300 likes | 1.18k Views
Quorum Sensing. By Sachi Lagwankar. What is QS?. process of bacterial cells “talking” to each other in order to be informed of the population density in its vicinity Bacteria can only act on the host cell when the impact of the process is at its maximum Mutants (change signaling patterns)
E N D
Quorum Sensing By Sachi Lagwankar
What is QS? • process of bacterial cells “talking” to each other in order to be informed of the population density in its vicinity • Bacteria can only act on the host cell when the impact of the process is at its maximum • Mutants (change signaling patterns) use QS in order to attack. • used commonly when starting infections in organisms.
Autoinducers Gram positive bacteria Gram negative bacteria Pseudomonas quinolone signal (PQS; 2-heptyl-3-hydroxy-4-quinolone) Oligopeptide signal
What are Autoinducers? Chemical molecular signals gram negative bacteria: acylatedhomoserine lactones (AHL) Gram positive bacteria: oligo-peptides
Importance only way mutants know how to communicate scientists are trying to find a way to inhibit this so that mutants don't take over host cells.
Biofilm sticky layer of polymers that microorganisms secrete and stick to one another on all surfaces Controlled by AI 2 Common in people, though they can cause illness
Antibiotics Multidrug-Resistant Tuberculosis (MDR TB) is resistant to the two most commonly used antibiotics for TB- isoniazid (INH) and rifampin (RIF). This means that people who get TB are unable to be cured using these antimicrobials. “tame” bacteria, and not to kill them
Option 1 Paul Williams: generate a drug that can search and take out bacteria and that will prevent them from doing damage to the host cell.
Option 2 Geoff Watts: stop bacteria from sending signals, eliminate infections
Option 3 Peter Greenberg: encourage mutants to dominate fatal wounds and they do better and do not use quorum sensing and are less virulent
Option 4 Steve Diggle: experiment- add mutants to the potential fatal wounds already infected with the virulent bacteria, those wounds actually did better.
Option 5 Alan Smyth: a natural quorum sensing inhibitor is to use extracts of plants like garlic extract
Design Goal the immune system take over the virus before it attacks the host cell and infects it. when mutants send signal, cell makes protein to be released out of cell confuse the mutant into thinking there are more of it. when the mutant attacks, the human cell will use its immune system to kill the mutant.
Ethics idea of how quorum sensing can be used to prevent illness in humans. this is designed to help humans and prevent them from getting illnesses.
Sources • http://www.bbc.co.uk/programmes/p01bhlvr • http://rstb.royalsocietypublishing.org/content/362/1483/1241.full • http://downloads.bbc.co.uk/podcasts/worldservice/discovery/discovery_20130708-2000a.mp3 • http://www.ncbi.nlm.nih.gov/pubmed/23142623 • https://www.youtube.com/watch?v=2R4XHRufoWI • http://jb.asm.org/content/187/13/4372 • http://en.wikipedia.org/wiki/Autoinducer • http://www.perspectivesinmedicine.net/content/2/11/a012427.full • http://www.ncbi.nlm.nih.gov/pubmed/11544353 • https://www.bio.cmu.edu/courses/03441/TermPapers/99TermPapers/Quorum/table.htm • http://www.ncbi.nlm.nih.gov/pubmed/11018124 • http://www.niaid.nih.gov/topics/tuberculosis/understanding/whatistb/pages/tbdefinitions.aspx • http://mpkb.org/home/pathogenesis/microbiota/biofilm