Md. Shahedur Rahman Khan1, Md. Abu Raihan1, Md Ziaul Karim2, Md Abdur Rouf1,Bashir Ahmed1, Md Khairul Hassan Jessy1, Biwas Akhtar Hossain1,Mahmud Rahim2 Shamim Ahmed3, Jibesh Kumar Pramanik4 Md. Meer Mahbubul Alam5, Barkat Ullah2, Farhana Islam6
Abstract:
Globally, there are 8 million new Mycobacterium tuberculosis (TB) cases
and 2 million deaths per year.1Once infected, most individuals enter into a
state of latency with no clinical manifestations and are not contagious. This
state can reactivate at a later stage, particularly if the individual becomes
immunocompromised. However, the remaining individuals develop an active
infectious disease. Given the infectious nature of TB, accurate and early
diagnosis is a critical step in its management and control. 2 Overall, the
accuracy of nucleic acid based tests have been shown to be far superior when
applied to respiratory samples as opposed to other body fluids. 3 The processing
of clinical specimens in the mycobacterial diagnostic laboratory has undergone
remarkable improvements during the last decade. While microscopy and
culture are still the major backbone for laboratory diagnosis of tuberculosis
on a worldwide basis, new methods including molecular diagnostic tests
have evolved over the last two decades. The majority of molecular tests have
been focused on (i) detection of nucleic acids, both DNA and RNA, that are
specific to Mycobacterium tuberculosis, by amplification techniques such as
polymerase chain reaction (PCR); and (ii) detection of mutations in the genes
that are associated with resistance to antituberculosis drugs by sequencing
or nucleic acid hybridization. 4 Recent developments in direct and rapid
detection of mycobacteria, with emphasis on M. tuberculosis species
identification by 16S rRNA gene sequence analysis or oligohybridization and
strain typing, as well as detection of drug susceptibility patterns, all contribute
to these advances.4 Generally, the balance between genome instability and
genome maintenance as the basis for evolutionary development, strain
diversification and resistance development is important, because it cradles
the resulting M. tuberculosis phenotype. Molecular methods present many
advantages compared with conventional diagnostics. Results are quick,
reliable and reproducible,and even mixed cultures can be analyzed. DNA