Discovery and Identification of Antibacterial Agents for Dental Use

1
Discovery and Identification of Antibacterial
Agents for Dental Use

• Adam Kirkpatrick
• HHMI Summer 2005
• Dr. Bill Gerwick

2
Tooth Decay

• Est. 90 of U.S. have at least one cavity
• 2nd only to common cold
• 68 billion annually

3
Potential Outcomes

• Useful molecule
• Could help defeat dental disease
• Dental caries (cavities)

4
Gerwick Lab Research
5
My Research
6
Procedure

• Obtain bacteria
• The Mutans Streptococci
• Broad term
• 7 species of Streptococcus
• Cause dental caries (cavities)
• S. mutans
• ATCC UAB 308
• Choose compounds
• Culture the bacteria
• Freezer stock
• Working stock

7
Antibiotic Susceptibility Testing

• Bacteria lawn
• Impregnate disc
• Plates
• Controls
• Incubate
• Zones of inhibition

8
Results

• 21 pure compounds tested
• 1 antimicrobial pure compound
• Allolaurinterol

9
Allolaurinterol Properties

• Structure
• Name of Source Organism
• Martensia
• Laurencia
• Found
• Curacao
• 1991
• Other known activity
• Anti-cancer
• Antibiotic resistant bacteria

10
Current Project

• Other strains?
• Toxic?
• Mouthwash?

11
My Research 2nd Facet
12
Fractionation Technique

• Vacuum Liquid Chromatography (VLC)

13
Pre-fractionation of Crude Extracts to Produce
Reduced Complexity, Higher Titer Screening
Materials
14
Reverse Phase HPLC Traces from Pre-fractions A-I
Most Polar Least Polar
15
Purification Scheme
A
B
C
D
F
G
H
I
TLC
E
VLC
Solid Phase Extraction Chromatography (SPEC)
HPLC
16
Characterization of Purified Compounds

• Mass Spectrometry
• IR Spectroscopy
• 1H, 13C and 2-Dimensional NMR Spectroscopy

Photograph from http//www.biology.arizona.edu/bio
chemistry/problem_sets/aa/Graphics/MolStruct/L-leu
cine.jpg3
17
Results

• 30 organisms tested
• 9 fractions, 1 crude extract
• 300 total
• 89 antimicrobial crude extracts and fractions
• No isolated compounds
• Newly discovered molecule?

18
Results
19
Other Potential Research

• Other bacterial strains
• Human toxicity
• Antimicrobial interaction

20
Acknowledgements
21
Acknowledgements
22
You!