Chapter 14 Study Guide

Question 1

Selectively finding and destroying pathogens without damaging the host

Answer 1

Selective toxicity

Question 2

The goal is to have antimicrobial agent attack unique features of the pathogen leaving the hosts cells unaffected

Answer 2

Selective toxicity

Question 3

Why is it generally more difficult to develop anti microbials for eukaryotic and viral infections

Answer 3

Similarity to host cells
Intracellular nature of viruses
Fewer unique targets
High mutation rates

Question 4

What was the first anti microbial to be developed

Answer 4

Penicillin

Question 5

Is better called anti microbial because it targets a wide range of microbes, including bacteria.

Answer 5

Penicillin

Question 6

What is the difference between a synthetic and a semi synthetic drug ?

Answer 6

Synthetic is made in a lab or not found in nature

Semi synthetic is chemically modified derivative of a natural antibiotic

Question 7

The first true antibiotic discovered was _______. It was discovered by ______.

Answer 7

Penicillin

Alexander Fleming

Question 8

Cause reverse inhibition of growth, with bacterial growth restarting after elimination of the drug.

Answer 8

Bacteriostatic

Question 9

Drugs kill their target bacteria

Answer 9

Bactericidal

Question 10

A ______ targets only specific subsets of bacterial pathogens.

If the pathogen causing an infection has been identified, it is best to use ________.

Answer 10

Narrow spectrum antimicrobial

Question 11

A __________ targets a wide variety of bacterial pathogens, including both gram positive and gram negative.

Answer 11

Broad spectrum

Question 12

The risk associated with using broad spectrum antimicrobials that they will also target a broad spectrum of the normal microbiota, increasing the risk of a _________, a secondary infection in a patient having a preexisting infection.

Answer 12

Superinfection

Question 13

A _______ develops when the antibacterial intended for preexisting infection kills the protective microbiota, allowing another pathogen resistant to the antibacterial to proliferate and cause a secondary infection.

Answer 13

Superinfection

Question 14

What are the 5 main mechanisms of actions of antibiotics

Answer 14

Inhibit cell wall synthesis
Inhibit protein synthesis
Disruption of cell membrane
Inhibit nucleic acid synthesis
Inhibit metabolic pathways

Question 15

Which of the 5 mechanisms of actions does penicillin use ?

Answer 15

Inhibit cell wall synthesis

Question 16

Have a broader spectrum of effectiveness compared to penicillin. They can target a wider range of bacteria, including some gram negative bacteria.

Answer 16

Ampicillin and amoxicillin

Question 17

Is a semisynthetic penicillin that was developed to address the spread of enzymes that were inactivating the other penicillins

Answer 17

Methicillin

Question 18

Why is penicillin called a B-lactam antibiotic ?

Answer 18

It contains a B lactam ring that interferes with enzymes that bacteria use to build their cell walls

Question 19

Examples of B lactam antibiotics

Answer 19

Penicillins
Cephalosporins
Monobactams
Carbapenems

Question 20

A _______ enzyme breaks down the B lactam ring in B lactam antibiotics, rendering them ineffective against bacteria that produce this enzyme

Answer 20

B lactamase

Question 21

Tetracyclines and erythromycin kill microbes by

Answer 21

Inhibiting protein synthesis

Question 22

These drugs target bacterial ribosomes that have 70s ribosomes

Answer 22

Tetracycline and erythromycin

Question 23

Fluoroquinolones like ciproflaxin, use the mechanism of ________?

Answer 23

Inhibition of nucleic acids

Question 24

Inhibit folic acid synthesis

Answer 24

Sulfonamides

Question 25

Is effective against a wide range of bacteria, including gram positive organisms found on the skin, such as staphylococcus and streptococcus

Answer 25

Bacitracin

Question 26

Is effective against a wide range of bacteria, including gram positive organisms found on the skin, such as staphylococcus and streptococcus

Answer 26

Bacitracin

Question 27

Why is targeting ergosterol in fungi effective for these kinds of infections ?

Answer 27

Ergosterol is similar to cholesterol, it maintains cell membrane integrity and function

Question 28

Do human cells have ergosterol ?

Answer 28

No, this makes ergosterol a unique target for anti fungal drugs allowing selective toxicity

Question 29

Should only be used for life threatening fungal infections because it can also bind to cholesterol, potentially causing kidney damage

Answer 29

Amphotericin B

Question 30

What are some of the primary targets for anti viral medications ?

Answer 30

Block the receptor ps on the host cell that bind to the virus Block fusion of the virus and cell

Question 31

Specifically target influenza viruses by blocking the activity of influenza virus neuraminidase, preventing the release of the virus from infected cells.

Answer 31

Tamiflu Relentza Rapivab

Question 32

Which pathogen are antiretroviral drugs used for ?

Answer 32

HIV

Question 33

Also interferes with anaerobic bacteria Treats trichomonas, giardiasis, and amebic dysentery

Answer 33

Metronidazole

Question 34

Is when bacteria evolve to survive exposure to antibiotics that would normally kill them or stop their growth

Answer 34

Antibiotic resistance

Question 35

What are the 4 most common mechanisms of antibiotic resistance

Answer 35

Blocking entry Inactivation by enzymes Alteration of target molecule Efflux of antibiotic

Question 36

Three major ways to test for susceptibility to antimicrobials

Answer 36

Disk diffusion method Broth dilution test E-test

Question 37

The ______ establishes the MIC, determining the lowest concentration of an antimicrobial that inhibits visible bacterial growth

Answer 37

Broth dilution test

Question 38

Bacteria that are resistant to large number of antibiotics

Answer 38

Superbugs

Question 39

Are colloquially known as “superbugs” and carry one or more resistance mechanisms, making them resistant to multiple antimicrobials

Answer 39

MDR multi drug resistant microbes

Question 40

Why is there a concern ? Resistant to many common antibiotics, limiting treatment options

Answer 40

MRSA

Question 41

Resistant to vancomycin, a last resort antibiotics

Answer 41

VRE and VRSA

Question 42

Resistant to the most potent TB drugs, leading to longer, more complex treatments with a higher risk of failure.

Answer 42

MDR-TB and XDR-TB

Question 43

What are some potential safety issues associated with antimicrobial drugs ?

Answer 43

Allergy Therapeutic index Reactions of antibiotics with other drugs Damage to organs Risk to fetus

Question 44

The effect of two drugs together is greater than the effect of either alone

Answer 44

Synergism

Question 45

The effect of two drugs together is less than the effect of either alone

Answer 45

Antagonism

Question 46

The lowest concentration of drug that inhibits visible bacterial growth

Answer 46

MIC minimal inhibitory concentration

Question 47

The broth dilution test and the E test can determine the

Answer 47

MIC minimal inhibitory concentration

Question 48

Reports that record susceptibility of organisms encountered clinically

Answer 48

Antibiograms

Question 49

A substance produced by a microbe that, in small amounts, inhibits another microbe.

Answer 49

Antibiotic

Question 50

Synthetic substances that interfere with the growth of microbes

Answer 50

Antimicrobial

Question 51

The _______ antibacterials block the cross linking of pepetide chains during the biosynthesis of new peptidoglycan in the bacterial cell wall

Answer 51

B lactam drug

Question 52

Penicillins, cephalosporins, monobactams, and carbapenems all contain a B lactam ring, the site of attack by inactivating _________

Answer 52

B lactamase enzymes

Question 53

The use of chemicals to treat a disease

Answer 53

Chemotherapy

Question 54

Are a class of antibiotics used to treat various bacterial infections. They work by inhibiting bacterial DNA synthesis, effectively killing the bacteria. Ex. Ciproflaxin and Levoflaxin

Answer 54

Fluoroquinolone

Question 55

Produced by viral infected cells to inhibit further spread of infection

Answer 55

Interferons

Question 56

Prevent the synthesis of peptidoglycan

Answer 56

Penicillins

Question 57

A scientist discovers that a soil bacterium he has been studying produces an antimicrobial that kills gram-negative bacteria. She isolates and purifies the antimicrobial compound, then chemically converts a chemical side chain to a hydroxyl group. When she tests the antimicrobial properties of this new version, she finds that this antimicrobial drug can now also kill gram positive bacteria. The new antimicrobial drug with broad-spectrum activity is considered to be which of the following?

Answer 57

semisynthetic

Question 58

Which of the following antimicrobial drugs is synthetic?

Answer 58

sulfanilamide

Question 59

Which of the following combinations would most likely contribute to the development of a superinfection?

Answer 59

Long-term use of broad-spectrum antimicrobials

Question 60

Which of the following routes of administration would be appropriate and convenient for home administration of an antimicrobial to treat a systemic infection?

Answer 60

oral

Question 61

Which clinical situation would be appropriate for treatment with a narrow-spectrum antimicrobial drug?

Answer 61

Treatment of strep throat caused by culture-identified Streptococcus pyogenes

Question 62

Which of the following terms refers to the ability of an antimicrobial drug to harm the target microbe without harming the host?

Answer 62

selective toxicity

Question 63

Which of the following is not a type of β-lactam antimicrobial?

Answer 63

Glycopeptides

Question 64

Which of the following does not bind to the 50S ribosomal subunit?

Answer 64

Tetracyclines

Question 65

Which of the following is not an appropriate target for antifungal drugs?

Answer 65

cholesterol

Question 66

Which of the following drug classes specifically inhibits neuronal transmission in helminths?

Answer 66

avermectins

Question 67

In the Kirby-Bauer disk diffusion test, the _______ of the zone of inhibition is measured and used for interpretation.

Answer 67

diameter

Question 68

Which of the following techniques cannot be used to determine the minimum inhibitory concentration of an antimicrobial drug against a particular microbe?

Answer 68

kirby bauer disk

Question 69

The utility of an antibiogram is that it shows antimicrobial susceptibility trends

Answer 69

In a localized population.

Question 70

An ______ is used to show antimicrobial susceptibility trends in a specific, localized population, such as a hospital or community, helping guide empirical therapy and monitor resistance patterns within that area.

Answer 70

antibiogram

Question 71

Which of the following has yielded compounds with the most antimicrobial activity?

Answer 71

soil

Question 72

Narrow-spectrum antimicrobials are commonly used for prophylaxis following surgery.

Answer 72

false

Question 73

β-lactamases can degrade vancomycin.

Answer 73

false

Question 74

Echinocandins, known as “penicillin for fungi,” target β(1→3) glucan in fungal cell walls.

Answer 74

true

Question 75

The rate of discovery of antimicrobial drugs has decreased significantly in recent decades.

Answer 75

true

Question 75

If drug A produces a larger zone of inhibition than drug B on the Kirby-Bauer disk diffusion test, drug A should always be prescribed.

Answer 75

false

Question 76

The bacterium known for causing pseudomembranous colitis, a potentially deadly superinfection, is ________.

Answer 76

c. diff

Question 77

Selective toxicity antimicrobials are easier to develop against bacteria because they are ________ cells, whereas human cells are eukaryotic.

Answer 77

prokaryotic

Question 78

Antiviral drugs, like Tamiflu and Relenza, that are effective against the influenza virus by preventing viral escape from host cells are called

Answer 78

neuraminidase inhibitors.

Question 79

Staphylococcus aureus, including MRSA strains, may commonly be carried as a normal member of the ________ microbiota in some people.

Answer 79

nasal microbiota

Question 80

The method that can determine the MICs of multiple antimicrobial drugs against a microbial strain using a single agar plate is called the ________.

Answer 80

E test

Question 81

Where do antimicrobials come from naturally? Why?

Answer 81

bacteria and fungi;

Question 82

How does the biology of HIV necessitate the need to treat HIV infections with multiple drugs?

Answer 82

high mutation rate

Question 83

What bacterial structural target would make an antibacterial drug selective for gram-negative bacteria? Provide one example of an antimicrobial compound that targets this structure.

Answer 83

The outer membrane of gram-negative bacteria is a key structural target for selective antibacterial drugs. An example of an antimicrobial compound that targets this structure is polymyxin B.

Question 84

inhibiting cell wall synthesis _____ prevent the synthesis of peptidoglycan

Answer 84

penicillin

Question 85

inhibiting protein synthesis– Target bacterial 70S ribosomes

Answer 85

Chloramphenicol, erythromycin, streptomycin, tetracyclines