Macrolides

Question 1

What is the MOA for the tetracyclines?

Answer 1

30S inhibitors

Question 2

Is the MOA of the tetracyclines reversible or irreversible? Bacteriostatic or bactericidal?

Answer 2

Reversible –> Bacteriostatic

Question 3

Which 4 organisms are sensitive to the Tetracyclines?

Answer 3

1. Brucella
2. Rickettsia
3. Spirochetes
4. Chlamydia

Question 4

Which is energy-dependent, the uptake of Tetracyclines in gram (+) bacteria or gram (-) bacteria?

Answer 4

Gram (-)

Question 5

In which environments is gram (-) uptake of Tetracyclines poor?

Answer 5

1. Anaerobic conditions

2. Low pH

Question 6

____ is a neuroprotective agent that inhibits apoptosis in neurons.

Answer 6

Minocycline

Question 7

____ is a good choice in the presence of a neuropathy because it is NOT eliminated via the kidneys.

Answer 7

Doxycycline

Question 8

Tetracyclines are chelated by what?

Answer 8

1. Mg+2

2. Ca+2

Question 9

Because Tetracyclines are chelated by Mg+2 and Ca+2, they are poorly absorbed in the presence of what?

Answer 9

Milk

Question 10

Tetracyclines also cause what in the fetus, neonate, and juvenile?

Answer 10

Tetracyclines are deposited into bone and teeth and cause YELLOW DISCOLORATION

Question 11

Which Tetracycline does NOT cause the yellow bone/teeth discoloration?

Answer 11

Minocycline

Question 12

List the 5 other toxicities associated with the Tetracyclines.

Answer 12

1. Nephrotoxicity
2. GI effects
3. Esophageal stricture
4. Injection site irritant
5. Photosensitivity

Question 13

Which Tetracyclines are NOT associated with nephrotoxicity?

Answer 13

1. Doxycycline

2. Minocycline

Question 14

Which Tetracycline causes esophageal stricture in the cat?

Answer 14

Doxycycline

Question 15

What are Tetracyclines use vs. in foals?

Answer 15

Contracted tendons

Question 16

Which Tetracycline is commonly use vs. BRD (bovine respiratory disease)?

Answer 16

Hexasol

Oxytetracycline + Flunixin

Question 17

What is the MOA of the macrolides?

Answer 17

Bind to the 50S ribosome to interrupt tRNA binding and peptide chain elongation.

Question 18

Is the MOA of macrolides reversible or irreversible? Bacteriostatic or bactericidal?

Answer 18

Reversible –> Bacteriostatic

Question 19

What is the spectrum of the Macrolides?

Answer 19

1. ALL gram +

2. Gram (-) anaerobes

Question 20

Most Macrolides are NOT effective against which bacterial group?

Answer 20

Enterobacteriaceae

Question 21

Which Tetracycline is the BEST versus Mycoplasma?

Answer 21

Tulathromycin

Question 22

Which of the following is effective and which is ineffective against Mycoplasma: Erythromycin, Tylosin?

Answer 22

Erythromycin is NOT effective

Tylosin is usually effective

Question 23

How do Macrolides primarily gain resistance?

Answer 23

Methylation of the ribosome

Question 24

The methylation associated with Macrolide resistance confers cross-resistance with which two antimicrobial classes?

Answer 24

1. Lincosamides

2. Streptogramins

Question 25

Which 2 Macrolides cause sterile abscesses?

Answer 25

1. Tylosin

2. Erythromycin

Question 26

Which Tetracycline is cardiotoxic in the human?

Answer 26

Tilmicosin

Question 27

Which Macrolide prevents tear staining due to epiphora?

Answer 27

Tylosin

Question 28

In which species should Tylosin NOT be used?

Answer 28

Equine

Question 29

What are the top 3 uses of Tulathromycin?

Answer 29

Bovine and swine (1) respiratory disease, (2) foot rot, (3) pink eye.

Question 30

What is the main indication for the use of Clarithromycin?

Answer 30

Vs. Rhodococcus in the horse (+ rifampin)

Question 31

What is Tylosin used vs. in poultry?

Answer 31

Mycoplasma

Question 32

What is Tylosin used vs. in dogs?

Answer 32

1. Epiphora

2. IBD

Question 33

What is Tylosin used vs. in swine?

Answer 33

1. Mycoplasma

2. Brachyspira

Question 34

What is the spectrum of the Macrolides?

Answer 34

1. Gram (+)

2. Gram (-) anaerobes