1. The Effects of Lysol on Living Bacteria Final Platform Presentation Ashley Pruitt Undergraduate Student Health Science Biology concentration Department of Biology Tennessee Technological University Cookeville, TN 38505

2. Introduction Known fact: Lysol kills 99.9% of living bacteria. Can this be proven? If an actual experiment tested this, will there actually be no or almost no bacteria on an item after being treated with Lysol? Other similar studies had been performed and results differed. The results differed due to substrate and disinfectant used. This prompted my curiosity of Lysol and its effects.

3. Introduction (continued) Only Lysol and one other disinfectant completely inactivated antibiotic-resistant and –susceptible bacteria (Rutala et al 2000). Lysol was effective in inactivating poliovirus (Lee et al 2007). This study showed that commercial disinfectants are not effective on Bacillus subtilis (Sagripanti and Bonifacino 1999). Only two of the six disinfectants proved to actually have any effect on killig bacteria (Acosta-Gio et al 2005). Another study again tested only Bacillus subtili; results - inhibited the growth for a short amount of time (Williams and Russell 1993).

4. Objective/Hypothesis (null) Objective: test effects of Lysol on bacteria. Alternate Hypothesis: fewer bacteria on the Lysol-treated objects. Null: no difference in the amount of bacteria before and after being treated with Lysol.

5. Method Collected samples Transferred samples to TSA plates Cleaned items properly Sprayed items with Lysol Waited 10 minutes (as directed by Lysol’s intructions. Collected samples & transferred to plates Incubated Plates for 24 hours Counted bacteria & compared effects of Lysol Ran t-test - statistical method: (http://www.socialresearchmethods.net/kb/stat_t.php)

6. Materials TSA plates Sterile cotton swabs Can of Lysol Items to test + reference Incubator

7. Pictures – Item 1: Doorknob

8. Item 2: Floor

9. Item 3- Trash Can

10. Results Bacteria Count Items: Before Lysol After Lysol Total Bacteria Count: 1-mean5.330 2-mean>1000 3-mean11.33213.22 4-mean (reference) 000 Bacteria Count Table 2.b. Matrix for the Effects of Lysol on Living Bacteria The number of bacteria present - shown in Table 2.b.

11. Results Difference in amount of bacteria both before and after treated with Lysol is shown in Figure 1. Figure 1. Amount of Bacteria Present Before and After Being Treated with Lysol

12. Discussion Results agreed with the studies by Rutala (2000) and Lee (2007), saying that Lysol did have a major effect on bacteria. Results disagreed with the studies by Sagripanti and Bonifacino (1999), Acosta-Gio (2005), and Williams and Russell (1993). The only item that bacteria remained on was the trash can. Explanation: 1) The surface of the trash can has crevices and small places for bacteria to hide in while it was being treated with Lysol. 2) More bacteria had time to infect to the treated area before the sample was taken Lysol WAS effective on killing living bacteria. Lysol lived up to its claim.

13. Conclusion Null hypothesis was rejected by results of t- test. (Null: no difference in the amount of bacteria before and after being treated with Lysol.) Alternate hypothesis was accepted: THERE WAS LESS BACTERIA AFTER BEING TREATED. SO, THERE WAS A DIFFERENCE IN THE AMOUNT OF BACTERIA PRESENT BEFORE AND AFTER BEING TREATED WITH LYSOL.