Biochemical studies on Mycobacterium leprae

Very little information is available on the basic biology of Mycobacterium leprae. It is not known why the organism fails to grow in bacteriological media or in cell cultures and why it has an unusual predilection for certain tissues in the human host where cells derived from the neural crest occur (e.g. skin, peripheral nerves, adrenal medulla). Biochemical studies have revealed that M. leprae contains an unusual form of the enzyme diphenoloxidase which has not been detected in other mycobacteria. The presence of a specific glutamic acid decarboxylase in the organism has been demonstrated. Although a few enzymes of glycolysis and tricarboxylic acid cycle have been investigated, nothing characteristic of the bacterium has been discovered, and how M. leprae derives energy for its survival and proliferation still remains obscure.