A Tool to Predict Tuberculosis Drug Resistance Now Available Online

Of those approximately 9% have extensively resistant tuberculosis (XDR-TB) where, in addition to resistance to at least both of the major first line drugs (isoniazid and rifampicin), they also have resistance to two classes of second line drugs used to treat MDR-TB (the fluoroquinolones and the injectable drugs, amikacin, kanamycin, or capreomycin).

Current molecular tests examine limited numbers of mutations in Mycobacterium tuberculosis, the organism that causes TB, and although whole genome sequencing could fully characterize drug resistance, the complexity of data obtained by this technology has restricted their clinical application.

To help solve this problem investigators at the London School of Hygiene & Tropical Medicine (United Kingdom) have created an online tool that analyses and interprets genome sequence data to predict resistance to 11 drugs used for the treatment of TB. Initially, a library (1,325 mutations) predictive of drug resistance for 15 anti-tuberculosis drugs was compiled and then validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online "TB-Profiler" tool was developed to report drug resistance and strain-type profiles directly from raw sequences. The TB-Profiler tool is available on the Internet (Please see Related Links below).

Senior author Dr. Taane Clark, reader in genetic epidemiology and statistical genomics at the London School of Hygiene & Tropical Medicine, said, "Sequencing already assists patient management for a number of conditions such as HIV, but now that it is possible to sequence M. tuberculosis from sputum from suspected multi-drug resistance patients means it has a role in the management of tuberculosis. We have developed a prototype to guide treatment of patients with drug resistant disease, where personalized medicine and treatment offers improved rates of cure."

Complete information regarding the new online tool was published in the May 27, 2015, online edition of the journal Genome Medicine.

Related Links:
TB-Profiler tool
London School of Hygiene & Tropical Medicine