Abstract
Rapid and accurate detection of drug resistance mutations in Mycobacterium tuberculosis are essential to optimise treatment of tuberculosis and to limit the emergence and spread of drug-resistant strains. The AID TB Resistance line probe assay (Autoimmun Diagnostika GmbH, Strassberg, Germany) is designed to detect the most prevalent mutations that confer resistance to isoniazid, rifampicin, streptomycin, amikacin, capreomycin, fluoroquinolones and ethambutol. This assay detected resistance mutations in clinical M. tuberculosis isolates from low and high endemic areas (Switzerland, n=104, South Africa, n=52) and selected Mycobacterium bovis BCG#1721 mutant strains (n=5) with 100% accuracy. Subsequently, the line probe assay was shown to be capable of rapid genetic assessment of drug resistance in MGIT broth cultures, the results of which were in 100% agreement with that of DNA sequencing and phenotypic drug susceptibility testing (DST).Finally, the line probe assay was assessed for direct screening of smear positive clinical specimens. Screening of 98 clinical specimens demonstrated that the test gave an interpretable result in > 95%. Antibiotic resistance mutations detected in the clinical samples were confirmed by DNA sequencing. We conclude that the TB Resistance line probe assay (AID) is an accurate tool for the rapid detection of resistance mutations in cultured isolates and in smear positive clinical specimens.
Ritter, C