If a Tick Bites You in the Forest, Do You Glow?

Rocky Mountain spotted fever (RMSF), a bacterial infection, is one of the most common fatal tick-borne diseases in the United States. RMSF claims the lives of roughly 5% of its victims (Columbia University, 2018). Rickettsia rickettsii, the strain responsible for RMSF is found primarily in the American dog tick – it lives on our pets and in our surroundings.  This disease is easily treatable with the antibiotic doxycycline, but treatment must be started within the first five days of contraction or the risk of fatality increases exponentially (CDC). The issue lies in the diagnosis. RMSF appears with nonspecific symptoms, which can include: fever, rash, headache, nausea, lack of appetite, etc., which make it difficult to diagnose. Currently, there are no laboratory tests available that are both rapid and sensitive enough to provide useful diagnostic assistance to the examining physician (Columbia University, 2018). Due to these nondescript symptoms and lack of diagnostic technology, physicians rely on patient history to support their clinical observations. However, this can be a cumbersome system when you’re the one that’s bitten, and you’d like to just have an answer!

Researchers at The University of Texas at Austin are streamlining the path to treatment using a new molecular diagnostic tool, based on amplifying and detecting the Rickettsia DNA found in an infected tick.  Dr. Sanchita Bhadra has pioneered a nucleic acid strand displacement mechanism known as LAMP-OSD that allows DNA to be amplified while being held at a constant temperature. This is substantially easier than the diagnostics mainstay, PCR, which requires a complicated instrument and would be hard to use in a camp or at a field station, where the answer would be most needed.

In an exciting demonstration of the prowess of UT’s commitment to experiential learning, an undergraduate student in the DIY Diagnostics Lab, Simren Lakhotia, has adopted Dr. Bhadra’s methodology, improved upon it, and as part of a so-called ‘iTeam’ in the Inventors Program of the Texas Institute for Discovery Education (TIDES) is attempting to translate it into real-world use.  Simren has developed a fluorescent heat-stable DNA probe, that allows her to readily visualize an infected tick sample, essentially making them glow-in-the-dark (Figure 1). 

As the assay is further developed and distributed, if you’re the one bitten you can just drop a tick into a tube to test it for infection.  This will provide valuable information for you, the patient, as you further traverse the path to treatment. More importantly, this is a paradigm for the ‘democratization of diagnostics,’ for putting the opportunity (and responsibility) for health care into our own hands.  Additional assays that would allow testing of mosquitoes for Zika, discern the presence of contamination in groundwater, or give you insights into your exposure to mold in your home are on their way. Ticks may ‘light the way,’ but what starts here with students will change the world.