Download Richardson CCHS Effects of Acne Medications on E. coli

Effects of Acne
Medications on E. Coli
Lewis Richardson
Central Catholic High School
Grade 9
Problem
What effect do acne
medications have on the
survivorship of E. coli?
Hydrogen Peroxide (3%)
•
One of the most commonly
used chemicals for
sterilization.
•
Targets germs such as
staph, strep, Salmonella,
and E. coli.
•
Used for clearing acne,
whitening teeth, lightening
hair, and other common
uses around the house.
Salicylic acid (0.5%)
•
One of the most commonly used chemicals for
treating acne.
•
Colorless crystalline organic acid
•
Widely used in organic synthesis and functions as a
plant hormone.
Escherichia Coli
•
Large and diverse group of
gram (-) bacteria.
•
Surrounded by an extra cell
wall composed of
lipopolysaccharides.
•
Free living, symbiots, or
pathogens.
•
Common prokaryotic cell
model.
•
Most are not pathogenic.
Acne Vulgaris
❖
Common human skin disease
❖
Areas of skin with seborrhea (scaly red skin), comedones
(blackheads and whiteheads), pimples, and possible scarring
❖
Excess amount of sebum and dead skin cells: bacteria can thrive
❖
Caused by bacteria, hormones, diet, stress, and medications
❖
Anaerobic bacteria P. acnes, found in sebaceous glands, attributed
to acne
❖
Treated by over-the-counter and prescription medications in the
form of a pill or wash
Purpose
Determine which type of acne medication
works the best at a given concentration.
Previous Studies
❖
Experiment conducted by the University of Southern
California on the effects of home remedy acne methods
in comparison to professional products.
❖
Proactiv tests run using E. coli as an acne substitute
Hypothesis
•
Null: The variables will not alter the growth
or survivorship of E. coli.
•
Alternative: increasing concentrations of the
variables will significantly reduce
survivorship of E. coli.
Materials
•
•
E. coli DH5 Alpha
LB agar plates
•
Micropipettes
•
Sterile Pipette tips
•
Sterile Test Tubes
•
Sterile Spreader Bars
•
Incubator
•
Bunsen burner
•
Hydrogen Peroxide (3%)
•
Salicylic Acid (0.5%)
•
SDF (Sterile Dilution Fluid),
(100 mM KH2PO4, 100 mM
K2HPO4, 10 mM MgSO4, 1
mM NaCl)
•
Vortex
•
Ethanol (sterilization of
instruments)
•
Matches
Procedure
1. Labeled all plates and flasks before
experimentation with "Control, 0.1%, 1%,
5%, & 10%."
2. The variables, microbe, and SDF were added
to create mixtures with the desired
concentrations:
Mixtures
Control
Variable
0.1%
1%
10%
Sterile
Water
9.9 mL
9.89 mL
9.8 mL
8.9 mL
Toxic Agent
(Acne
Medication)
0 mL
0.01 mL
0.1 mL
1 mL
E. Coli
0.1 mL
0.1 mL
0.1 mL
0.1 mL
Procedure (cont.)
3. Dipped spreader into ethanol and burned with
matches or Bunsen burner to sterilize it.
4. Evenly spread the mixture on the plate with the sterile
spreader bar.
5. Closed the plate and put into incubator to allow
overnight growth
6. Counted the colonies that have grown on the plates
What is an ANOVA?
❖
An ANOVA test is used to search for significant
variance between data
❖
Used to determine if there is significant variation
between the mean values of groups
❖
If the P- value is smaller than the alpha value
(.05), then at least two of the means varied
significantly
Hydrogen Peroxide Effect on E. Coli
Survivorship
P Value=1.02E-14
Number of Surviving Colonies
800
754
753
600
400
200
0
Control
0.1%
91
3
1%
10%
Concentrations of Acne Medications
Dunnett's Test (Hydrogen Peroxide)
T-Critical=4.0
Variable
Concentration
T-Values
Significant?
0.1%
3.596
Not Significant
1%
32.6
Significant
10%
37.0
Significant
Salicylic Acid Effect on E. Coli
Survivorship
P-Value= 0.013546
Number of Surviving Colonies
800
754
681
600
697
527
400
200
0
Control
0.1%
1%
Concentrations of Acne Medications
10%
Dunnett's test (Salicylic acid)
T-Critical=4.0
Variable
Concentration
T-Value
Significant?
0.1%
3.59
Not Significant
1%
2.80
Not Significant
10%
11.2
Significant
Conclusions
❖
The 1% and 10% concentrations of hydrogen
peroxide significantly lessened the E. Coli
survivorship while 0.1% was not significant.
❖
The 10% concentration of Salicylic acid significantly
lessened the E. Coli survivorship while the 0.1% &
1% did not.
❖
Reject the Null Hypothesis, Accept the Alternative
hypothesis.
Limitations
❖
Only one model used
❖
Test tubes may have been contaminated
when plating mixtures.
❖
Only survivorship was tested
❖
Only two kinds of acne medications used
Extensions
❖
More acne products could have been used with
more varying concentrations.
❖
More replicates could have been used to ensure
human error or contamination was not a factor in
the suvivorship.
❖
A growth analysis could have been conducted
❖
Synergistic effects with other drugs
❖
Vary exposure times
❖
Agar infusion or surface wipe exposure
Works Cited
❖
Salicylic Acid.” ChemistryDaily.com. Web. 24 Dec. 2014
❖
“CLINDAMYCIN PHOSPHATE lotion CLINDAMYCIN PHOSPHATE solution CLINDAMYCIN
PHOSPHATE gel” Daily Med Current Medication Information. Web. 24 Dec. 2014
❖
Fredrick, Kurt, Shinichiro Shoji, and Sarah E. Walker. “Ribosomal Translocation: One Step Closer to
the Molecular Mechanism.” ACS Chem. Biol. 93-107. Web. 24 Dec. 2014
❖
Guay, David RP. “Topical clindamycin in the management of acne vulgaris.” Web. 24 Dec. 2014
❖
Kishi, Kenji, and Kazyhiro Hirai. “Clindamycin Suppresses Endotoxin Released by CeftazidimeTreated Escherichia coli O55:B5 and Subsequent Production of Tumor Necrosis Factor Alpha and
Interleukin-1 β.” Antimicrobial Agents and Chemotherapy. 616-622. Web. 24 Dec. 2014
❖
Nishijima, S, I Kurokawa, N Katoh, and K Watanabe. “The bacteriology of acne vulgaris and
antimicrobial susceptibility of Propionibacterium acnes and Staphylococcus epidermidis isolated from
acne lesions.” n. p. Web. 24 Dec. 2014
❖
Owens, CD, K Stoessel. “Surgical site infections: epidemiology, microbiology and prevention.” Journal
of Hospital Infection 2008. Web. 24 Dec. 2014
ANOVA (Hydrogen Peroxide)
ANOVA Salicylic Acid
ANOVA (0.1% concentrations)
ANOVA (1% concentrations)
ANOVA (10% concentrations)