MOB rules: Antibiotic Exposure Reprograms Metabolism to Mobilize Bacillus subtilis in Competitive Interactions

Area of Science:

• Microbiology
• Bacterial Physiology
• Systems Biology

Background:

• Antibiotics exhibit dose-dependent effects, with subinhibitory concentrations triggering varied bacterial responses.
• Bacillus subtilis mobilizes via a population-spreading mechanism when exposed to bacteriostatic translation inhibitors.
• The regulatory mechanisms governing antibiotic-induced bacterial mobilization remain largely unknown.

Approach:

• Investigated the regulatory functions essential for Bacillus subtilis mobilization under subinhibitory chloramphenicol exposure.
• Analyzed changes in gene expression and metabolism, mapping them to a regulatory protein network.
• Utilized reporter genes for pdhA and pucA to visualize metabolic compartmentalization within the mobilized population.

Key Points:

• Several transcriptional regulators coordinate metabolic reprogramming, including glycolysis, nucleotide, and amino acid metabolism, to support bacterial mobilization.
• Identified pdhA and pucA gene expression and metabolite abundance as key indicators of mobilized population metabolic states.
• Demonstrated that Bacillus subtilis mounts a coordinated mobile response through a regulated metabolic adaptation to chloramphenicol.

Conclusions:

• Uncovered a network of transcriptional regulators controlling metabolic shifts crucial for Bacillus subtilis population mobilization.
• Highlighted the distinct metabolic profiles within different regions of the mobilized bacterial population.
• Revealed a regulated, population-level response enabling coordinated movement and adaptation to subinhibitory antibiotic stress.