LEC 15 - Introduction to Chemotherapy Flashcards Preview

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Flashcards in LEC 15 - Introduction to Chemotherapy Deck (72):
1

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

Gram-negative 

2

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

Fluoroquinolones 

Chloramphenicol 

Nitroimidazoles 

Furazolidone 

Nitrofurazone 

Nitrofurans 

Sulfonamides - lactating cattle 

Vancomycin 

3

Mechanism of action - Macrolides

50S 

Inhibits translocation

4

Drugs for: Cell membrane 

Polymyxins

5

Component of transformation - 

Free DNA 

6

What are the five chemotherapy agents that cause renal toxicity?

Cephalosporins 

Vancomycin 

Aminoglycosides 

Sulfonamides 

Amphotericin 

7

Mutation type for Quinolone resistance?

Gyrase gene mutation 

8

Mechanism of resistance - Beta lactams

Penicillinase 

Modification of PBP's 

Change of porins

9

How is Staph Aureus resistant?

 Penicllinase via a plasmid 

10

Mechanism of action - Fluoroquinolones

Inhibiting topoisomerase 

11

How is multiple drug resistance transmitted between bacteria?

Plasmids

12

How does conjugation pass along antibacterial resistance?

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

Can spread multi-drug resistance

13

How does transformation cause resistance to be passed along?

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

14

What are the eight chemotherapy agents that cause hepatotoxicty?

Tetracyclines 

Erthromycin estolate 

Clindamycin 

methotrexate 

6-mercaptopurine 

Sulfonamides 

Amphotericin B 

Doxorubicin 

15

What are the two chemotherapy agents that cause photosensitivity?

Tetracyclines 

Fluroquinolones 

16

Component of conjugation - 

Transfer of genes through sex pilus 

17

Describe bactericidal activity 

No remarkable difference between bacteriostatic and bactericidal concentrations

18

Drugs for: Protein synthesis 50s 

Erythromycin 

Chloramphenico 

Clindamycin 

 

19

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

Transformation 

Transduction 

Conjugation 

20

Mechanism of action - Sulfonamides

Inhibition of folic acid synthesis 

21

What are the two drugs that can cause hemolytic anemias?

Sulfonamides 

Nitrofurantoin 

22

What are the ways resistance can be acquired?

Vertically 

Horizontially 

23

Drugs for: DNA-Dependent RNA polymerase 

Rifampin 

24

Mechanism of action - Chloramphenicol

50S

Inhibit transpeptidation 

25

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

Streptomycin 

Quinolones 

Rifampin 

26

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

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

27

Mechanism of resistance - Sulfonamides

Decreased sensitivity of the target enzymes 

increased formation of PABA 

Use of exogenous folate

28

Drugs for: DNA replication

Nalidixic acid 

Quinolones 

29

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

overextenstion of actions 

organ directed toxcity 

Hypersensitivy reactions

30

Mechanism of resistance - Aminoglycocides 

Acetyl 

Phophosryl 

Adenylyl conjugation

31

Mechanism of resistance - Chloramphenicol

Inactivating acetyltransferases

32

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

Penicillin resistance 

Pneumococci + Neisseria 

33

Mechanism of action - Tetracyclines 

30S 

Prevent binding the incoming charged tRNA 

34

What are the three drugs that cause ototoxicity?

Aminoglycosides 

Vancomycin 

Minocycline

35

Mechanism of resistance - Tetracyclines

Pump out 

36

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

Prevents the development of resistance 

37

What is the mechanism that Penumococci is resistant to penicillin?

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

38

Why is sulfonamides such a concern in food animals?

Accumulate in the kidney 

Withdrawl times are long + highly variable 

39

What method of acquired resistance is the most succesful 

Plasmid involved resistance - 

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

40

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

Killing is not increased with increasing concentrations about MBC 

 

41

What two bacterias commonly use conjugation for passing along resistance? 

Shigella + Enterobacteriaceae 

Can exchange between one another as well 

42

Mechanism of resistance - Vancomycin 

Change in pentapeptide 

D-ala-D lactate

43

What antibactieral agents is Staph Aureus resistant to?

Eryhtromycin 

Tetracycline 

Chloramphenicol 

44

Mechanism of resistance - Macrolides

Methyltransferase alters the binding site 

45

Mechanism of action - Beta Lactams 

Inhibition of bacterial cell wall synthesis 

46

Drugs for: Folic acid metabolism

Trimethoprim 

Sulfonamides

47

Component of transduction - 

Bacteriophages

48

Mechanism of resistance - Rifampin 

Change in enzyme

49

What are the two methods by which bactericidal agents kill?

Concentration dependent 

Time dependent

50

Drugs for: Protein synthesis - 30s 

Tetracycline 

Spectinomycin 

Sterptomycin 

Gentamincin/Tobramycin 

Amikacin 

51

What two drugs are concentration dependent?

Aminoglycocides 

Quinolones

52

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

Rate and extent of killing dependent upon drug concentration 

 

53

Mutation type in Rifampin resistance?

RNA polymerase gene mutation 

54

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

Anaphylactic shock 

Skin rashes 

Immune induced blood dyscrasias 

Immune hemolytic anemias 

55

Where does conjugation tend to take place?

Intestinal tract - between nonpathogenic and pathogenic microorganisms

56

How does transduction cause resistance?

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

57

Mutation type for streptomycin resistance?

Ribosomal mutation 

58

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

Chloramphenicol 

Sulfonamides 

59

What are the special components to chemotherapy?

Selective toxicity (Parasite > Host) 

Selects for resistant strains 

Hypersensitivity + Organ directed toxicity 

Lowers microorganism load (Host defense does the rest)

60

Drugs for: Periplasmic space

B-lactamases

Aminoglycosides 

 

61

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

Beta-lactams 

Vancomycin

62

What is exchanged in conjugation between bacteria?

R-determinant plasmid 

risstance transfer factor (RTF) 

63

Describe bacteriostatic drugs 

Bacteriostatic concentrations much lower than bactericidal 

64

What drug is there a voluntary ban in food animals?

Sulfonamides

65

Mechanism of resistance - Fluoroquinolones

Change in sensitivity of TI 

"Pump out" 

66

Drugs for: Cell wall synthesis 

Cycloserine 

Vancomycin 

Bactitracin 

Penicillins 

Cephalosporins 

67

Mechanism of action - Vancomysin 

Inhibition of peptidoglycan chain elongation 

68

Mechanism of action - Aminoglycosides 

30S 

Blocks initiation 

Elicits premature termination by incorporating incorrect AA

69

Mechanism of action - Rifampin 

Inhibits DNA dependent RNA polymerase

70

What bacteria is known for using transduction to spread resistance?

Staph. Aureus 

71

When is maintaince of constant blood levels most important?

With bacteriostatic drugs more so than bactericidal 

72

How is resistance vertically passed?

Mutation occurs 

Passed to offspring by selection