Studies will be carried out with inocula of Mycobacterium leprae, freshly harvested, from the infected foot pads of nu/nu mice and enriched for viable organisms, to explore optimal biophysical and nutritional parameters for the metabolic maintenance of the leprosy bacillus using the following combination of sensitive metabolic assays: a) quantitation of intracellular adenosine triphosphate (ATP), b) incorporation of 14C-palmitate into PGL-1, c) measurement of the rate of 14CO2 released from 14C- palmitate. The combined use of these indicators of net energy status, anabolic and catabolic activity will overcome the limitations inherent in using a single metabolic assay. Preliminary studies indicate an acidic pH optimum (5.5-6.5) and a requirement for continuous maintenance of a gaseous environment with an oxygen concentration below ambient (2.5-10%) Metabolic maintenance and in vitro drug susceptibility testing under these conditions are markedly superior to closed systems employing neutral pH. This approach should lead to the step-wise development of a medium which will support long-term maintenance and subsequently genuine growth of M. leprae. Less than total success should still allow significant improvement in an in vitro medium in which drug activity against M. leprae could be assessed via changes in metabolic activity.
|Franzblau, S G; Biswas, A N; Harris, E B (1992) Fusidic acid is highly active against extracellular and intracellular Mycobacterium leprae. Antimicrob Agents Chemother 36:92-4|
|Franzblau, S G (1991) In vitro activities of aminoglycosides, lincosamides, and rifamycins against Mycobacterium leprae. Antimicrob Agents Chemother 35:1232-4|
|Franzblau, S G; White, K E (1990) Comparative in vitro activities of 20 fluoroquinolones against Mycobacterium leprae. Antimicrob Agents Chemother 34:229-31|
|Ramasesh, N; Krahenbuhl, J L; Hastings, R C (1989) In vitro effects of antimicrobial agents on Mycobacterium leprae in mouse peritoneal macrophages. Antimicrob Agents Chemother 33:657-62|
|Franzblau, S G; White, K E; O'Sullivan, J F (1989) Structure-activity relationships of tetramethylpiperidine-substituted phenazines against Mycobacterium leprae in vitro. Antimicrob Agents Chemother 33:2004-5|
|Franzblau, S G (1989) Drug susceptibility testing of Mycobacterium leprae in the BACTEC 460 system. Antimicrob Agents Chemother 33:2115-7|