Tiny Robot Made of Gold Could Help with Tuberculosis Treatment

A new tiny robot could help identify drug-resistant tuberculosis more efficiently.

Scientists from Brock University in Canada have improved a microscopic robot they created in 2016 to help solve this unique problem, according to a press release published Monday. In a paper published July 2 in the journal Chemical Science, the team led by Brock assistant professor of chemistry Feng Li detailed how the nanomachine couldpotentially help solve a complicated problem in tuberculosis treatment.

Tuberculosis is one of the top 10 causes of death in the world, according to the World Health Organization (WHO). About 1.7 million people died from it in 2016, and it's the leading cause of death in people who are HIV-positive, with tuberculosis causing over 40 percent of deaths in people with HIV. Although 53 million lives were saved through diagnosis and treatment between 2000 and 2016, tuberculosis incidence is falling only about 2 percent each year.

Drug-resistant tuberculosis is one reason the disease has been so hard to eradicate. The WHO estimated that in 2016, 600,000 new cases of tuberculosis cases were resistant to the most effective drug available, rifampicin. Of those 600,000 people, 240,000 died. Drug resistance is often caused because patients don't complete their full treatment plan before the bacterium that causes tuberculosis is killed. In these cases, doctors need to switch to a different tuberculosis treatment as soon as possible. By detecting these drug-resistant cases earlier, more lives could be saved.

The 2016 version ofBrock University's microscopic robot could find diseases in a blood sample within just 30 minutes. However, in this new and improved version, the robot can also detect mutations in tuberculosis-causing bacteria, potentially revealing within an hour if the bacteria is drug resistant to first-line tuberculosis antibiotics, like rifampicin. Current tests reveal resistance within two hours.

A tuberculosis patient holds medicines received from the government's tuberculosis center in Rawalpindi, Pakistan. Drug-resistant tuberculosis is one reason the disease has been so hard to eradicate. FAISAL MAHMOOD/REUTERS

To create the robot, the scientists first used 20 nanometers of gold, or about the diameter of eight strands of DNA. Strands of DNA of varying lengths are attached to the gold particle and create and control the nanomachine. The long strands of DNA find differences between nucleotides in the genes of the tuberculosis bacteria. Differences between nucleotides indicate a mutation in the genes and potential drug-resistant capabilities. To signal a mutation, the short DNA strands carry fluorescent signal reporters that will glow.

This robot could replace the test that has been used to find drug-resistant tuberculosis, potentially cutting the detection time in half. This means a faster diagnosis, a new treatment for the patient and a higher chance of survival.

The WHO's goal is to reach a 4 to 5 percent annual decline in tuberculosis by 2020. As that deadline approaches, new research and diagnostic methods will grow even more necessary.