance genes from other bacteria?

A) transposons
B) random mutation
C) prophages
D) plasmid integration
E) integrons

Question 38

The original purpose of antibiotic production by microbes may not be known, yet for the microbes that produce antibiotic molecules, which of the following mechanisms is NOT a way to avoid self-destruction?

A) pump the antibiotic out
B) modify the target so it cannot bind
C) add modifying groups to the antibiotic
D) destroy the antibiotic
E) there is no need avoid self-destruction

Question 39

One of the leading sources of human infection by antibiotic-resistant organisms is:

A) farm animal infections
B) locker room infections
C) dental surgery infections
D) nosocomial infections
E) food recall infections

Question 40

Drugs such as cycloserine and cephalosporins work when the bacterial culture is in:

A) lag phase
B) log phase
C) stationary phase
D) death phase
E) any or all of the above bacterial phases

Question 41

A patient suffering from a systemic mycosis with aspergillosis would best be served by which antifungal?

A) imidazole
B) lamisil
C) nystatin
D) amphotericin B
E) griseofulvin

Question 42

Why is the newly discovered antibiotic class called pyronins considered to be a class of antibiotics that will be hard for a bacteria to become resistant to?

Question 43

The term "herd immunity," when used to describe an influenza epidemic, refers to:

A) the fact that this pandemic started on bird farms in Asia
B) a swine flu epidemic that is not coming from a cow population first
C) nasal immunizations working better than shot inoculations
D) vaccination measures protecting a majority of the human population
E) children living in rural areas having stronger immune systems than urban children

Question 44

What is the definition of "antibiotic"? Where are antibiotics isolated from, and why are these compounds made in nature?

Question 45

In the 1930s, Gerhard Domagk injected his own daughter with a red dye in hopes of curing her invasive streptococcal infection, even though testing of this agent on agar plates growing Streptococcus sp. showed no antimicrobial effect. Why did he do this, and what did this study show the importance of?

Question 46

Novel ideas for new antibiotic drug development do NOT include which of the following?

A) interfering with quorum-sensing mechanisms
B) "corking" the type II secretion apparatus
C) use of photosensitive chemicals to generate reactive oxygen species
D) continuing to chemically modify beta-lactams
E) use of nanotubes to poke holes in bacterial membranes

Question 47

Explain why metronidazole is NOT effective against an aerobic bacteria like Staphylococcus aureas.

Question 48

Antiviral therapy for the human immunodeficiency virus (HIV) usually consists of a protease inhibitor that inhibits what function?

A) viral exit of the newly formed virions by vial budding
B) viral fusion of the viral envelope with the host cell membrane
C) binding to the CD4 receptor on human immune cells
D) insertion of viral DNA into the host cell DNA
E) cleavage of polypeptide chains to make functional HIV viral proteins

Question 49

Compare and contrast the utility of the antibiotic polymyxin versus cephalosporin in clearing up an Escherichia coli skin infection that has become systemic.

Question 50

The influenza envelope neuraminidase viral spike protein allows the virus to:

A) escape from antibiotics
B) acidify the endocytic chamber
C) release new virions from an infected host cell
D) bind to host cell glycoproteins
E) undergo viral membrane fusion

Question 51

Many times people will tell you to eat yogurt or drink kefir if you are on antibiotics. Why do some people view this as an "urban legend"? Can it be effective?

Question 52

Why is it that the organism that produces penicillin, Penicillin notatum, it not affected by the production of this molecule, but Staphylococcus aureus is? Of what benefit is the antibiotic in the organism that created it?

Question 53

The antiviral nucleoside inhibitor zidovudine, used in treating HIV infection, works by:

A) fooling reverse transcriptase to incorporate it, causing a chain termination reaction
B) disabling protease and preventing HIV protein folding
C) blocking gag and pol genes from transcription
D) binding directly to reverse transcriptase and allosterically inactivating the enzyme
E) sterically hindering integrase from cutting into the host nuclear DNA

Question 54

A novel antibiotic, discovered to treat blood-borne bacteria during sepsis infection, is found to have a dramatic effect during MIC assays. Mice studies that followed found the drug to be cleared from the body within 15 minutes of oral administration. Would this be a good drug candidate for sepsis? Why or why not? What suggestions would you make? Support your answer.

Question 55

Genes within any one given bacteria that control growth and metabolism, both under laboratory conditions and pathogenic conditions within a host, are considered to be:

A) housekeeping genes
B) in vitro expressed genes
C) total translatable genomic genes
D) in vivo expressed genes
E) in situ expressed genes

Question 56

How is infection cleared from the body of a patient who has been prescribed antibiotics that are bacteriostatic? Give one example of a bacteriostatic antibiotic in your answer.

Question 57

There are fewer antivirals currently available from your pharmacy than there are antibacterials because:

A) bacterial cells are less complex than viruses
B) selective toxicity is much easier to achieve for bacteria
C) most antivirals available are for uncommon, life-threatening infections
D) selective toxicity is much easier to achieve for viruses
E) MIC values are larger for bacteria than for viruses

Question 58

Platensimycin is a novel antibiotic that was recently discovered. It has all of the following attributes EXCEPT:

A) it is bacteriostatic
B) it binds FabF protein found in fatty acid biosynthesis
C) it has a broad spectrum of activity
D) it works on both Gram-negative and Gram-positive bacteria
E) it targets the bacterial translation of proteins

Question 59

Antiviral therapy for the human immunodeficiency virus (HIV) usually consists of __________ to prevent resistance.

A) five or more different nonnucleoside reverse transcriptase inhibitors
B) three or more different nucleoside reverse transcriptase inhibitors
C) four or more different integrase inhibitors
D) two or more different protease inhibitors
E) two or more different nucleoside, nonnucleoside, and protease inhibitors

Question 60

A molecular microbiologist identified a unique sequence of DNA causing an amino acid shift mutation within the gene encoding for peptidoglycan transpeptidase in a clinical strain of Streptococcus pneumoniae. What does this molecule do, and of what benefit could this mutation be to the organism?

Question 61

Several antifungal therapeutic agents act to inhibit sterol synthesis. Explain why this does not affect mammalian systems.

Question 62

You are designing a new antibiotic to treat infections caused by the fungal agent Cryptococcus neoformans, a potentially fatal lung infection in patients on long-term corticosteroid therapy. What issues could you run into with selective toxicity, and what strategies would you use in your development?

Question 63

If a Staphylococcus aureas bacterium was to become resistant to a newly discovered antibiotic, what are the four basic forms of resistance this bacterium could have acquired?

Question 64

Describe the mechanism by which the influenza virus enters OR exits a host cell and one potential drug target that is being used to prevent infection.

Question 65

Why are bacteria that create biofilms so hard to destroy or clear by antibiotics or the immune system? What discoveries are being made to combat biofilm infections?

Question 66

How does prescribing a "dummy compound," like clavulanic acid, begin to address an infant bacterial infection with a Klebsiella sp. that is ampicillin-resistant?

Question 67

Outline and discuss the steps that a research laboratory would go through to discover a new antibiotic to treat a systemic infection with methicillin-resistant Staphylococcus aureus (MRSA).

Question 68

Why are drug-resistant bacteria less viable in comparison with wild type?

Question 69

How have modern agricultural practices contributed to the increase of antibiotic resistance seen today?

Question 70

How does saving the rain forest (and other endangered habitats) correlate with the fight to prevent human morbidity and mortality caused by bacterial disease? Give an example to support your argument.