Jpn. J. Infect. Dis., 65 (3), 247-251, 2012

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Aixiao Bi^1,2, Chie Nakajima², Yukari Fukushima², Aki Tamaru³, Isamu Sugawara⁴, Akio Kimura³, Ryuji Kawahara³, Zhongyi Hu¹, and Yasuhiko Suzuki^2,5*

¹Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China; ²Division of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020; ³Department of Infectious Diseases, Osaka Prefectural Institute of Public Health, Osaka 537-0025; ⁴Department of Mycobacterium and Research, Research Institute of Tuberculosis, Tokyo 204-8533; and ⁵JST/JICA-SATREPS, Tokyo 120-8666, Japan

(Received December 6, 2011. Accepted February 29, 2012)

*Corresponding author: Mailing address: Division of Global Epidemiology, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo 001-0020, Japan. Tel: (+81)-11-706-9503, Fax: (+81)11-706-7310, E-mail: このメールアドレスはスパムボットから保護されています。閲覧するにはJavaScriptを有効にする必要があります。

SUMMARY: A rapid, simple, and low-cost diagnostic tool for tuberculosis (TB) detection is urgently needed in countries with a high TB burden. Here, we report a novel loop-mediated isothermal amplification (LAMP) assay targeting the hspX gene for the rapid detection of Mycobacterium tuberculosis, M. bovis, M. africanum, and M. microti. The specificity of this assay was evaluated using 4 reference strains of Mycobacterium tuberculosis complex (MTC), 22 species of non-tuberculous mycobacteria (NTM), 7 non-mycobacterial species, and 50 clinical M. tuberculosis isolates. All the reference MTC strains and M. tuberculosis clinical isolates were successfully detected by this method, and there were no false-positive results with NTM or non-mycobacterial species, which demonstrates the high specificity of this assay for MTC. The detection limit was 10 copies of MTC genome within 27 min, and the detection speed of this assay was higher than that of any other isothermal methods reported so far. Because of its speed, simplicity, sensitivity, specificity, and inexpensiveness, the TB hspX LAMP assay is a potential gene diagnostic method for TB detection in developing countries with a high TB burden.