PT - JOURNAL ARTICLE AU - Ehsan Aryan AU - Zahra Meshkat AU - Seyedeh-Zohreh Mirbagheri AU - Amir-Hooshang Alvandi AU - Hadi Safdari AU - Bamdad Riahi AU - Mastoureh Momen-Heravi TI - Improved detection of mycobacterium tuberculosis using an inhibitor-tolerant loop-mediated isothermal amplification DP - 2014 Sep 01 TA - European Respiratory Journal PG - P2588 VI - 44 IP - Suppl 58 4099 - http://erj.ersjournals.com/content/44/Suppl_58/P2588.short 4100 - http://erj.ersjournals.com/content/44/Suppl_58/P2588.full SO - Eur Respir J2014 Sep 01; 44 AB - Conventional methods remain as the cornerstone of laboratory diagnosis of tuberculosis (TB). However, certain drawbacks of these approaches have attracted attentions to the development of newer molecular methods for detection of Mycobacterium tuberculosis (Mtb). To reliably detect Mtb in clinical specimens, we developed a loop-mediated isothermal amplification (LAMP) reaction targeting mpt64, a gene presents in all strains of Mtb, and the results were compared with mpt64-nested PCR (nPCR). Eighty five out of 189 clinical specimens evaluated in this cross-section study were rule out to have TB and they were used to calculate the specificity of the reactions that was 89.4% (76/85, 95% confidence interval [CI], 81-95%) and 84.7% (72/85, CI, 75.3-92%) respectively for nPCR and LAMP. Although the analytical sensitivity of nPCR was 1000-fold greater than the one obtained by the LAMP, the overall diagnostic sensitivity of LAMP (84.6% [88/104], CI, 76.2-91%) was higher than the one of nPCR (71.2% [74/104], CI, 62-80%). Interestingly, further analysis showed that 90% (27/30) of false-negative nPCR results were due to the presence of inhibitors in clinical specimens, while 77.8% (21/27) of these specimens were positive by the LAMP.Accordingly, significant higher tolerance of LAMP to inhibitors than that of nPCR (p<0.0001) leads to improved detection of Mtb using this new generation of gene amplification method. Moreover, lack of popular genes such as IS6110 in some strains of Mtb poses mpt64 as a more reliable target.