colloquium updated
TRANSCRIPT
Household Items as Emergency Antiseptics
Jesse Austin
What is the goal of the experiment?
• The purpose of this experiment was to find alternatives to traditional antiseptics in case there is an emergency and there are no other antiseptics available.
Antiseptic vs Disinfectant
• Bacterial growth is defined by an increase in cell count, rather than an increase in cell size.• Antiseptics prevent the growth of bacteria in on living
surfaces, like our skin.• Disinfectants prevent the growth of bacteria on nonliving
surfaces like a table lab bench.
Why early treatment is important.
• It only takes a small amount of bacteria to start an infection if it is allowed to spread. • Early treatment is crucial for preventing the spread of
bacteria, especially with accidents where there is an open wound.
Types of Antimicrobials
• Bacteriostatic Antimicrobials• Prevent any further growth of the bacteria but doesn’t necessarily kill
the bacteria• Bactericidal Antimicrobials• Kills any present bacteria so that even after the antimicrobial is
removed there can’t be any more growth
Bacteriostatic vs Bactericidal
Test Organisms
• Escherichia coli• Better known as E. coli. Responsible for a lot of food poisoning cases.
Test Organisms
• Staphylococcus aureus• Better known as Staph, the causative agent for Staph infections.
Test Organisms
• Salmonella typhimurium• Better known as just Salmonella, the biggest reason not to eat raw
poultry.
Control Substances• These substances are known antimicrobials and were used to compare
what would actually be considered as good inhibition for bacterial growth• Antibacterial hand soap• Benzethonmium chloride
• Neosporin• Bacitracin• Neomycin• Polymyxin
Test Substances• Windex• Pure Vanilla Extract• Drinking Alcohol• Garlic• Red Onion• Yellow Onion• White Vinegar• Honey• Lemon Juice• Lime Juice
Methods: Phase 1
• The first part of the experiment was to test the plausibility of each test substance as an antimicrobial. • To test this, 1-2 isolated colonies from each of the test
organisms was spread onto their own respective plates containing solid growth medium.• The plates were then divided into separate areas and 10
microliters of test or control substances were spotted into their respective areas. • The plates were then incubated for 24 hours and the amount
of growth was recorded.
Methods: Phase 1
Results: Phase 1Escherichia coli Staphylococcus
aureusSalmonella typhimurium
Antibacterial hand soap
++ ++ ++
Neosporin + + +Drinking Alcohol - - -Garlic - - -Red Onion - + -Vanilla Extract - - -Windex ++ - ++Yellow Onion - + -White Vinegar + + ++Honey + - -Lemon Juice + ++ ++Lime Juice + ++ +++ indicates good inhibition, + indicates some inhibition, - indicates no inhibition.
Methods: Phase 2
• The concentration of test substance needed to be an effective antimicrobial was tested by adding a known amount of bacteria from a liquid culture to increasing concentrations of each test substance.
Methods: Phase 2
• Increasing concentrations of test substance were made by preparing different ratios of saline solution and test substance.• The range of concentrations was from 10%-90%. This was
created by adding 100-800 microliters of saline solution with 100-800 microliters of test substance. • 100 microliters of bacterial liquid culture was then added to
each test concentration for 5 minutes. • After 5 minutes 100 microliters of the solution was spread
onto a plate containing solid growth medium and incubated for 24 hours.
Results: Phase 2Escherichia coli
10% 20% 30% 40% 50% 60% 70% 80%Windex ~25
0~240
17 0 0 0 0 0
Red Onion TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Yellow Onion
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Honey TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Vinegar TNTC
TNTC
TNTC
~100
3 0 0 0
Lemon Juice
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Lime Juice TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Number of colonies counted after 24 hour incubation period.TNTC indicates Too Numerous to Count
Results: Phase 2Staphylococcus aureus
10% 20% 30% 40% 50% 60% 70% 80%Windex 86 64 80 59 72 63 71 54Red Onion 121 128 96 144 80 96 120 128Yellow Onion*
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Honey 33 38 72 14 32 32 15 4Vinegar 46 10 12 0 0 0 0 0Lemon Juice 64 5 5 5 3 2 1 0Lime Juice 3 1 0 0 0 0 0 0
Number of colonies counted after 24 hour incubation period.TNTC indicates Too Numerous to Count.* Indicates plates where contamination was present
Results: Phase 2Salmonella typhimurium
10% 20% 30% 40% 50% 60% 70% 80%Windex 89 2 0 0 0 0 0 0Red Onion TNT
CTNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Yellow Onion
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Honey TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Vinegar TNTC
TNTC
0 0 0 0 0 0
Lemon Juice
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Lime Juice TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
TNTC
Number of colonies counted after 24 hour incubation period.TNTC indicates Too Numerous to Count
Conclusion
• 4 household items were shown to be effective antimicrobials: Windex, White Vinegar, Lemon Juice, and Lime Juice. • Vinegar was the most effective overall, inhibiting growth of all
3 bacteria by 60% concentration.• These are not meant to replace traditional antiseptics but
intended to be used when emergency treatment is needed and there isn’t another option.
Acknowledgements
• Dr. Adam Silver• Yonina Bykov• Dean’s Research Fund for Undergraduate Research