Antimicrobial use Flashcards
Most common AB used on farm
- penicillin
- amoxicillin
- tetracyclines
- TMPS
- aminoglycosides
Bactericidal vs bacteriostatic
- bactericidal kills the bacteria
- bacteriostatic suppresses the growth
Penicillin: bactericidal or bacteriostatic?
- bactericidal
Penicillin: safe in pregnancy?
- yes
Penicillin: what does it penetrate in high doses?
- joints
- pleural cavity
- peritoneal cavity
- CNS
What causes the resistance of penicillin?
- beta-lactamase
How is penicillin eliminated?
- kidneys
Examples of aminopenicillins
- cloaxillin
- ampicillin
- amoxicillin
- clavulanic acid
Benefit of aminopenicillins over penicillin?
- work better against gram-negatives
Cephalosporins: bactericidal or bacteriostatic?
- bactericidal
What do cephalosporins work best against?
- gram positive aerobes
Do cephalosporins penetrate the placenta?
- yes
Why are cephalosporins not suitable for intra-mammary administration?
- low lipid solubility so will become trapped
Are cephalosporins safe in the pregnant animal?
- yes
How are cephalosporins eliminated?
- kidney
Examples of 1st gen cephalosporins
- cefalexin
- cefalonium
- cefazolin
Examples of 2nd gen cephalosporins
- not used
Examples of 3rd gen cephalosporins
- ceftiofur
- cefapirin
- cefoperazone
- cefovecin
Example of 4th gen cephalosporin
- cefquinome
What generation of cephalosporins is the most broad spec?
- 4th gen
Potentiated sulphonamides: bactericidal or bacteriostatic?
- bactericidal
What do potentiated sulphonamides work well against?
- gram positive aerobes
- gram negative aerobes
- some anaerobes but not clostridia
What are potentiated sulphonamides deactivated by?
- organic matter e.g. pus
Tissue penetration of potentiated sulphonamides
Good:
- CNS
- lung
- prostate
- skin
- mammary gland
- GIT
- urinary tract
- synovial fluid
- eye
Are potentiated sulphonamides safe in pregnant animals?
- yes
What is potentiated sulphonamides metabolised by?
- liver
What are potentiated sulphonamides eliminated by?
- kidneys
Example of potentiated sulphonamide
- TMPS
Tetracyclines: bactericidal or bacteriostatic?
- bacteriostatic
What do tetracyclines work well against?
- gram negative
- gram positive
- some action against anaerobes
What specific bacteria do tetracyclines work well against?
- chlamydia
- mycoplasma
- bordetella
- spirochaetes
What can tetracyclines penetrate?
- most bodily tissues and fluids
Examples of tetracyclines
- oxytetracycline
- doxycycline
What trimester should you avoid the use of tetracyclines?
- 1st
Aminoglycosides: bactericidal or bacteriostatic?
- bactericidal
What do aminoglycosides work against?
- gram negative aerobes
Do aminoglycosides have good penetration?
- no
What are aminoglycosides deactivated by?
- pus
Are aminoglycosides safe in pregnant animals?
- yes
What other class of antibiotic can aminoglycosides be combined with?
- penicillin
Examples of aminoglycosides
- gentamicin
- streptomycin
- neomycin
What aminoglycosides is banned in food-producing animals?
- gentamycin
Macrolides: bacteriostatic or bactericidal?
- bacteriostatic
What do macrolides work against?
- gram positive
- gram negative
Do macrolides have good or poor penetration?
- good
Where are macrolides excreted?
- bile
What macrolide can not be used in lactating animals?
- tulathromycin
Examples of macrolides
- erythromycin
- tulathromycin
- tilmicosin
What category of antibiotics should be used in the first instance?
- cat D
When can category C antibiotics be considered?
- when cat D is not clinically effective
When can category B antibiotics be considered?
- when there is no appropriate cat C or D
When can category A antibiotics be considered?
- never
– not authorised in food-producing animals
Examples of cat D AB
- amoxicillin
- oxytet
- penicillin
- cloaxicillin
- TMPS
Examples of cat C AB
- streptomycin
- amoxiclav
- cefalexin
- florefenicol
- tulathromycin
Examples of cat B AB
- cephalosporin 3rd & 4th gen
- polymixins
- quinolones
What AB would you give: BRD infection
- oxytet
What AB would you give: bacterial meningitis
- TMPS
What AB would you give:
Pig with diamond shaped skin lesions on its back?
- penicillin
What is the likely diagnosis of a pig with diamond shaped skin lesions on its back?
- erysipelas
What AB would you give:
Sheep with head tilt, circling with a flaccid left ear?
- penicillin
What AB would you give:
Large swelling of carpus in a calf?
- penicillin
What AB would you give: A cow with a stiff gait, elevated tail head and muscle tremors in the hindlimb?
- penicillin
What AB would you give: Recumbent pyrexic calf with no suckle reflex?
- TMPS
What AB would you give: 3cm red raw lesion in the interdigital space of the hindclaw?
- oxytet
What AB would you give: Young heifers at grass with corneal opaqueness, blepharospasm and photospasm?
- oxytet
What AB would you give: Ewe that is depressed with harsh lung sounds?
- oxytet
What is the likely diagnosis for a cow with a stiff gait, elevated tail head and muscle tremors in the hindlimb?
- tetanus
