Transcript File - Science Research

Analysis of Common Food Remedies as Quorum Sensing Inhibitors
Jalin Cunningham
Introduction
•The overuse of antibacterial products has led to a cycle of antibiotic
resistance, in which product infused with antibiotics kills off the
majority of bacteria present, but leaves behind a small amount of
bacteria that are usually the most potent forms.
Methodology
Discussion
•The results of this study did not support the hypothesis that the
majority of the extracts would inhibit bacterial growth in some way.
•Quorum sensing(QS) is the process of communication between
individual bacterium that can be used to combat antibiotic resistance.
•This could possibly provide some insight into the “mind-overmatter” debate when it comes to treating illnesses with household
remedies.
•When QS stops in a colony of bacteria, individual cells are no longer
able to communicate with each other, and therefore become isolated and
die.
Conclusion
•Many natural substances, like the antioxidants found in different fruits,
vegetables, spices and herbs can inhibit QS.
•The hypothesis for this study was refuted.
Review of Literature
•In studies such as Screening of traditional Chinese medicinal plants for
quorum sensing inhibitors activity (Koh, Tham, 2011) and Dietary
phytochemicals as quorum sensing inhibitors (Vattem, et al., 2006),
plant, spice, and fruit extracts were tested for their anti-QS potential.
Trial #
1
honey
garlic
•Past studies in this field have been, for the most part, successful.
orange juice
2
3
4
5
Vattem, et.al., 2006
•The graph above shows that all 8 of the
extracts tested in Vattem’s study were
effective in inhibiting QS in Escherichia
coli and Pseudomonas aeruginosa.
•Similarly, the picture on the left shows the
zones of inhibition in Koh’s study for the
10 species of medicinal plants.
Objective
Koh, Tham, 2011
•The purpose of this study was to determine if eight different natural
extracts would be effective in inhibiting QS in three different strains of
bacteria.
•It was hypothesized that most, if not all, of the extracts would extracts
would exhibit QS inhibition in some form.
Key Terms
Phytochemical: An antioxidant, or a molecule that inhibits the oxidation
of others.
Pathogen: A bacterium, virus, or other microorganism that can cause
disease.
Inoculation: The act of implanting microorganisms into a culture
medium.
Extracts
cinnamon
6
cinnamon
honey
garlic
orange juice
cinnamon
honey
garlic
orange juice
cinnamon
honey
garlic
orange juice
anise seed
mustard seed
cumin
cayenne pepper
anise seed
mustard seed
cumin
cayenne pepper
Procedure
Stirred into a 1:1 mixture of
cinnamon and olive oil, then
boiled and left to cool
Stirred into a 1:1 mixture of
honey and tap water, then
boiled and left to cool
Stirred into a 1:4 mixture of
garlic and tap water until
dissolved
Stirred into a 1:1 mixture of
orange juice and tap water
Same as trial 1
Solvents were stirred into a 1:1
mixture of acetone and water so
that the solute to solvent
volume ratio was 1:6, then
vacuum filtrated with a coffee
filter and left to evaporate
Same as trial 3
•In order for this study’s results to become more valid, it should
be repeated in a sterile laboratory setting to confirm that the
results were not that of human error.
• Extracts were chosen
based on their
widespread consumption
during times of illness or
anecdotal evidence of
their antiseptic
properties.
•Zones of inhibition were
measured with a
centimeter ruler after a
growth period of 24
hours.
•Hopefully with more research and development in the field of
QS, more pathways to alternative treatment of bacterial
infections will be found and the threat of antibiotic resistance
will ideally be eliminated.
References
Adonozio, A., et al. "Anti-quorum sensing activity of medicinal plants in southern Florida."
Journal of Ethnopharmacology 105 (2006): 427-35. Print.
Same as trial 3
Koh, Khee Hoon, and Foong-Yee Tham. "Screening of traditional Chinese medicinal plants
for quorum-sensing inhibitors activity."
Same as trial 3
Results
•Out of the eight extracts tested in total, only cinnamon showed a zone of
inhibition in S. aureus after the 24 hour growth period.
•A clear halo measuring 1.5 centimeters in diameter was found for that particular
section of the plate, while for all other extracts and bacterial species, no
interruption of growth was found.
An example
of a plate
after bacterial
growth had
completed
and extract
inoculation.
•In the future, one could:
• extend the species and bacteria
• conduct a follow-up study with human subjects to
test whether or not household remedies for illnesses
actually have a distinct scientific effect on us.
The results of Trial
3 on S. aureus.
Again, zones can be
found for
cinnamon, this time
on the bottom left.
Colors were
inverted to make
viewing easier for
the reader.
Journal of Microbiology, Immunology, and Infection (2009): 144-48. Print. Nantang, Ni, et
al. "Identification of boronic acids as antagonists of bacterial quorum sensing in Vibrio
harveyi." Biochemical and Biophysical Research Communications 369.2 (2008): n. pag.
Print.
Rasmussen, Thomas B., and Michael Givskov. "Quorum-sensing inhibitors as antipathogenic drugs." International Journal of Medical Microbiology 296 (2006): 149-61.
Print.
Taganna, Jomar, et al. "Tannin-rich fraction from Terminalia catappa inhibits quorum
sensing (QS) in Chromobacterium violaceum and the QS-controlled biofilm maturation and
LasA staphyloytic activity in Pseudomonas aeruginosa." Journal of Ethnopharmacology
134 (2011): 865-71. Print.
Truchado, P., et al. "Quorum sensing inhibitory and antimicrobial activities of honeys and
the relationship with individual phenolics." Food Chemistry 115 (2008): 1337-44. Print.
Truchado, Pilar, et al. "Food phytochemicals act as Quorum Sensing inhibitors reducing
production and/or degrading of Yersinia enterocolitica and Erwinia carotova." Food
Control (2012): 78-85. Print.
Vattem, D., et al. "Dietary phytochemicals as quorum sensing inhibitors." Filoterapia
(2007): 302-10. Print.
Yeo, Sandy Siew-Mian, and Foong-Yee Tham. "Anti-quorum sensing and antimicrobial
activities of some traditional Chinese medicinal plants commonly used in South-East Asia."
Malaysian Journal of Microbiology, 8.1 (2012): 11-20. Print.