| dc.description.abstract | Mycobacterium tuberculosis, a global health problem, affects millions of people
each year. Tuberculosis is a common infectious disease in developing countries
that requires rapid and accurate diagnosis. In order to standardize the quality of
the diagnostic procedure for tuberculosis-controlling programs, developing high quality mock sputum samples for use in External Quality Assessment programs in
clinical laboratories is of great importance. That helps quality control centers
evaluate the activities of laboratory systems dedicated to the National Program of
Tuberculosis Control with a strong emphasis on molecular diagnostic procedures,
which are currently the recommended first-line tuberculosis detecting tests. In this
project, we formulated a workflow for the development of an in-house mock
sputum sample containing Mycobacterium tuberculosis samples and assessed
some pilot quality control of the product. In brief, Mycobacterium tuberculosis was
inactivated by boiling. Next, the bacterial concentration was determined by
McFarland turbidity and confirmed using Real-time PCR, aiming for a cycle
threshold value of around 24. Then, polymorphonuclear leukocytes, epithelial
cells, egg whites, and the positive tuberculosis samples were mixed and
lyophilized. After that, the efficacy of Real-time PCR from mock sputum samples
was tested using a primer pair for the IS6110 element, which is present in most
Mycobacterium tuberculosis complex strains and provides higher sensitivity for
bacterial detection. The Real-time PCR showed good results, with the cycle
threshold for detection of the sequence target using SYBR green dye at around
24. The cycle threshold values and the amplification efficiency suggest that the
lyophilized sputum mock samples can be effectively used in External Quality
Assessment programs, helping clinical laboratories test the accuracy of
tuberculosis diagnostic procedures. | en_US |
