Antibiotics In the Food Supply

Question 1

What are the 4 antibiotic categories?

Answer 1

1) very high importance
2) high importance
3) medium importance
4) low importance

Question 2

Does banning antibiotic work?

Answer 2

Yes. After bans you see a leveling off, and even a decrease of the AMR in the community.

Question 3

What is synercid?

Answer 3

Synercid (category I) is a semisynthetic antibiotic that is approved to treat MRSA in humans

Question 4

virginiamycin acetyltransferases confers resistance to ______________ also confers resistance to _____________

Answer 4

virginiamycin (category IV)

Synercid (category I)

Question 5

Manure resistome leads to ____________ and then to _____________

Answer 5

soil resistome and crop resistome

Question 6

Antibiotics used in food-producing animals help select for the presence of antibiotic _______________and antibiotic ______________

Answer 6

resistance genes (ARGs) 
resistant bacteria (ARBs)

Question 7

What are the different mode of action for antibiotics? (4)

Answer 7

• Inhibit cell wall synthesis
• Inhibit protein synthesis
• Inhibit DNA synthesis
• Inhibit folic acid synthesis

Question 8

Antibiotics are used for what 4 things:

Answer 8

1) Disease treatment
2) Disease prevention
3) Growth promotion
4) Human

Question 9

What is AMR?

Answer 9

AMR describes the decreased susceptibility of a multitude of microbes to a broad spectrum of single or multitude antibiotics

Question 10

Antibiotics can be classified into 2 categories, what are they?

Answer 10

Bactericidal and bacteriostatic

Question 11

Talk to me about bactericidal antibiotics, give me a few characteristics…

Answer 11

• Bactericidal antibiotics kill bacterial cells
• They target key cell structures (biosynthesis of the cell wall, or DNA)
• B-lactam antibiotics family, aminoglycosides, quinolones

Question 12

Talk to me about bacteriostatic antibiotics, give me a few characteristics…

Answer 12

• Inhibit further growth
• Target protein synthesis
• Macrolides, tetracyclines, sulfonamides, telithromycin

Question 13

What are the 2 schools of thought for AMR in the food chain?

Answer 13

1) The Food Chain Propagates AMR Infections in Humans:
- AMR foodborne pathogens are common
- AMR in commensal bacteria on food items are is also very common
- The AMR genepool in food must therefore be very high
- It is very likely that humans are being continuously exposed to AMR genes through the food chain

2) The Food chain does not propagate AMR infection in humans:
- The actual number of pathogens in foods is very small
- The actual number of AMR pathogens in food is very, very small
- Do any of these genes actually move to organisms in the GI tract?

Question 14

AMR due to genetic changes can be transmitted by _______ or _________ gene transmission

Answer 14

vertical or horizontal

Question 15

Horizontal Gene Transfer (HGT) mediates the spread of AMR to bacterial cells by mobile genetic elements like : (name 3)

Answer 15

• plasmids
• transposons
• integrons

Question 16

Horizontal gene transfer can occur via ___________, _________ & _____________

Answer 16

conjugation, transformation, and transduction

Question 17

What are the mecanisms used by AMR bacteria? (5)

Answer 17

1) Export
2) Destruction
3) Modification
4) Altered receptors
5) Membrane composition

Question 18

What is another name for Colistin:

Answer 18

Polymyxin E

Question 19

What is Colistin?

Answer 19

is a very old antibiotic that was not used in humans due to kidney toxicity. However, due to the spread of AMR use became more prevalent in the 1990’s

Question 20

TRUE OR FALSE: AMR can be detected from the whole genome sequences of bacteria

Answer 20

TRUE

Question 21

What does the disk diffusion test measure?

Answer 21

the sensitivity of a bacteria to a specific antibiotic

Question 22

Explain the disk diffusion test :

Answer 22

• It usesantibiotic discswhich are placed on an agar plates containing a lawn of bacteria, and the plate is left to incubate
• If an antibiotic stops the growth of the bacteria, this is called the zone of inhibition
• The size of this zone depends on many factors, one being how effective the antibiotic is at stopping the growth of the bacterium, another is the rate diffusion of the antibiotic within the agar medium and varies based on the molecular configuration of the antibiotic
• Once the zone diameter is measured it must be compared to a database of zone standards to determine if the bacterium being studied is susceptible, moderately susceptible or resistant to the antibiotic in question

Question 23

What does MIC stands for:

Answer 23

minimal inhibitory concentration (lowest concentration of a drug at which no visible growth occurs)

Question 24

What are Sensititre MIC plates?

Answer 24

• 96-well plates that contain lyophilized antibiotics configured to determine the MIC to a variety of antibiotics
• Dilutions of bacteria with a usable carbon source are inoculated into each well of the plate
• The plates can be inspected visually or with a plate-reader to determine the MIC for each antibiotic