Deck 27: Antimicrobial Chemotherapy

Question 1

An MIC result of 10µg 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 the 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.

Answer 1

Bacterial strain A is more susceptible to penicillin than the others.

Question 2

Which of the following would be best to target a new antibiotic to?

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

Answer 2

E

Question 3

The Mueller-Hinton medium used in the Kirby

Answer 3

E

Question 4

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 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 0.5 McFarland standard is used in all microbiology labs when performing a Kirby

Question 7

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 8

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 9

Which of the following statements about the Kirby

Question 10

A bacteria that is penicillin resistance can be 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

Question 11

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

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

Question 12

If you wanted to isolate a molecule of vancomycin from nature, what microbe would you need to culture?

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

Question 13

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 14

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

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

Question 15

The minimal inhibitory concentration is the:

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

Question 16

An MIC test can determine all EXCEPT for which of the following?

A) lowest level of an antibiotic that kills a particular bacteria
B) 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) bacteriostatic or bactericidal drugs

Question 17

Bacterial peptidoglycan formation uses all EXCEPT for which of the following components?

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

Question 18

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

Question 19

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

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

Question 20

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) bacteriocompetant

Question 21

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 22

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) neither can form individual cells or biofilms
E) cycle between animal and human populations, never dying out

Question 23

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

A) aminoglycoside
B) ampicillin
C) tetracycline
D) bactracin
E) quinolone

Question 24

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 pneumonia
B) Staphylococcus aureas
C) Mycobacterium tuberculosis
D) Escherichia coli
E) Plasmodium falciparum

Question 25

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 26

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 27

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 foodborne 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/targets
E) administer antibiotics more prudently when possible

Question 28

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 29

Saccharopolyspora erythraea, the organism that produces the antibiotic Eyrthromycin, is synthesized using a biochemical pathway similar to:

A) peptidoglycan synthesis
B) fatty acid synthesis
C) ribosomal RNA synthesis
D) purine and pyrimidine synthesis
E) flagella synthesis

Question 30

The multidrug resistance (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 31

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

Question 32

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 33

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 34

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 35

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 36

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) MDR enhancers

Question 37

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

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

Question 38

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 39

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 40

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

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

Question 41

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 42

Platensimycin is a novel antibiotic that was recently discovered. It has all 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 proteins.

Question 43

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 44

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

Question 45

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

Question 46

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 47

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 48

A novel antibiotic, discovered to treat bloodborne bacteria during sepsis infection, is found to have a dramatic effects 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 49

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 50

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

Question 51

Quorum sensing is a new approach to antibiotic therapy that works by:

A) preventing horizontal transfer of genes
B) stopping bacterial motility
C) binding virulence transcription factors
D) halting bacterial cell-cell communications
E) regulating nutrient uptake to decrease metabolism

Question 52

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

A) 5 or more different non-nucleoside reverse transcriptase inhibitors
B) 3 or more different nucleoside reverse transcriptase inhibitors
C) 4 or more different integrase inhibitors
D) 2 or more different protease inhibitors
E) 2 or more different nucleoside, non-nucleoside, and protease inhibitors

Question 53

Influenza envelope neuraminidase (NA) 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 54

Explain why Metronidazole is NOT effective against an aerobic bacteria like Staphylococcus aureas?

Question 55

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

Question 56

The antiviral nucleoside inhibitor, Stavudine, 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 inactivates enzyme
E) sterically hindering integrase from cutting into the host nuclear DNA

Question 57

The term "herd immunity" when used to describe the 2009 H1N1 epidemic refers to:

A) the fact that this pandemic started on bird farms in Asia
B) this swine flu epidemic 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 city children

Question 58

Many times people will tell you to eat yogurt or drink kefir if you are on antibiotics, why is this and is this just an "urban legend"?

Question 59

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

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

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

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

Question 62

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 63

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 aureas (MRSA).

Question 64

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

Question 65

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 66

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 67

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

Question 68

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

Question 69

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