Y Choi1, S-R Hong2, B-Y Jeon2, H-Y Wang3, G-S Lee2, S-N Cho4, T S Shim5, H Lee2. 1. Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University, Wonju, Korea; Department of Biomedical Laboratory Science, Songho College, Hoengseong-gun, Korea. 2. Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University, Wonju, Korea. 3. M&D Inc, Wonju, Korea. 4. Department of Microbiology, College of Medicine, Yonsei University, Seoul, Korea. 5. Division of Pulmonary and Critical Care Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Abstract
SETTING: Conventional diagnostic methods for tuberculosis (TB) have limited sensitivity and specificity or are time-consuming. OBJECTIVE: 16S rDNA and 16S rRNA of Mycobacterium tuberculosis complex (MTC) were used as targets to develop sensitive and specific polymerase chain reactions (PCRs) to improve the diagnosis of MTC. DESIGN: We developed conventional and real-time PCRs targeting 16S rDNA and rRNA of MTC. RESULTS: PCRs targeting 16S rRNA had a 10-100 times lower limit of detection for M. tuberculosis than PCRs targeting 16S rDNA. The sensitivities of the 16S rDNA PCR, 16S rRNA reverse transcription PCR (RT-PCR), 16S rDNA real-time PCR and 16S rRNA real-time RT-PCR for sputum specimens were respectively 92%, 94.6%, 96% and 100%. Real-time PCR showed no cross-reactivity, but conventional PCR had cross-reactivity to M. avium, M. gastri and M. nonchromogenicum. CONCLUSION: PCRs targeting the 16S rRNA of MTC were more sensitive than those targeting 16S rDNA; 16S rRNA real-time RT-PCR showed the highest sensitivity and specificity for MTC.
SETTING: Conventional diagnostic methods for tuberculosis (TB) have limited sensitivity and specificity or are time-consuming. OBJECTIVE: 16S rDNA and 16S rRNA of Mycobacterium tuberculosis complex (MTC) were used as targets to develop sensitive and specific polymerase chain reactions (PCRs) to improve the diagnosis of MTC. DESIGN: We developed conventional and real-time PCRs targeting 16S rDNA and rRNA of MTC. RESULTS: PCRs targeting 16S rRNA had a 10-100 times lower limit of detection for M. tuberculosis than PCRs targeting 16S rDNA. The sensitivities of the 16S rDNA PCR, 16S rRNA reverse transcription PCR (RT-PCR), 16S rDNA real-time PCR and 16S rRNA real-time RT-PCR for sputum specimens were respectively 92%, 94.6%, 96% and 100%. Real-time PCR showed no cross-reactivity, but conventional PCR had cross-reactivity to M. avium, M. gastri and M. nonchromogenicum. CONCLUSION: PCRs targeting the 16S rRNA of MTC were more sensitive than those targeting 16S rDNA; 16S rRNA real-time RT-PCR showed the highest sensitivity and specificity for MTC.