Abstract |
Recently, we have been introduced to a contemporary compound known as silver-chitosan nanoparticles. This substance is believed to play a new role in antimicrobial control, with useful augmented capabilities. The use of silver-chitosan nanoparticles for their antimicrobial properties has led to the development of silver-chitosan based hand sanitizers. For our research, we will test the efficacy of traditional ethyl-alcohol based hand sanitizers versus a new compound with silver-chitosan nanoparticles as the active ingredient. We want to find out which of the two was not only the best at eliminating bacteria found on human hands, but which would provide the longest lasting effects. This brings our topic of interest: Can a different form of hand sanitizer yield longer lasting antimicrobial properties? |
Introduction |
Methods |
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Results |
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Discussion |
At first, we wanted to test the effectiveness of different hand soaps against each other and compare them with hand sanitizers. We diluted each subject swab up to 10-5, but no colonies formed after 10-2, making the dilutions somewhat counterproductive. As we were not obtaining enough data from our experiment and after careful examination, we realized that the dilutions yielded no results after prolonged trials. Instead, we decided to change our experimental approach by testing the longevity of only two hand sanitizers, one being ethyl-alcohol based, and compare it with silver-chitosan nanoparticles sanitizer. We would then swab subjects hands every thirty minutes, up to two hours after initial application and compare which product has the longest-lasting effect against microbes found in hands. The only instruction required in the modified experiment was to not wash hands after using the sanitizer, otherwise, the subjects were permitted to continue on personal work in the lab to simulate a normal work environment. |
Conclusion |
Initial examination of our research displays CFU counts at a sustained lower count with silver-chitosan treatment vs. the ethyl alcohol alternative. The counted bacteria found in silver-chitosan products are much lower than the ethyl alcohol sanitizer. Conceptually, the idea of a non-evaporating antimicrobial agent, like the silver-chitosan nanoparticles, should provide longer-lasting antimicrobial protection than ethyl alcohol. Although we tested a small student demographics, and time constraints were limited, the results yielded are worth consideration for this new product to be applied for antimicrobial purposes in the future. However, a two-way t-test on the average difference between CFU count before application of sanitizer and after two hours yielded a p-value too great (0.4701) to reasonably reject our null hypothesis. This leads us to conclude that there is no significant difference between the average difference in CFU count before application of sanitizer and after two hours of exposure for the two different sanitizer treatments. This t-test does not look promising for the longitudinal antimicrobial effects of silver-chitosan hand sanitizer, but the small sample size of our study (n=5) and the heavy assumptions undertaken in a two-way t-test must be considered in the interpretation of these t and p values. |
Thomas Allain, Kianelys Heredia, Anika Moffitt, Sebastian Serrano, Taha Yacoubi
Microbiology & Cell Science Department, University of Florida
References |
1) Alfaro-González, B., Ulate, D., Alvarado, R., & Argüello-Miranda, O. (2018). Chitosan-silver nanoparticles as an approach to control bacterial proliferation, spores and antibiotic-resistant bacteria. Biomedical Physics & Engineering Express 2) Chitosan / Chitin: Made in the USA with eco-friendly processes. 3) Huang, K., Wang, L., Wang, C., Yang, C., Hsieh, C., Chen, S., . . . Wang, J. (2015). Synthesis and anti-fungal effect of silver nanoparticles–chitosan composite particles. International Journal of Nanomedicine, 2685. 4) Reynolds, S. A., Levy, F., & Walker, E. S. (2006). Hand Sanitizer Alert. Emerging Infectious Diseases,12(3), 527-529. 5) Yurtoğlu, N. (2018). History Studies International Journal of History, 10(7), 241-264. |
Acknowledgements |
We would especially like to thank Austin Van Horn, President of Chitosan Health LLC., for supplying us with his product. Without Mr. Van Horn’s generosity and encouragement for scientific innovation we would not have been able to test this novel product. |
Longitudinal Antimicrobial Effectiveness of Silver-Chitosan Hand Sanitizer
Figure 1: Ethyl-alcohol vs. Silver-chitosan Treatment on Subject 1 measured for 2 hours.
Figure 2: Ethyl-Alcohol vs. Silver-Chitosan Treatment on Subject 2 measured for 2 hours.
Lift the top film and with the pipette perpendicular dispense 1 mL of sample suspension onto the center of the bottom film
Incubate for 24 hours then count all of the colonies
Apply two pumps of Hand Sanitizer to the hands
Swab subjects’ hands and transfer contents to tubes
Swab subjects’ hands again and transfer contents to tubes
| Treatment | |
CFU Diff. b/t Before and 2 Hour | Ethyl Alcohol | Silver-Chitosan |
Subject 1 | 271 | 29 |
Subject 2 | 192 | 74 |
Subject 3 | 65 | -14 |
Subject 4 | 4 | 331 |
Subject 5 | 2 | 139 |
AVG | 106.8 | 111.8 |
SD | 119.9153868 | 120.746677 |
T-value | -0.06192 | |
P-value | .476074. | |
Figure 3: Ethyl-alcohol vs. Silver-chitosan Treatment on Subject 3 measured for 2 hours.
Figure 4: Ethyl-alcohol vs. Silver-chitosan Treatment onn Subject 4 measured for 2 hours.
Figure 5: Ethyl-alcohol vs. Silver-chitosan Treatment on Subject 5 measured for 2 hours.
Figure 6: Two-way t-test on the different treatment methods.