Group 3: MEDI205 Human Health and Disease Processes by Bill Ashraf https://padlet.com/billash011/zl58yieu7f2d Basic Bacteriology - An Overview of Quorum sensing. en-us 2019-02-28 06:18:25 UTC 2025-04-28 23:59:32 UTC hello@padlet.com https://padlet.com/billash011/zl58yieu7f2d/wish/343567270 -10x more bacterial cells than human cells
- 100x more bacterial DNA than human DNA
 


- Activation of bacteria at a certain stage is called quorum sensing and is done through chemical communications of specific intra and inter species molecule release and detection respectively.
- Each bacteria releases a molecule that allows it to count its identical siblings
 


-Bacterial Cells secrete specific molecules and have a receptor looking for that chemical from other identical cells.

- Bacteria control pathogenicity with quorum sensing, which is their determination of when there are enough of them to cause a significant effect 


- They have a species-specific system/receptor and a interspecies molecule and receptor that they can use to communicate with themselves and other bacteria around them
 
- Bacteria can identify themselves from others

- Created anti-quorum sensing molecules to serve as antagonists at receptors
]]> 2019-03-20 22:37:23 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343567270 hanaa_cader https://padlet.com/billash011/zl58yieu7f2d/wish/343567899 2019-03-20 22:40:00 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343567899 How Bacteria "Talk" https://padlet.com/billash011/zl58yieu7f2d/wish/343568699  
  • Vibrio fischeri communication - that vs. when - grew to a significant size they turned on light simultaneously 
    • Low cell density = no light
    • High cell density = bioluminescence 
  • During Bassler's research, it was discovered that a bacterium called Vibrio fischeri living in the Hawaiian Bobtail Squid had a special property to make light when they grew to a certain cell number in a community.
    • Squid - dying culture of bacterium 
    • Pump attached to its circadian rhythm - during the day it pumps out the bacteria 
  • Bacterial Quoram Sensing - all bacteria have this
    • Signal producing protein
    • Signal receptor protein
    • Group behaviour genes 
  • Only successful when all bacteria respond - quoram sensing 
    • Intra-species communication
      • The left side is identical in every species of bacteria
    • The right side is slightly different
    • Exquisite species specific molecules ? Private secret conversation - intra-species communication
  • Multi-lingual bacteria
    • 2 systems in parallel: one species specific and one general (inter-species communication)
    • Bacteria are able to count how many of me and how many of you - what tasks to carry out depending on who is in the minority and who is in the majority of the species
    • A universal communication molecule for interspecies communication 
  • Antibiotics - next-gen? useful for combatting bacterial resistance?
    • Could you manipulate the universal communication molecule so that the bacteria can't talk or can't hear? (behaviour manipulation - can't release virulent?) 
    • Species/disease specific anti-quoram molecules 
  • Antagonists of the inter-species molecule too 
  • Multicellularity 
  • Bacteria can distinguish self from others 
  • Pro-quoram sensing molecules - make them work better, make the conversations better so they can carry out the tasks better 
]]> 2019-03-20 22:43:36 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343568699 https://padlet.com/billash011/zl58yieu7f2d/wish/343568965 2019-03-20 22:44:02 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343568965 https://padlet.com/billash011/zl58yieu7f2d/wish/343569092 - bacteria control pathogenicity with quorum sensing
- high specificity with quorum sensing
- bacteria are multilingual-> generic (inter-species) and specific languages(intra-species)
- universal communication
- anti-quorum sensing molecules-new therapeutics-> decreasing communication
- pro-quorum sensing molecules-> to increase communication 'conversation' between bacteria]]> 2019-03-20 22:44:42 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343569092 hanaa_cader https://padlet.com/billash011/zl58yieu7f2d/wish/343569194 2019-03-20 22:45:09 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343569194 Andre https://padlet.com/billash011/zl58yieu7f2d/wish/343569744 Overview:
- Bacteria consume nutrients from the environment to grow and subsequently divide, resulting in higher population density.

What is quorum sensing?
Quorum sensing is how bacteria communicate and are able to switch on genes to initiate pathogenicity.

Bacteria recognise each other through receptor and signal as well as recognise other species (inter-species) through a second receptor and signal. All bacteria use this.

Advantages of Research:
The reason we should invest and study quorum sensing is because it provides innovative ways to overcome the problem of bacterial resistance. I Another benefit of studying  quorum sensing is that it impedes inter and intra special communication. 

Po
 

]]> 2019-03-20 22:47:40 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343569744 https://padlet.com/billash011/zl58yieu7f2d/wish/343569963 2019-03-20 22:48:51 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343569963 Andre Too william_khoo168 https://padlet.com/billash011/zl58yieu7f2d/wish/343570131 2019-03-20 22:49:40 UTC https://padlet.com/billash011/zl58yieu7f2d/wish/343570131