Rapid detection of Mycobacterium tuberculosis complex in sputum Samples using PURE TB-LAMP assay

The detection and diagnosis of tuberculosis (TB) in food-producing animals is critical to human health. In this study we applied the loop-mediated isothermal amplification (LAMP) system to detect Mycobacterium tuberculosis complex (MTC) directly in 57 cattle and six lechwe (Kobus leche kafuensis) carcasses exhibiting lesions characteristic of TB. The samples were first subjected to Ziehl-Neelsen microscopy, followed by culture and LAMP assay. In addition, multiplex-PCR was used to determine the species involved. Of the samples from the cattle, 84.2% (95% confidence interval: 71.6-92.1) were found positive with Ziehl-Neelsen microscopy, 93.0% (95% confidence interval: 82.2-97.7) with culture, and 94.7% (95% confidence interval: 84.5-98.6) with the LAMP system while the Kobus leche kafuensis samples were all positive for all techniques used. These results indicate that the LAMP system can be used to augment the detection and surveillance of TB in animals; hence can be a very useful tool in the veterinary field and in public health.

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1633. Improving the diagnosis of extra-pulmonary tuberculosis (EPTB): experience from north India

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.1813 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S808-S808

Author(s):

Anchal Sharma ◽

Kusum Sharma ◽

Manish Modi ◽

Aman Sharma

Keyword(s):

Mycobacterium Tuberculosis ◽

Pulmonary Tuberculosis ◽

Mycobacterium Tuberculosis Complex ◽

Lamp Assay ◽

Nucleic Acid Amplification ◽

Rural Setting ◽

Tuberculosis Complex ◽

Extra Pulmonary Tuberculosis ◽

Resource Poor ◽

Extra Pulmonary

Abstract Background Rapid and accurate diagnosis of extra-pulmonary tuberculosis (EPTB) is imperative for early treatment and better patient outcome. Loop-mediated Isothermal Amplification (LAMP) is a promising nucleic-acid amplification assay. LAMP assay could be carried out in simple water bath under isothermal conditions in 60 minutes, and can be performed in any laboratory even in rural setting in resource poor endemic countries. We evaluated LAMP assay using two different target regions LAMP primers specific for Mycobacterium tuberculosis complex for the diagnosis of EPTB. Methods LAMP assay using 6 primers (each for IS6110 and IS1081) specific for Mycobacterium tuberculosis complex were performed on patients suspected of EPTB on various EPTB samples(CSF, Synovial fluid, Lymaphnode and tissue biopsies and various other samples) of 150 patients (50 confirmed, 100 suspected) Clinically suspected of EPTB and 100 non-TB control subjects. Results Overall LAMP test (using any of the two targets) had sensitivity and specificity of 96% and 100% for confirmed (50 culture positive) EPTB cases. In 100 clinically suspected but unconfirmed EPTB cases, LAMP was positive in 87 out of 100 cases (87%). Sensitivity of IS6110 LAMP, 1S1081 LAMP and IS6110 PCR for clinically suspected cases was 78 (78%), 84 (84%) and 70 (70%), respectively. In total 150 EPTB patients, the overall sensitivity of microscopy, culture, IS6110 PCR, IS6110 LAMP, 1081 LAMP and the LAMP test (if any of the two targets were used) were 4%, 33.3%, 74.6%, 82.66%, 87% and 92%, respectively. Specificity of all the tests was 100%. There were 8 cases which were missed by IS6110 LAMP and 2 cases by 1081 LAMP. Conclusion LAMP assay using two targets is a promising technique for rapid diagnosis of EPTB in 60 minutes especially in a resource poor setting who are still battling with this deadly disease. Disclosures All Authors: No reported disclosures

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