Lecture 19: Introduction to Chemotherapy

Question 1

Paul Elrich discovered the ____concept and also ___for tx of sphyillus

Answer 1

Receptor effector concept, Salvarsan

Question 2

How are chemotherapy agents unique compared to other therapeutic agents based on their interaction with host and pathogen factor

Answer 2

Therapeutic agents: effect the host and host metabolizes

Chemotherapeutic agents: exert therapeutic effect on pathogen (instead of host), pathogen develops resistance. The chemo agent is metabolized by the host and chemo agent can cause toxicity to host

Question 3

What is selective toxicity

Answer 3

Greater toxicity to parasite than host

Question 4

Chemotherapy selects for ___strains

Answer 4

Resistant

Question 5

Chemotherapy lowers the ___ load so that host defense system can rid the body of foreign organisms

Answer 5

Microorganism

Question 6

Maintaining adequate blood levels is more important with bacteriostatic or bacteriocidal agents?

Answer 6

Bacteriostatic

Question 7

What are the 2 broad mechanisms in which resistance is acquired

Answer 7

Vertical and horizontal transfer

Question 8

What % of daughter cells obtain resistance via vertical transfer

Answer 8

Only 50%

Question 9

What % of daughter cells obtain resistance via horizontal transfer

Answer 9

100%

Question 10

What type of mutation occurs with use of streptomycin

Answer 10

Ribosomal mutation

Question 11

What type of mutation occurs with use of quinolones

Answer 11

gyrase gene mutation

Question 12

What mutation occurs with use of rifampin

Answer 12

RNA polymerase gene mutation

Question 13

What is transduction

Answer 13

Use of bacteriophage to inject viral DNA into normal bacterial cell

Question 14

Transfer of antibiotic resistance via transduction is particularly important in strains of ___, where some phases carry plasmids that code for ___ and ___

Answer 14

S. Aureus
Code for: penicillinase and resistance to erythromycin, tetracycline, or chloramphenicol

Question 15

What is transformation

Answer 15

Incorporation of DNA that is free in the environment into bacteria

Question 16

Transformation is the molecular basis of ____ in ___ and ___

Answer 16

Penicillin resistance in Pneumoncocci and Neisseria

Question 17

Penicillin-resistant pneumococci produce ___

Answer 17

Altered penicillin binding proteins

Question 18

What is conjugation

Answer 18

Passage of genes from one cell to another by direct cell contact through sex pious

Question 19

Conjugation can result in resistance easily transferred to sensitive strains of ___ and ___

Answer 19

Shigella and enterobacteriaecea

Question 20

Genetic transfer by conjugation predominantly occurs in ___bacteria

Answer 20

Gram negative bacilli

Question 21

Conjugation can take place in the ___ between nonpathogenic and pathogenic microorganisms

Answer 21

Intestinal tract

Question 22

Bacteriostatic or bacteriocidal: no remarkable difference between bacteriostatic and bacteriocidal concentrations b

Answer 22

Bacteriocidal

Question 23

Bacteriostatic or bacteriocidal: bacteriostatic concentrations are much lower than bacteriocidal

Answer 23

Bacteriostatic

Question 24

What are the two mechanisms of killing for bacteriocidal agents

Answer 24

1. Concentration dependent killing
2. Time dependent killing

Question 25

What are some examples of antibiotics that do concentration dependent killing

Answer 25

Aminoglycosides and quinolones

Question 26

What are some examples of antibiotics that do time dependent killing

Answer 26

Beta-lactams and vancomycin

Question 27

What antibiotics are known to cause renal toxicity

Answer 27

Cephalosporins, vancomycin, aminoglycosides, sulfonamides, amphotericin B

Question 28

What antibiotics are known to cause hepatotocity

Answer 28

Tetracyclines, erythromycin, clindamycin, sulfonamides, amphotericin B

Question 29

What antibiotics are known to cause ototoxicity

Answer 29

Aminoglycosides, vancomycin, minocycline (vestibular only)

Question 30

What antibiotics are known to cause hemopoietic toxicity

Answer 30

Chloramphenicol and sulfonamides

Question 31

What antibiotics are photosensitive

Answer 31

Tetracycline, fluoroquinolones

Question 32

What is the postantibiotic effect

Answer 32

Persistent suppression of bacterial growth after limited exposure to antimicrobial agent

Question 33

What are some examples of antibiotics that have a post antibiotic effect

Answer 33

Aminoglycosides, quinolones

Question 34

___post antibiotic effects are longer than ___ due to postantibiotic ___effect

Answer 34

In-vivo, in-vitro, leukocyte

Question 35

What is synergism

Answer 35

When killing or inhibitory effects of two or more antimicrobials used together are significantly greater than expected from their effects when use individually

Question 36

What are two drugs that can inhibit one another’s cidal activity ex: pneumonoccoal meningitis

Answer 36

Penicillin and chloramphenicol- don’t use together

Question 37

Development of superinfections are most frequently observed with ___antibiotics

Answer 37

Broad spectrum

Question 38

What is empirical antimicrobial therapy

Answer 38

Antimicrobial agents used before the pathogen is known

Question 39

Extra-label use of specific antimicrobial drugs in ___animals is prohibited

Answer 39

Food producing animals

Question 40

What drugs are prohibited for use in food producing animals

Answer 40

Fluorquinolones, chloramphenicol, nitromidazoles, furazolidone, nitrofurazone, other nitrofurans, sulfonamides, vancomycin

Question 41

What sulfonamides is approved for use in food producing animals

Answer 41

Sulfadimethoxine

Question 42

___generation cephalopsorins are most used Extra-label in food producing animals for prevention of disease

Answer 42

3rd