The Existence of Mycobacterium tuberculosis in Microenvironment of Bone

Mycobacterium tuberculosis is an obligate aerobe bacteria requiring oxygen in its metabolism. In normal condition, bones have pH of 6.9–7.4 and temperature of 37°C. With the composition mentioned, bones fall in the group of tissue with less rich oxygen (<35%) which theoretically means, M. tuberculosis is hard to grow in the bone environment. Bone microliving environment is formed by the cells constructing the bone itself and the active cells which periodically interact with the bone cells. Activation of these cells gives impact to the temperature, pH, gas concentration, and liquid concentration, and at the same time triggers calcium, phosphor, and other minerals to be deposited in the bone. In the process of new bone formation, the osteoblast cells produce matrix and release them to the microenvironment that needs a high concentration of calcium and phosphor. The survival of M. tuberculosis in the microenvironment of bone is reflected in interaction of the bacteria and the non-immune cells, the bacteria and the organic environment, and the bacteria and the inorganic environment. In addition, the immune system also threatens the survival of M. tuberculosis. The results of these interactions will affect the lives of bacteria and has an impact on the bone microenvironment.