EFSA: Risk communication

http://www.efsa.europa.eu/en/efsawhat/riskcommunication.htm


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EFSA: Videos

http://www.efsa.europa.eu/en/news/videos.htm


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Updates of Mind Maps

Thanks to the students who reminded me that I have not uploaded some of the lecture Mind Maps. I have checked and upload the missing ones. If you find that I still miss some, please let me know.

HS Kwan

Review session questions

Question: why is the most heat-sensitive enzyme inactivated determining the growth and servival of the microorganism.

Answer: Refers only to essential enzymes. Inactivating the most hear-sensitive essential enzyme would stop the growth and may affect the servival of the cells.

 Question: How does Prp changed into Prp-sc  and cause mad cow disease?

Answer: Prp may change into Prp-sc by mutation. OR human acquired Prp-sc from food source. Prp-sc can recruit normal Prp and change its form to Prp-sc. Prp-sc aggregates to form rod-shaped polymers that can block the nutrient and energy supply of brain cells and cause mad-cow disease.

Review Session 20130429 Question from students and Answers 5

Question:  

•  Any more information on DAEC?

Not much is known about this bacteria

•  Fungal toxin included in examination?

 Not covered in lecture--> not included in examination

• Food preservation covered in examination?

No direct coverage in lecture. But still need to note things like Nitrate effect on Redox--> effect on anaerobic bacteria growth 

Review Session 20130429 Question from students and Answers 4

Question:

Are all Clostridium spp unable to ferment sugar?

Consult: Microbe Wiki http://microbewiki.kenyon.edu/index.php/Clostridium_perfringens

C. perfringens has all the glycolytic genes and should be able to ferment sugar.

C. botulinum--no report on sugar fermentation

Review Session 20130429 Question from students and Answers 3

Question: Shigella

• Does it infect other primates?

Yes.  

• Pathogenicity picture explain more?

Note the picture:

• Endocytosis- Shigella gets into enterocyte
• Enclosed by vacuole
• Break out from vacuole
• Propagate in cell
• Cell secretes cytokines
• Cytokines attract PMN
• PMN opens up tight junctions between enterocytes
• Damage enterocyte layer
• Shiga toxin from Shigella gets into blood
• Damage blood vessels
• Blood diarrhea and systemic symptoms

Not in exact sequence, e.g., shiga toxin can be produced any time