Effects of Facial Cleaner on E. coli and Staph By Ryan Dillon Central Catholic High School Grade 9

Problem With cosmetics being investigated, does Cetaphil Facial Cleaner have an effect on normal human microbial flora?

To test the effects of Cetaphil facial cleaner on E.coli and Staph Purpose To test the effects of Cetaphil facial cleaner on E.coli and Staph

Microbial Flora Little is known about the association between humans and their flora Effects are mutualistic, parasitic, pathogenic and commensal Provide nutritional and digestive benefits, secrete vitamins, stimulate antibody production, and protect against pathogenic microbes

Hypotheses The null hypothesis of the experiment is that the facial cleaner will not have an effect on the growth of E. Coli and Staph The alternative hypothesis is that the facial cleaner will have an effect on the growth of E. Coli and Staph

Escherichia Coli Major cause of food-borne illness 70,000 cases/year in U.S. Consumption of undercooked meats Consumption of contaminated vegetables or unpasteurized milk Also resides in fecal matter. Most studied bacteria Resides in the digestive tract of animals. Can survive outside of host organism Not all strains of E.coli can result in sickness or disease

Staphylococcus Epidermidis Staph is a Gram-positive bacterium Part of the normal human flora, usually the skin flora Not usually pathogenic but can be if a person with a weakened immune system is infected Patients usually infected through hospitals

Prevention and Treatment of E.Coli Washing hands Thorough cooking of food Washing food Food employees washing hands and wearing gloves Antibiotics

Materials Permanent Marker Vortex Incubator Sterile tips Tube Racks Micropipettes P1000 and P200 E. coli Staph Sterile Luria broth Agar Plates (1% Tryptone, 0.5% Yeast Extract, 1% NaCl) Spreaders Ethanol 10% Stock Clearasil Facial Cleaner Permanent Marker Vortex Incubator Sterile tips Tube Racks

Procedure Both bacteria were grown until a density of 50 klett spectrophotometer density was reached. This was approximately 10^8 cells/mL Both cultures were diluted in sterile dilution fluid to a concentration of approximately 10^5 cells/mL Took a 10% stock of the Cetaphil Facial Cleaner Concentrations were then added to the test tubes and then 0.1 ml of bacteria were added to their tubes. The concentrations were vortexed then added to the plates. (Multiple people spread plates at the same time to prevent lag time)

Results Percentage of variable E. coli Staph Control 341 210 O.1% 299 267 1% 274 164 5% 93 140 10% 70 128

Number of Colonies P-Value of Staph – 1.4e-05 P-Value of E. coli – 0

Dunnett’s Test Results: Staph Concentration T-Value T-Critical Results 0.10% 1.59 3.48 Non significant 1% 3.69 Significant 5% 5.60 10% 6.20

Dunnett’s Test Results: E. coli Concentration T-Value T-Critical Results 0.10% 1.69 3.48 Non Significant 1% 5.11 Significant 5% 18.75 10% 21.44

Conclusions The conclusion of this experiment is that the higher the concentration the less bacteria could grow and survive. The alternate hypothesis was significant in all the concentrations for both bacteria besides 0.10%

Limitations/Extensions Limitations: High concentrations not tested, Only two species were tested, and slight variation in the spreading of the plates. Extensions: More trials, Different concentrations, using yeast, algae, or other bacterium, and two variables not just one

One-Way Anova of Staph

One-Way Anova of E. coli

Works Cited Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 21 Dec. 2015. Web. 27 Jan. 2016. "Staph Infection (Cellulitis) Contagious, Causes, Symptoms, Diagnosis, and Treatment of Staph Infections." WebMD. WebMD, n.d. Web. 27 Jan. 2016. "E. Coli Bacteria Infection Symptoms, Causes, Treatments." WebMD. WebMD, n.d. Web. 27 Jan. 2016.