Antimicrobial Residues

Question 1

Which antibacterials are tested for in milk and why?

Answer 1

Penicillins

• G+ bacteria (lactobacillus, lactobacilli, strep) necessary for cheese production (lactose->acids to curdle cheese)
• penicillin hypersenstivity in humans

Question 2

What is the name of the test for penicillins?

Answer 2

Delvotest

Question 3

What barrier may affect withdrawal periods in dairy cattle?

Answer 3

Blood milk barrier. If drug cant cross -> 0 day withdrawal

Question 4

How does the body affect drug residues?

Answer 4

• distribution (barriers, CNS, milk)
• activation and metabolism (liver)
• clearance (enterohepatic circulation, bladder/kidneys)

Question 5

Where should drug withdrawals and portocols be looked up?

Answer 5

• NOAH
• VMD
• Drug cascade

Question 6

Who sets the regulations for drug withdrawal?

Answer 6

VMD

Question 7

What is the standard withdrawal for milk and meat?

Answer 7

• 7d milk
• 28d meat
  > double for organic animals

Question 8

Which drug should not be used in egg producing birds?

Answer 8

Enrofloxacin (Baytril)

- 14d withdrawal

Question 9

Which drug may cause aplastic anaemia? Which drug can be used instead?

Answer 9

• chloramphenicol
  > especially after oral consumption
  > very lipophilic
• use florphenicol (new version)

Question 10

Which 2 drugs should never be used in food producing animals?

Answer 10

• Metronidazole
• Phenylbutazone
  > carcinogenic

Question 11

Who’s responsibility are residues?

Answer 11

Farmer or owner

Question 12

What is the main residue checked for in milk?

Answer 12

B lactams (penicillins)

Question 13

Where are residues checked for in meat?

Answer 13

• Kidney test in abbattoir in case of suspicion or targetted surveillance

Question 14

What surveillance results were found in “residues of vet medicine in food 2012”?

Answer 14

• bees and fish ±10% positive samples
• Bute 5% horses
• Zeronol (oestrogen derivative): fungal contamination of feed
• Thiuracil (T4 moderator): brassica in feed

Question 15

What are the 2 WHO criteria for importance of Abx to human medicine?

Answer 15

1. Antimicrobial agent which is the sole, or one of limited therapy, to treat serious human disease
2. Antimicrobial agent used to treat diseases caused by either a) organisms that may be transmitted to humans from non-human sources or b) human disease caused by rgnaisms that may aquire resistnece genes from non-human sources

Question 16

Define critically, highly and important to human medicine for WHO list of Abx?

Answer 16

• Critically important meet both criterion 1 and 2
• Highly important meet either 1 or 2
• Important do not meet criteria 1 or 2

Question 17

How many groups of Abx are classified in each of the WHO groups?

Answer 17

Critical: 15
Highly: 13
Important: 4