Antibiotics in Food Animals Flashcards Preview

RUSVM LAM II > Antibiotics in Food Animals > Flashcards

Flashcards in Antibiotics in Food Animals Deck (66):
1

Sulfonamides are time/concentration dependent 

time dependent

2

sulfonamides are effective against ______

gram (+), gram (-) and some protozoa 

3

organisms known to be resistant to sulfonamides

Pseudomonas, Bacteroides, and Enterococcus 

4

T/F sulfonamides are bacteriostatic except potentiated sulfas which are bactericidal

True

additives increase strenght/effectiveness (i.e TMS)

5

where are sulfonamides distributed 

wide distribution 

joints via synovial fluid, CNS, prostate, urine etc - esp potentiated 

6

T/F sulfonamides can be given to dairy cattle

False! 

only sulfadimethoxine 

7

T/F potentiated sulfas are used off label in calves and pigs 

true

8

beta-lactams are time/concentration dependent 

time dependent

9

beta lactams are bactericidal/static

bactericidal 

10

what are some examples of beta lactams

penicillins and cephalosporins 

11

what is the action of beta-lactams 

bind penicillin-binding proteins

PBP-1 (panems) cause immediate cell lysis 

12

T/F beta-lactams can be combines with a bacteristatic to increase efficacy 

False!

Bacteria has to have 1 replication cycle for the beta-lactams to be cidal, combining with -statics make them useless 

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13

T/F penicillins generally need more time than cephalosporins

 

False

cephalosporins generally need more time than penicillins 

14

______ require more exposure than ______

gram (-) require more exposure than gram (+)

15

how to organisms become resistant/avoid beta-lactams

production of beta-lactamase or alter PBP to prevent binding

3rd Generation Cephalosporins are usually unaffected by beta-lactamases

16

what is the spectrum of natural penecillins

gram (+), anaerobes, select gram (-): Listeria; and spirochetes

17

spectrum of aminopenicillins 

more gram (-), some stains of E. coli and Salmonella

18

how does the spectrum of Cephalosporins differ from penicillins 

similar but more gram (-) coverage as generation increases

19

T/F beta lactams have poor intracellular activity

True 

20

what are some indications for tetracyclines

Anaplasma

wooden tongue (Actinobacillus)

lumpy jaw (Actinomycosis)

21

tetracyclines are ______ dependent

AUC/MIC dependent

AUC has to be about 120x MIC to be effective 

22

what is the mechanism of tetracyclines

bind to 30s ribosomes, prevents protein synthesis

minimal affinity for mammalian ribosomes 

23

routes of administration of tetracyclines 

IV, IM, SQ, PO

poor ora absorption - except doxy

24

distribution of tetracycline 

lipophillic (intracellular) 

wide distribution (most tissues)

accumulate intracellularly, even leukocytes - posible anti-inflammatory effects 

25

how are tetracycline eliminated

60% via glomerular filtration 

40% through feces 

26

there is increasing concern about ________ with tetracyclines 

RESISTANCE!

27

examples of aminoglycosides

neomycin and gentamicin 

28

aminoglycocides are bacteristatic/cidal and are concentration/time dependent

bactericidal

concentration dependent 

29

aminoglycoside spectrum 

primarily aerobic

gram (-)

30

T/F aminoglycosides and tetracyclines are both lipid soluble and act on the 30s ribosome 

False!

aminoglycosides are highly water soluble and poorly lipid soluble 

31

what is meant by post antibiotic effect see with aminoglycocides 

accumulate in lysosomes and mitochondria 

PAE - having effect in the desired area but no longer found in plasma at significant concentrations 

32

why is there a long withdrawel period with aminoglycosides 

chemically attracted to phospholipids 

33

what toxicities are seen with aminoglycosides

nephrotoxic

ototoxic 

these tissues have more phosphatidylinositol in their membranes than other body tissues (mainly gentamicin), this is also there is a concern about residue (kidney) 

34

T/F gentamicin is recommended for use in cattle

FALSE!

not labeled for cattle! Aminoglycosides are a zero tolerance drugs!

35

what is the current withdrawel time for gentamicin in cattle 

18 months per single injection for meat 

5 days for milk following IV, IM or SQ 

36

practictioners are stongly urged to refrain from using aminoglycosides in food animals except ______

neonatal pigs 

37

what is thought to prevent bacterial inactivation of Florfenicol

fluorine at the 3' carbon position

38

T/F florenfenicol is always bacteriostatic by nature

False

blocks 50s ribsome, time dependent = static 

at peak concentrations = cidal; always cidal for Fusabacterium necroforum 

 

 

39

spectrum for florfenicol 

broad gram (-) → espcially BRD pathogens

some gram (+)

40

indications for florfenicol

BRD

keratoconjunctivitis

bovine interdigital phlegmon (aka foot rot) 

41

distribution of florfenicol 

lipid soluble, wide tissue distribution 

concentrates in tear film (pinkeye) 

CNS - H. somni (above MIC for 20hrs) 

diseased lung

high urine concentrates

mammary (mastitis) 

42

is extra-label use of florfenicol permitted 

yes

prolonged withdrawal for different than labeled production class

(ex. IM dose in lactating dairy cow has 60 day withdrawal)

43

examples of macrolides

Azalides = Azithromycin, Tulathromycin, Gamithromycin, and Tildipirosin

44

spectrum of macrolides

fairly broad

gram (+)

select gram (-) → BRD pathogens 

45

Azalides have activity against ________

mycoplasma

46

MOA of macrolides 

inhibit protein synthesis by binding at 50s ribosomal subunit

47

why is there a possible antagonistic effect between macrolides and florfenicol

binding sites are close to each other 

48

T/F tissue concentrations of macrolides are higher than serum concentrations

True

concentrate in cells more acidic than plasma, accumulate in lysosomes of leukocytes

49

macrolides have good absorption through ______

the gut 

50

lincosamides are primarily used in ______

swine

avoid in hindgut and foregut fermenters- clostridial overgrowth

51

MOA of lincosamides

inhibit protein synthesis by binding 50s ribosome 

52

lincosamides have essentially the same spectrum of activity as _____

macrolides

53

lincosamides are used to treat

Mycoplasma pneumonia

bacterial arthritis caused by Strep, Erysipelothrix, or Mycoplasma

54

what common adverse effect is seen with lincosamides

swelling of the anus 

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55

what is a highly restricted class of antibiotic that ELDU is strictly forbidden with

fluoroguinolones

56

enrofloxacin is approved for use in _______

cattle 

swine

57

fluoroquinolones are bacteriostatic/cidal and time/concentration dependent 

bactericidal

concentration dependent 

58

spectrum of fluoroquinolones

most gram (-)

gram (+) variable susceptibilty - have higher MIC than gram (-)

59

MOA of fluoroguinolones

Inhibit bacterial DNA replication & transcription by binding the A subunit of DNA gyrase

60

like beta-lactams, fluoroquinolones should not be paired with a bacteriostatic anitbiotic

False 

kill bacteria whether they are replicating or not 

61

distribution of fluoroquinolones 

wide

lipid soluble 

 

62

what is the concern with use of fluoroquinolones in food animals

concern about transfer of resistance from animals to people 

63

what are the bacteria of concern with fluoroquinolones 

campylobacter 

salmonella typhimurium type DT-104 

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