LEC 15 - Introduction to Chemotherapy Flashcards

1
Q

What bacterial group is most commonly the ones that undergo conjugation?

A

Gram-negative

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2
Q

What drugs cannot be used in food animals? (8)

A

Fluoroquinolones

Chloramphenicol

Nitroimidazoles

Furazolidone

Nitrofurazone

Nitrofurans

Sulfonamides - lactating cattle

Vancomycin

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3
Q

Mechanism of action - Macrolides

A

50S

Inhibits translocation

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4
Q

Drugs for: Cell membrane

A

Polymyxins

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5
Q

Component of transformation -

A

Free DNA

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6
Q

What are the five chemotherapy agents that cause renal toxicity?

A

Cephalosporins

Vancomycin

Aminoglycosides

Sulfonamides

Amphotericin

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7
Q

Mutation type for Quinolone resistance?

A

Gyrase gene mutation

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8
Q

Mechanism of resistance - Beta lactams

A

Penicillinase

Modification of PBP’s

Change of porins

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9
Q

How is Staph Aureus resistant?

A

Penicllinase via a plasmid

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10
Q

Mechanism of action - Fluoroquinolones

A

Inhibiting topoisomerase

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11
Q

How is multiple drug resistance transmitted between bacteria?

A

Plasmids

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12
Q

How does conjugation pass along antibacterial resistance?

A

Passage of genes from cell to cell by DIRECT CONTACT through sex pilus or bridge

Can spread multi-drug resistance

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13
Q

How does transformation cause resistance to be passed along?

A

Incorporation of DNA that has been found free in the environment into the bacterial genome

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14
Q

What are the eight chemotherapy agents that cause hepatotoxicty?

A

Tetracyclines

Erthromycin estolate

Clindamycin

methotrexate

6-mercaptopurine

Sulfonamides

Amphotericin B

Doxorubicin

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15
Q

What are the two chemotherapy agents that cause photosensitivity?

A

Tetracyclines

Fluroquinolones

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16
Q

Component of conjugation -

A

Transfer of genes through sex pilus

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17
Q

Describe bactericidal activity

A

No remarkable difference between bacteriostatic and bactericidal concentrations

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18
Q

Drugs for: Protein synthesis 50s

A

Erythromycin

Chloramphenico

Clindamycin

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19
Q

What are the three methods by which horizontal transfer can occur?

A

Transformation

Transduction

Conjugation

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20
Q

Mechanism of action - Sulfonamides

A

Inhibition of folic acid synthesis

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21
Q

What are the two drugs that can cause hemolytic anemias?

A

Sulfonamides

Nitrofurantoin

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22
Q

What are the ways resistance can be acquired?

A

Vertically

Horizontially

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23
Q

Drugs for: DNA-Dependent RNA polymerase

A

Rifampin

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24
Q

Mechanism of action - Chloramphenicol

A

50S

Inhibit transpeptidation

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25
Q

What are the three antibacterial agents that have become useless due to an increase in resistance in previously susceptible cells?

A

Streptomycin

Quinolones

Rifampin

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26
Q

What are the six mechanisms that a bacteria can be resistant to a drug?

A

Fails to absorb drug

Inactivates the drug

Pumps out drug

Target to drug is modified

Increased production of target molecules

Altered metabolic pathway bypassing drug target

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27
Q

Mechanism of resistance - Sulfonamides

A

Decreased sensitivity of the target enzymes

increased formation of PABA

Use of exogenous folate

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28
Q

Drugs for: DNA replication

A

Nalidixic acid

Quinolones

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29
Q

What are the major adverse affects that occur with chemotherapy agents?

A

overextenstion of actions

organ directed toxcity

Hypersensitivy reactions

30
Q

Mechanism of resistance - Aminoglycocides

A

Acetyl

Phophosryl

Adenylyl conjugation

31
Q

Mechanism of resistance - Chloramphenicol

A

Inactivating acetyltransferases

32
Q

What is a common resistance that occurs with transformation? What bacterial types?

A

Penicillin resistance

Pneumococci + Neisseria

33
Q

Mechanism of action - Tetracyclines

A

30S

Prevent binding the incoming charged tRNA

34
Q

What are the three drugs that cause ototoxicity?

A

Aminoglycosides

Vancomycin

Minocycline

35
Q

Mechanism of resistance - Tetracyclines

A

Pump out

36
Q

Why is it important to reach and maintain adequate blood levels of a chemotherapy agent?

A

Prevents the development of resistance

37
Q

What is the mechanism that Penumococci is resistant to penicillin?

A

Produce altered penicillin-binding proteins that have low affinity binding of penicillin

38
Q

Why is sulfonamides such a concern in food animals?

A

Accumulate in the kidney

Withdrawl times are long + highly variable

39
Q

What method of acquired resistance is the most succesful

A

Plasmid involved resistance -

When entered into the genome of the bacteria only 50% off the daughter cells will get the mutation

40
Q

What does it mean for a drug to be time dependent when it comes to killing?

A

Killing is not increased with increasing concentrations about MBC

41
Q

What two bacterias commonly use conjugation for passing along resistance?

A

Shigella + Enterobacteriaceae

Can exchange between one another as well

42
Q

Mechanism of resistance - Vancomycin

A

Change in pentapeptide

D-ala-D lactate

43
Q

What antibactieral agents is Staph Aureus resistant to?

A

Eryhtromycin

Tetracycline

Chloramphenicol

44
Q

Mechanism of resistance - Macrolides

A

Methyltransferase alters the binding site

45
Q

Mechanism of action - Beta Lactams

A

Inhibition of bacterial cell wall synthesis

46
Q

Drugs for: Folic acid metabolism

A

Trimethoprim

Sulfonamides

47
Q

Component of transduction -

A

Bacteriophages

48
Q

Mechanism of resistance - Rifampin

A

Change in enzyme

49
Q

What are the two methods by which bactericidal agents kill?

A

Concentration dependent

Time dependent

50
Q

Drugs for: Protein synthesis - 30s

A

Tetracycline

Spectinomycin

Sterptomycin

Gentamincin/Tobramycin

Amikacin

51
Q

What two drugs are concentration dependent?

A

Aminoglycocides

Quinolones

52
Q

What does it mean for a bactericidal agent to be conentration dependent killing?

A

Rate and extent of killing dependent upon drug concentration

53
Q

Mutation type in Rifampin resistance?

A

RNA polymerase gene mutation

54
Q

What are the four ways that allergic reactions to these chemotherapy agents might present?

A

Anaphylactic shock

Skin rashes

Immune induced blood dyscrasias

Immune hemolytic anemias

55
Q

Where does conjugation tend to take place?

A

Intestinal tract - between nonpathogenic and pathogenic microorganisms

56
Q

How does transduction cause resistance?

A

Invervention of a bacteriophage that has bacterial DNA incorporated within the protein coat

57
Q

Mutation type for streptomycin resistance?

A

Ribosomal mutation

58
Q

What are the two specific agents that are known to be hemopoietically toxic?

A

Chloramphenicol

Sulfonamides

59
Q

What are the special components to chemotherapy?

A

Selective toxicity (Parasite > Host)

Selects for resistant strains

Hypersensitivity + Organ directed toxicity

Lowers microorganism load (Host defense does the rest)

60
Q

Drugs for: Periplasmic space

A

B-lactamases

Aminoglycosides

61
Q

What two drugs are time dependent when it comes to their -cidal effects?

A

Beta-lactams

Vancomycin

62
Q

What is exchanged in conjugation between bacteria?

A

R-determinant plasmid

risstance transfer factor (RTF)

63
Q

Describe bacteriostatic drugs

A

Bacteriostatic concentrations much lower than bactericidal

64
Q

What drug is there a voluntary ban in food animals?

A

Sulfonamides

65
Q

Mechanism of resistance - Fluoroquinolones

A

Change in sensitivity of TI

“Pump out”

66
Q

Drugs for: Cell wall synthesis

A

Cycloserine

Vancomycin

Bactitracin

Penicillins

Cephalosporins

67
Q

Mechanism of action - Vancomysin

A

Inhibition of peptidoglycan chain elongation

68
Q

Mechanism of action - Aminoglycosides

A

30S

Blocks initiation

Elicits premature termination by incorporating incorrect AA

69
Q

Mechanism of action - Rifampin

A

Inhibits DNA dependent RNA polymerase

70
Q

What bacteria is known for using transduction to spread resistance?

A

Staph. Aureus

71
Q

When is maintaince of constant blood levels most important?

A

With bacteriostatic drugs more so than bactericidal

72
Q

How is resistance vertically passed?

A

Mutation occurs

Passed to offspring by selection