This document summarizes a study evaluating a rapid molecular test called Xpert MTB/RIF for detecting Mycobacterium tuberculosis (MTB) and resistance to rifampin directly from sputum samples. Three sputum specimens from patients were tested with the Xpert MTB/RIF assay, which can detect MTB and rifampin resistance from untreated sputum in under 2 hours. The results showed the Xpert MTB/RIF test provided sensitive detection of tuberculosis and rifampin resistance directly from sputum with minimal hands-on time.

1. Rapid Molecular Detection of
Tuberculosis and Rifampin
Resistance.
Presented By : Khaled Alkhodari
Supervised By :Dr. saeb aliwaini
Due to : 26/11/2014

2. Outline
I. Introduction.
II. Methods.
III. Results.
IV. Conclusion.
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3. Introduction
 Tuberculosis (TB): is a bacterial infection that can spread through the lymph
nodes and bloodstream to any organ in the body. It is most often found in the
lungs.
 Rifampin : is a drug used to treat TB
 inhibits bacterial RNA polymerase.
 Bacterial resistance to it is caused by mutations in rpoB gene leading to a change
in the structure of the β subunit of RNA polymerase.
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4. Methods
 Xpert MTB/RIF : an automated molecular test for Mycobacterium
tuberculosis(MTB) and resistance to rifampin (RIF).
 Three sputum specimens:
 Two specimens were processed with:
 N-acetyl-l-cysteine ( NALC ) and sodium hydroxide (NaOH ) before microscopy, solid and
liquid culture.
 The MTB/RIF test.
 One specimen was used for direct testing with microscopy and the MTB/RIF test.
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5. Xpert MTB/RIF Test
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an automated molecular test for
Mycobacterium tuberculosis(MTB) and
resistance to rifampin (RIF),
polymerasechain-reaction (PCR) assay to
amplify an MTB specific sequence of the
rpoB gene , gene encodes the β subunit of
bacterial RNA-polymerase.

6. 6
(Fig. 1)

7. 7
Results
(Fig. 1 Cont’d)

8. 8

9. 9

10. 10

11. Conclusion
 The MTB/RIF test provided sensitive detection of tuberculosis and rifampin
resistance directly from untreated sputum in less than 2 hours with minimal
hands-on time.
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13. The authors
 Catharina C. Boehme, M.D., Pamela Nabeta, M.D., Doris Hillemann, Ph.D.,
Mark P. Nicol, Ph.D.,
Shubhada Shenai, Ph.D., Fiorella Krapp, M.D., Jenny Allen, B.Tech., Rasim
Tahirli, M.D., Robert Blakemore, B.S.,
Roxana Rustomjee, M.D., Ph.D., Ana Milovic, M.S., Martin Jones, Ph.D., Sean
M. O’Brien, Ph.D.,
David H. Persing, M.D., Ph.D., Sabine Ruesch-Gerdes, M.D., Eduardo Gotuzzo,
M.D., Camilla Rodrigues, M.D.,
David Alland, M.D., and Mark D. Perkins, M.D.
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