1. ANTIMICROBIAL PROPERTIES OF VARIOUS GREEN TEA PRODUCTS WITH AND WITHOUT THE ADDITION OF SUGAR
T3 Members:
Samantha Acevedo, Conan Chen, Ethan France, Brian Goldspiel, Anna Kim, Amanda Li, Florence Ma, Sana Siddiqui, Stephanie Tarlowe, Anthony Yakely, Leanna Zhan
Advisor: Mrs. Rachel Sandler
Assistant: Gillian Bradley

2. What is Green Tea? Camellia sinensis plant leaves Fermentation Types
Green, oolong, and black teas
Types
Matcha: powdered leaves
Sencha: Uji leaves
Loose: dried leaves
Bagged: filtered tea bag
Bottled: Snapple ® brand
Instant: powdered mix

3. Chemical Composition

4. Streptococcus mutans Gram-positive bacteria produce lactic acid
Gram-positive bacteria produce lactic acid
Breaks down tooth enamel
Causes cavities and bad breath
Unique genes serve as drug targets

5. Health Benefits Multiple studies have been conducted
LDL
Obesity
Diabetes
Cancer
Dental Health
Antimicrobial properties
due to low degree of fermentation
May destroy catechins

6. HYPOTHESES

7. Preparation of Teas 240 mL boiled, deionized water Cooled to 90°
Steep 15 minutes
15 g sugar per sample
Diet Snapple ® On-the-Go powder

8. Process of Diffusion Cover plates with bacterial lawn
None on control
Soak disks 5 minutes
Place on plate
Incubate ~48 hours at 37° C
Measure zones of inhibition

9. In Vitro Procedure Sterilize loop Inoculate and make line on plate
Submerge loop in liquid
2 minutes
10 second intervals
5 in liquid, 5 in air
Stir gently
Scope ®
30 seconds
Constant agitation
Swab loop and make line on plate

10. Paper Disk Diffusion: Zone of Inhibition
Scope ® mouthwash
1.77 cm diameter
Antimicrobial compounds
Alcohol
Poloaxamer
Polysorbate
Sodium benzoate
No observable zone of inhibition around disks of any teas

11. Paper Disk Diffusion: Possible Errors
Contaminated plates
Open disks exposed to fungus in lab
Lapses in aseptic technique
Excess liquid on disks

12. Paper Disk Diffusion: Zone of Growth
Lipton ® tea with sugar
0.95 cm diameter
No growth on control
Sugar may have boosted
Inconclusive Gram stain
More research needed

13. In Vitro: Results Control had more bacteria before than after
All results compared to control
Less bacteria not necessarily significant
Sugar appeared to have no effect
Control (Water) Matcha with Sugar

14. In Vitro: Best Results
Loose Leaves Scope ®

15. In Vitro: Results Discussion
More subjective and qualitative
Visual observation
Little clear evidence of antimicrobial benefits against S. mutans
Loose tea leaves had strongest effect

16. In Vitro: Alternate Method for Scope ®
Known antibacterial agent
Loop immersed in Scope ® for 30 seconds
Simulated difference between rinsing with mouthwash and sipping a beverage
May have attributed to differing results

17. In Vitro: Errors
Preparation method
Small sample size
Discrepancies

18. Future Research Different preparation methods
Potency of green tea on other microbes
Chemical compositions of teas
Loose leaf tea (in vitro)
Effects of sugar
Modeled after realistic experience
Different concentrations

19. Conclusions Scope ® is most effective Loose sencha leaves (in vitro)
Sugar inconclusive
Possibly detrimental in one case

20. Acknowledgements John and Laura Overdeck
The Crimmins Family Charitable Foundation
NJGSS Alumni and Parents ( )
Bristol-Myers Squibb
Roche
Kinder Morgan
Bain Capital
GlaxoSmithKline
Novartis
Bayer HealthCare
Dr. Miyamoto, Dr. Surace, Dr. Quinn, Myrna Papier, Mrs. Sandler, Gillian Bradley

21. QUESTIONS