Mycobacterium BCG. (Senior Division).
This research was designed to study the effect of a recombinant
form of Mycobacterium BCG, in which a fluorescent gene has been added to
cultured macrophage and dendritic bone marrow derived cells. Using
sterile technique, a culture titration was performed from stock bacteria
to determine bacteria c.f.u. per ml. Bones removed from pathogenic-free
mice were used to extract bone marrow to obtain base cells that will
then be differentiated into macrophage and dendritic cells. The pure
cultures of immune cells were then infected with the BCG and the
infection rate was determined. Seven days after recombinant BCG
infection, the dendritic and macrophage cells appeared to have engulfed
and lysed the bacterial culture completely, the fluorescent gene having
only been visible within the first three days of infection under a
fluorescent microscope. This proved that after a short amount of time,
the immune system cells were able to engulf and breakdown the
subcellular components of the bacteria.
Erin Pickard, Hi-Plains High School.