Mycobacterium tuberculosis, the causative agent
of tuberculosis has made a huge impact on public health killing over 1.5
million people each year. More than 95% of deaths occurr in developing countries, and in country like India,
China, Indonesia, Pakistan and the Philippines more than 50% death occurs. Human
is the only known species to be affected by M.
Tuberculosis. The bacterium enters the body by inhalation of very small aerosols
from infected persons. It is a slow-growing bacteria that requires lot of
oxygen and blood. That’s why it is mostly found in the lungs. The
bacterium might grow immediately causing primary tuberculosis or the bacilli
may become dormant and affect at later stages called as latent tuberculosis. Diagnosing
active tuberculosis is very difficult as is like diagnosing the disease in
The gene expression in M.
Tuberculosis is tuned to
adapt to the host environment, including hypoxia, nutrient deprivation, low pH,
and maintain these adaptations over a long period of time. This way they have
evolved the ability to survive and persist for decades in the harsh environment
inside its human host (Shell et al., 2013).
tuberculosis complex (MTBC) is M.
africanum, M. bovis, M. canettii
and M. Microti bacteria referred
together . Strains of M. tuberculosis complex with
characteristics between M. tuberculosis
and M. bovis have been assigned to M. africanum. It is observed that
factors such as polymorphism have a great value in human colonization,
infectivity, and virulence among these M.
tuberculosis genotype (Fleischmann et al., 2002; van Soolingen et al., 1997)
The genome of M. tuberculosis are
generally studied using the strain M. tuberculosis H37Rv. The genome
contains about 4000 genes (Cole, 2002). The species of the Mycobacterium tuberculosis complex show a 95-100% DNA
relatedness concluded by sequence of the 16S rRNA gene which are exactly the
same for all the species (Aranaz et al.,