Oxygen Availability and Metabolic Dynamics During Mycobacterium tuberculosis Latency.

Area of Science:

• Microbiology
• Systems Biology
• Computational Biology

Background:

• Oxygen depletion is critical for Mycobacterium tuberculosis (Mtb) nonreplicating persistence (NRP).
• Limited understanding of metabolic differences between slow and rapid oxygen depletion and their impact on Mtb persistence.
• In vitro models suggest oxygen availability significantly influences Mtb persistence.

Purpose of the Study:

• To develop a theoretical model of Mtb metabolic adaptation to varying oxygen depletion rates.
• To investigate the metabolic dynamics enabling persistence during slow versus rapid anaerobiosis.
• To identify metabolic differences correlating with successful versus failed Mtb persistence.

Main Methods:

• Developed a theoretical Mtb metabolic adaptation model incorporating oxygen-driven genetic modulation.
• Included enzymes in the tricarboxylic acid cycle, energy, and redox recycling pathways.
• Conducted in silico studies to analyze Mtb adaptation to slow and rapid anaerobiosis.

Main Results:

• Slow anaerobiosis showed adaptive upregulation of six enzymes during early NRP (NRP1).
• Rapid anaerobiosis showed adaptive downregulation of seven enzymes during active growth.
• Distinct metabolic responses observed between slow and rapid oxygen depletion scenarios.

Conclusions:

• Mtb achieves intricate metabolic balance during anaerobic adaptation.
• Failure in redox recycling is linked to failed Mtb persistence.
• Theoretical description of Mtb metabolic death profile during anaerobic growth provided.