CRISPR-Based Tuberculosis Test Uses Mouth Swab to Simplify Screening

Tuberculosis remains the world’s deadliest infectious disease, with more than 10 million people falling ill annually and about 40% of cases going undiagnosed. Current testing depends on sputum samples, which are difficult to collect and impossible in many patients, including children, HIV-positive individuals, and those with extrapulmonary TB. Now, researchers have refined a gene-based method that enables accurate detection of TB from simple, non-invasive samples such as tongue swabs.

Researchers at Tulane University (New Orleans, LA, USA) have developed the ActCRISPR-TB test to enhance sensitivity for samples with very low bacterial counts. The test uses a multi-guide RNA Cas12a assay that amplifies TB DNA signals for faster detection. Designed as a “one-pot” approach, it requires no laboratory or trained staff and produces results in under an hour, similar to the simplicity of a rapid COVID-19 test.

Image: The genetic-based method enables accurate detection of TB from tongue swabs (Photo courtesy of Kenny Lass/Tulane University)

Clinical evaluation showed that the new test identified TB from tongue swabs with a 74% detection rate compared to 56% with conventional methods. Sensitivity remained high across other samples: 93% in respiratory fluids, 83% in pediatric stool, and 93% in adult spinal fluid. The study results, published in Nature Communications, demonstrated faster and more accurate detection than standard nucleic acid tests.

By broadening detection to include non-sputum samples, the method could transform TB diagnosis, particularly in low-resource communities where invasive sampling is not feasible. The test allows painless, easily collected swabs and streamlined processing, paving the way for community-based screening. The researchers are also developing portable devices and AI-driven tools to detect drug resistance, paving the way for expanding access, reducing delays, and better connecting patients to effective treatment.

“Tongue swabs are painless, easy to collect, and don’t require trained medical staff,” said lead author Zhen Huang. “That opens the door to large-scale screenings.”

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