Antibiotics in FA

Question 1

Are sulfonamides time-dependent or concentration-dependent?

Answer 1

Time-dependent

Question 2

What is the spectrum for sulfonamides?

Answer 2

G+, G+, and some protozoa

Question 3

Which organisms are resistant to sulfonamides?

Answer 3

Pseudomonas
Bacteriodes
Enterococcus

Question 4

What is the MOA of sulfonamides?

Answer 4

• mimic PABA precursor, blocking production of the active form of folic acid
• potentiated sulfas inhibit dihydrofolate reductase

Question 5

Are sulfonamides cidal or static?

Answer 5

Bacteriostatic

Potentiated sulfas are bacteriocidal

Question 6

What are the restrictions for sulfonamides?

Answer 6

Only sulfadimethoxine in dairy cows

Question 7

Are beta-lactams time-dependent or concentration-dependent?

Answer 7

Time-dependent

Question 8

Are beta-lactams cidal or static?

Answer 8

Bacteriocidal

Question 9

What is the MOA of beta-lactams?

Answer 9

bind to penicillin-binding proteins

• PBP1 causes cell lysis
• PBP2 causes misshapen cell walls leading to rupture

Question 10

What is the spectrum for beta-lactams?

Answer 10

Natural penicillins - G+, anaerobes, select G-, and spirochetes
Aminopenicillins - G-, some E. coli and Salmonella
Cephalosporins - similar to penicillins, with more G- as generation increases

Question 11

What are the restrictions for beta-lactams?

Answer 11

• Can only use 3rd generation cephalosporins

- ELDU is permitted

Question 12

Are tetracyclines cidal or static?

Answer 12

Bacteriostatic

Question 13

What is the MOA for tetracyclines?

Answer 13

• binds to 30s ribosome

- prevents protein synthesis

Question 14

Are aminoglycosides cidal or static?

Answer 14

bacteriocidal

Question 15

Are aminoglycosides time-dependent or concentration-dependent?

Answer 15

concentration-dependent

Question 16

What is the spectrum of aminoglcosides?

Answer 16

primarily aerobic, also G-

Question 17

What is the MOA of aminoglycosides?

Answer 17

• binds to 30s ribosome

- prevent protein synthesis

Question 18

What are the restrictions for aminoglycosides?

Answer 18

• Zero-tolerance drugs

- should only be used in neonate pigs

Question 19

Is florfenicol time-dependent or concentration-dependent?

Answer 19

Time-dependent

Question 20

Is florfenicol cidal or static?

Answer 20

Bacteriostatic

Question 21

What is the spectrum of florfenicol?

Answer 21

Broad G-, some G+

Question 22

What is the MOA of florfenicol?

Answer 22

• inhibits protein synthesis

- blocks peptidyltransferase activity at the 50s ribosome

Question 23

What is the spectrum for macrolides?

Answer 23

G+ and select G-

Azalides against Mycoplasma

Question 24

What is the MOA of macrolides?

Answer 24

inhibits protein synthesis by binding to 50s ribosome

Question 25

Are macrolides time-dependent or concentration-dependent?

Answer 25

time-dependent

Question 26

Are macrolides cidal or static?

Answer 26

Bacteriostatic

Question 27

What are the restrictions for lincosamides?

Answer 27

• use in swine only

- avoid in foregut and hind gut fermentors

Question 28

Are fluoroquinolones time-dependent or concentration-dependent?

Answer 28

concentration-dependent

Question 29

Are fluoroquinolones cidal or static?

Answer 29

Bacteriocidal

Question 30

What is the spectrum for fluoroquinolones?

Answer 30

• most G- bacteria

- some G+

Question 31

What is the MOA of fluoroquinolones?

Answer 31

inhibit bacterial DNA replication and transcription by binding A subunit of DNA gyrase

Question 32

What are the restrictions for fluoroquinolones?

Answer 32

ELDU is forbidden