Team:Shanghai United HS/Description
Project Description
WHAT IS THE PROBLEM: DENTAL CARIES
Dental Caries, or tooth decay, is one of the most common diseases in the world.
Though children are mostly
exposed to dental caries, people are susceptible to this disease no matter their age. The main cause of it
is the harmful bacteria on the teeth. Bacteria, mainly S. sobrinua and S. mutans, assemble on the enamel and
form biofilm. These bacteria then feed on food left on the teeth and excrete organic acid that mineralizes
and broke the enamel. Dental Caries not only cause great pain and disruption of oral health but also
increase the risk of infection of other bodies, which will lead to diseases such as Arthritis. Current
treatments include topical fluoridization and tooth filling. However, many of them contain significant
risks. The best way of eliminating Dental Caries is unclear.
WHOW IS CLYR BE TAKEN INTO CONSIDERATION
ClyR is a common chimeric lysin that bacteriophage produces to attack target
microbes. Previous experiments have shown that ClyR can specifically eliminate Streptococcal microbes which
most caries-causing pathogens are. Therefore, its Specificity and Efficiency make ClyR a promising
treatment.
WHAT IS OUR GOAL
Figure. Flow chat of our project design
Dr. Phage's goal is to Create a gene-engineered E. coli strain containing ClyR gene
and
a-L-arabinofuranosidase(Arab) gene. Arab is an enzyme used to hydrolyze arabinose from arabinoxylans, a
carbohydrate that appears normally in foods. In the strain, ClyR gene is recombined with a promoter that can
be induced by arabinose to express ClyR outside of bacteria to function.
HOW IS OUR STRAIN CREATED
Firstly, Arab gene and ClyR gene are received and amplified through PCR and checked
with Gel electrophoresis. Then Plasmid vectors are cut with a restriction enzyme and purified with Gel
electrophoresis. DNA ligase is used to recombine both gene with different Plasmid vectors, and the plasmids
are transformed into the strain through Electric shock transformation. The effectiveness of the cell is
evaluated with the measure of arabinose concentration, A280 protein concentration, and Fluorescence
intensity by using GFP substituting ClyR.
Reference:
1,Yang, H., Linden, S. B., Wang, J., Yu, J., Nelson, D. C., & Wei, H. (2015). A
chimeolysin with extended-spectrum streptococcal host range found by an induced lysis-based rapid screening
method. Scientific Reports, 5(1). https://doi.org/10.1038/srep17257
2,Xu, J., Yang, H., Bi, Y., Li, W., Wei, H., & Li, Y. (2018). Activity of the
Chimeric Lysin ClyR against Common Gram-Positive Oral Microbes and Its Anticaries Efficacy in Rat
Models. Viruses, 10(7), 380. https://doi.org/10.3390/v10070380\
3,Selwitz, R. H., Ismail, A. I., & Pitts, N. B. (2007). Dental caries. The
Lancet, 369(9555), 51–59. https://doi.org/10.1016/s0140-6736(07)60031-2
4,Seo, E., Weibel, S., Wehkamp, J., & Oelschlaeger, T. A. (2012). Construction of
recombinant E. coli Nissle 1917 (EcN) strains for the expression and secretion of defensins. International
Journal of Medical Microbiology, 302(6), 276–287. https://doi.org/10.1016/j.ijmm.2012.05.002
5,Pitts, N. B., Zero, D. T., Marsh, P. D., Ekstrand, K., Weintraub, J. A.,
Ramos-Gomez, F., Tagami, J., Twetman, S., Tsakos, G., & Ismail, A. (2017). Dental caries. Nature Reviews
Disease Primers, 3(1). https://doi.org/10.1038/nrdp.2017.30