1. The Effect of Three Surface Disinfectants on Four Types of Bacteria Done By: Fatimah Al Bazron Undergraduate Student (Microbiology Concentration) Department of Biology, Tennessee Tech University Cookeville, Tennessee 38505 falbazron42@students.tntech.edu

2. Project Summary Problem: Testing the effectiveness of different disinfectants on most common types of bacteria. Objectives: To determine the best disinfectant in killing bacteria. Hypothesis: Each kind of bacteria will react differently to each disinfectant. Null-Hypothesis: There will be no differences in bacterial reactions to each disinfectant. How to Accomplish: Treat each bacterial culture with all kinds of disinfectants and measure the zone of inhibition to each one. Expected Results: The size of the zone of inhibition will be vary depending on the bacterial kind and the disinfectant used.

3. Introduction The end zone: measuring antimicrobial effectiveness with zones of inhibition (Olson 2007). Effect of antecedent growth conditions on sensitivity of Escherichia coli to chlorine dioxide (Berg et al 1982). Effectiveness of disinfectants in killing Enterobacter sakazakii in suspension, dried on the surface of stainless steel, and in a biofilm (Kim and Beuchat 2006). Antibacterial activity of hydroalcoholic extract of Terminalia chebula Retz. on different gram-positive and gram-negative bacteria (Agrawal et al 2010).

4. Objective/Hypothesis Objectives: To determine the efficiency of some disinfectants on bacterial growth. Hypothesis: The resistance of bacterial growth will be vary. Null-Hypothesis: There will be no difference on bacterial growth.

5. Methods and Materials Materials: 3 3 Disinfectants and 1 control: a ) Vesphene b) 95% Ethanol c) Bleach d) Distilled water (control) 4 4 Different bacterial cultures: a) Staphylococcus aureus (G+ cocci) b) Moraxella catarrhalis (G- Cocci) c) Bacillus cereus (G+ rod) d) Escherichia coli (G- rod) 24 TSA plates Sterile swabs Sterile filter paper discs Ruler

6. Methods and Materials Cont. Procedure: Swab each bacterial culture on 6 agar plates. Divide each plate into 4 quadrants: water, Vesphene, 95%Ethanol, and Bleach. Place filter paper discs saturated with each tested disinfectant into the center of its corresponding quadrant. Incubate the plates for 24-48 h at 37°C. Using the ruler, measure the diameter of the zone of inhibition around the discs in each plate and record the data.

7. Methods and Materials Cont. Experimental Design Matrix Data Forms Average Bacterial Resistant (Excel 2007)

8. Expected Results and Benefits Each bacteria will react differently to each disinfectant. The size of the zone of inhibition will be different among bacterial kinds. Benefits: for Health Care Providers.

9. Project Timeline Timeline