Parashuram Rao1, Kiran Chawla2, Vishnu Prasad Shenoy3, Chiranjay Mukhopadhyay4. 1. Research Fellow, Department of Microbiology, Kasturba Medical College, Manipal, Manipal University, Karnataka 576104, India. 2. Professor and Head, Department of Microbiology, Kasturba Medical College, Manipal, Manipal University, Karnataka 576104, India. Electronic address: arunkiranchawla@yahoo.com. 3. Associate Professor, Department of Microbiology, Kasturba Medical College, Manipal, Manipal University, Karnataka 576104, India. 4. Professor, Department of Microbiology, Kasturba Medical College, Manipal, Manipal University, Karnataka 576104, India.
Abstract
BACKGROUND: Only a few studies done earlier in India reveal the utility of real-time PCR in detecting drug resistance in cases of pulmonary tuberculosis. OBJECTIVES: The study was carried out to standardise real-time PCR (Quantitative real-time PCR, qPCR) targeting 16s RNA for the rapid detection of tuberculosis and its drug resistance from suspected TB patients. MATERIALS AND METHODS: Sputum samples from 100 clinically suspected tuberculosis patients, after processing were subjected to microscopy, MGIT culture and qPCR. qPCR targeted 16sRNA for detecting Mycobacterium tuberculosis complex, KatG and rpoB genes for detection of resistance to isoniazid and rifampicin respectively. 1% proportionate method and Line probe assay (Hain Lifesciences, Nehren, Germany) were used to confirm the MDR isolates. RESULTS: The study showed positivity of microscopy, culture and qPCR for M. tuberculosis as 37%, 44% and 46% respectively. Sensitivity of 100% and specificity of 96.5% in the detection of M. tuberculosis was observed for qPCR in comparison to culture. MDRTB was detected in 14 cases whereas monoresistance to rifampicin and isoniazid was detected in 1 and 3 samples respectively. CONCLUSION: Real-time PCR targeting 16sRNA, KatG and rpoB is a sensitive, specific, rapid and reliable technique to detect pulmonary tuberculosis and its MDR status directly from the sputum samples.
BACKGROUND: Only a few studies done earlier in India reveal the utility of real-time PCR in detecting drug resistance in cases of pulmonary tuberculosis. OBJECTIVES: The study was carried out to standardise real-time PCR (Quantitative real-time PCR, qPCR) targeting 16s RNA for the rapid detection of tuberculosis and its drug resistance from suspected TB patients. MATERIALS AND METHODS: Sputum samples from 100 clinically suspected tuberculosis patients, after processing were subjected to microscopy, MGIT culture and qPCR. qPCR targeted 16sRNA for detecting Mycobacterium tuberculosis complex, KatG and rpoB genes for detection of resistance to isoniazid and rifampicin respectively. 1% proportionate method and Line probe assay (Hain Lifesciences, Nehren, Germany) were used to confirm the MDR isolates. RESULTS: The study showed positivity of microscopy, culture and qPCR for M. tuberculosis as 37%, 44% and 46% respectively. Sensitivity of 100% and specificity of 96.5% in the detection of M. tuberculosis was observed for qPCR in comparison to culture. MDRTB was detected in 14 cases whereas monoresistance to rifampicin and isoniazid was detected in 1 and 3 samples respectively. CONCLUSION: Real-time PCR targeting 16sRNA, KatG and rpoB is a sensitive, specific, rapid and reliable technique to detect pulmonary tuberculosis and its MDR status directly from the sputum samples.
Authors: Kalal Iravathy Goud; Matam Kavitha; Adi Mahalakshmi; Ravi Vempati; Abdulaziz A Alodhayani; Arif A Mohammed; Imran Ali Khan Journal: Afr Health Sci Date: 2020-12 Impact factor: 0.927
Authors: Thales Alves Campelo; Paulo Rafael Cardoso de Sousa; Lucas de Lima Nogueira; Cristiane Cunha Frota; Paulo Renato Zuquim Antas Journal: Access Microbiol Date: 2021-08-02