In the Zone: The Relative Efficacy of Antiseptics and Disinfectants

Report of Results with Discussion

Introduction

6 Bacterial Strains

6 Antibacterial AgentsE. Coli S. Aureus P. VulgarisB. Cereus E. FaecilisP.

Aeruginosa

Hypothesis: That all of the antiseptic and disinfectant agents will be effective against all of the bacterial strains

Example of Experimental Plate

10% Bleach

Hand Sanitizer

Spic & Span

Mouthwash

Rubbing AlcoholHydrogen Peroxide

Sensi-disk

Agar Plate

Measuring the Zone of Inhibition

Results Table

Antibacterial Agent Zone of Inhibition (mm)Bacterial

Strain E. ColiS. Aureus

P. aerugin

P. Vulgaris

B. Cereus

E. Faecilis

Hand Sanitizer 12.5 0 0 0 0 0

Hydrogen Peroxide 1 15.5 2 14 9 15

Mouth Wash 0 0 0 0 0 0

Rubbing Alcohol 0 0 0 0 0 0

10% Bleach 0 0 1 3 0 2

Spic & Span 2 2 0 0 6.5 0

Graph of Results

E. Coli S. Aureus P. aerugin P. Vulgaris B. Cereus E. Faecilis0

2

4

6

8

10

12

14

16

18

Hand Sanitizer

Hydrogen Peroxide

Mouth Wash

Rubbing Alcohol

10% Bleach

Spic & Span

Bacterial Strain

Dia

met

er o

f Zon

e of

Inhi

bitio

n (m

m)

Summary of Results

Hydrogen Peroxide was, comparatively, the most consistently and highly effective antibacterial agent tested

Spic and Span as well as bleach come in second and third

Average Zones of InhibitionAntibacterial

AgentAverage Zone of

Inhibition

Hand Sanitizer 2.1

Hydrogen Peroxide 9.4

Mouth Wash 0.0

Rubbing Alcohol 0.0

10% Bleach 1.0

Spic & Span 1.75

Holistic Analysis

Antibacterial Agent

Average Zone of Inhibition

Consistency Coefficient

(# of bacterial strains effective against/total

bacterial strains)

Total Efficacy Rating

((Coefficient) ( Avg.

Zone))

Hand Sanitizer 2.1 0.17 0.35

Hydrogen Peroxide 9.4 1 9.42

Mouth Wash 0.0 0 0.00

Rubbing Alcohol 0.0 0 0.00

10% Bleach 1.0 0.5 0.50

Spic & Span 1.75 0.5 0.88

Contrary to Expectations

?

Acknowledgements

Lab Group Kelly Cinelli Eric Carpizo Dan Dehelian

Lab Instructor Dr. E. Dawley

T.A. Chris Frymoyer

UC Biology Department

Sources Cited

Image Credits in Order of Appearance Bacteria pictures:

▪ http://www.freedrinkingwater.com/Images-Test/E-Coli01.jpg▪ http://www.vanderbilt.edu/exploration/resources/staph_aureus_800.jpg▪ http://pseudomonas.com/images/paeruginosa.jpg▪ http://www.ciriscience.org/thumbimage.php?id=155▪ https://

encrypted-tbn0.google.com/images?q=tbn:ANd9GcT2cuGZgkF4U7SA7yRW3HDoopkUlbqd-FVmuN6AlHIarWFIJJiYXA

▪ http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Enterococcus_faecalis20023-300.jpg/220px-Enterococcus_faecalis20023-300.jpg

Antibacterial Pictures:▪ https://

encryptedtbn2.google.com/images?q=tbn:ANd9GcSfNvZpXJob0xfyOAzGAO1NQdtMSAb5IGrU6TpxE0jc89A1RiYn

▪ http://substuff.files.wordpress.com/2010/11/spicspancleaner.jpg▪ http://www.germx.com/data/photos/8oz_Aloe.jpg▪ http://www.mcguffmedical.com/Images/Images550/003208%20Hydrogen%20Peroxide%203

%20Percent,%20Topical%20USP,%2016%20Ounce%20Bottle,%20Each%20McGuffMedical.com.jpg

▪ http://www.scopemouthwash.com/images/crest-products/large/scope-white-mouthwash-mint-splash.png

▪ http://maryl.uibcsites.com/files/2011/05/Alcohol-Isopropyl.jpg

Zone of Inhibition Diagram:▪ Ursinus Bio Department Lab 4 instructions

Sources Continued

Lab 2.3 & 2.4 Procedure from the Ursinus Bio Department Material Consulted for Discussion

Hand Gels Falter C. B. Science News , Vol. 169, No. 23 (Jun. 10, 2006), p. 366 http://zack2.ursinus.edu:2075/stable/pdfplus/10.1086/503455.pdf?acceptTC=true

▪ Efficacy of Alcohol‐Based Hand Sanitizers Against Fungi and Viruses E. Fendler and P. Groziak Infection Control and Hospital Epidemiology , Vol. 23, No. 2 (February 2002), pp. 61-62