Diarrheal diseases are the leading cause of death for children under the age of five. In 2017, 1.6 million people died of diarrheal infections alone. Major contributors to these diseases are E. coli infections. E. coli infections can be easily avoided but identifying a water source contaminated with E. coli often needs a lab or cheaper, but less accurate at-home tests.
Using the CRISPR-Cas9 gene editing technique along with the Green Fluorescence Protein (GFP), I was able to create a new method of detecting E. coli accurately without the cost of sending a sample to a lab. It works by cutting the E. coli DNA at the lacZ gene and then inserting the GFP in between. This will result in the GFP being edited into the E. coli genome. The GFP acts as a tagging mechanism, as when ultra-violet light it shone on organisms that contain the GFP, they will glow green. Therefore, the test will be positive if the suspected culture of E. coli will glow green under a blacklight.
To model the test, I used a simulation called Benchling. With the simulation, I identified the lacZ gene in E. coli, the lacZ promoter, and thus I deduced the target DNA. After identifying the target DNA, I determined the protospacer adjacent motif, the segment where CRISPR-Cas9 will cut.
This innovation is important because it allows those living in less fortunate and more vulnerable areas to have access to effective E. coli testing to keep themselves and their families healthy.
What inspired you (or your team)?
It is no secret that a large portion of the world population does not have access to clean water. This doesn’t extend to just third-world countries, too. In Canada, those living in Northern or remote cities get very regular contaminated water advisories. Contaminated water can be deadly, whether it be from lead poisoning or bacterial infections. I came across a statistic of how many children die of diarrheal diseases each year and I was truly shocked; something that I think of as an inconvenience was killing millions of people. I learned that E. coli infections were responsible for many of these deaths, specifically E. coli contaminated water.
E. coli is vital to our digestive system, but when it enters different areas of our body, it can be very dangerous. Killing E. coli in contaminated water is easy—just boil the water. But detecting E. coli is a very different story. For something so common, I learned that there was no accurate and real cost-effective way to test for E. coli. It can either be tested in a lab, where scientists take a sample and let the sample grow for long enough before examining it under a microscope to see if there are E. coli present or with at-home, litmus paper-like kits, which are cheaper but often need more lab testing. If you are living in a third-world country or in a remote area (arguably the people the most vulnerable to these infections), these tests may not be an option.
I have a huge passion for gene editing and all the different implications gene editing techniques had. Using my knowledge of the CRISPR-Cas9 gene editing technique, I was able to come up with a solution that takes techniques that have already been established and applied them in a way they haven’t been applied to before.