A press release
issued by the ACS detailed the new test which they say will make the diagnosis of TB simpler, faster, and more accurate. Current tests for the infection include chest X-ray, which is rarely available in the poorer and worst-hit regions of South Asia and Africa, as well as tests of blood, saliva, or skin, which need to be sent to a lab. These tests can be prone to errors and results can take a long time to come back to the doctors.
This novel TB test emerged as researcher Carolyn R. Bertozzi, PhD, and her team at Stanford were studying the
glycolipids in TB. Glycolipids are molecules in the cell walls of the bacteria that cause the disease, and are made up of the sugar trehalose linked with lipids or fats. When the researchers exposed modified forms of trehalose to the TB bacteria, the microbes would metabolize and integrate them into their glycolipids. By attaching a fluorescent green dye molecule to the sugars, they found that the bacteria cell that picks it up then glows green.
With this discovery, the researchers saw a potential new approach to testing saliva for TB, but needed a more sensitive dye that did not tint every component of the saliva. Using instead a solvatochromic dye that only glows once inside the cell walls and attaching it to the trehalose, the researchers found that they had developed a quick and easy test for TB that can give a speedy diagnosis. After adding the dye mixture to a saliva sample from a patient, a technician can note a positive diagnosis if anything appears to glow under the microscope in as little as one hour.
Of note is that this new dye test only works on live cells, and so it can indicate when a treatment for TB is working and the bacteria cells are dying.
Trial tests for this new diagnostic tool for TB began in South Africa in June. The Stanford research team is currently building on their research to hopefully shed light on new ways to battle TB.
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