Rapid MTB Strip Test Detects Tuberculosis in Less Than an Hour without Special Tools

By LabMedica International staff writers
Posted on 01 Jun 2023

Image: The rapid MTB strip test for tuberculosis can identify TB patients within two hours (Photo courtesy of Chulalongkorn University)

Tuberculosis (TB), a highly infectious disease, continues to pose significant challenges to public health worldwide. TB is caused by a bacterium known as "Mycobacterium tuberculosis," spreading through tiny respiratory droplets when a TB-infected individual coughs, sneezes, or talks. Given its high contagion rate, one of the key strategies to curb TB is the early identification of infected patients, thus preventing further spread. Existing TB testing methods, while beneficial, present several drawbacks such as low sensitivity, prolonged wait times for results, and the necessity for specialized lab personnel. To combat these challenges, a research team has created a highly sensitive strip test that can detect TB within two hours.

The MTB Strip TB Test Kit developed by researchers at Chulalongkorn University (Bangkok, Thailand) leverages the technique of genetic material amplification at a constant temperature, alongside a heat box, a common piece of equipment in most labs. This approach is even accessible to small-scale hospitals. To use the MTB Strip TB Test Kit, the patient's sputum is first collected, from which DNA is extracted for use as a template. A specially-crafted primer is used to amplify the genetic material in the pathogen's DNA present in the patient's sputum, a process facilitated by a recombinase polymerase amplification technique that takes merely 20-40 minutes at 37 degrees Celsius. The resulting amplified genetic material is then introduced to the test strip, which displays positive or negative results.

The MTB Strip delivers results with an accuracy rate of up to 96% compared to Realtime PCR and other commonly used acid-resistant dye methods. Moreover, the kit proves more cost-effective than molecular biology tests as it doesn't require specific tools such as a thermocycler. Notably, the MTB Strip demonstrates high sensitivity to TB, capable of detecting even minimal amounts of TB present in sputum. Furthermore, the test is user-friendly, delivers quick and precise results within an hour that can be easily read with the naked eye, and requires no specialized equipment. Despite the satisfactory performance of the MTB Strip kit, the researchers aim to enhance its sensitivity by simplifying the DNA extraction process for use as the kit primer. Currently, they are working on expanding TB and related disease testing by creating an easier-to-use DNA extraction kit and a TB test kit capable of identifying drug-resistant TB strains from the outset, thus allowing for more specific treatment plans.

“We are currently conducting in-depth research on the genetic modification of tuberculosis using a novel technique of genetic modification for a living organism called CRISPR Cas-9 Interference to modify certain TB genes, making the infection less aggressive and more responsive to antituberculosis drugs. CRISPR Cas-9 Interference can be used in conjunction with current antituberculosis drugs,” said Dr. Panan Ratthawongjirakul, Associate Professor at Chulalongkorn University.

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Chulalongkorn University