Chloramphenicol-mobilized Bacillus subtilis transiently expresses resistance to multiple antibiotics, including the glycopeptides phleomycin and bleomycin.

Chloramphenicol exposure induces transient, spatiotemporal expression of multiple antibiotic resistance genes in Bacillus subtilis colonies, including novel resistance to glycopeptides phleomycin and bleomycin.

• Why it matters: Understanding how antibiotics influence bacterial gene regulation and community dynamics is crucial for addressing the global crisis of antibiotic resistance and preventing its spread.
• What they did: Researchers used luciferase reporter constructs to analyze resistance gene expression patterns in B. subtilis colonies exposed to subinhibitory chloramphenicol, revealing regulation via transcription attenuation and endogenous translation pausing.
• The result: Pre-exposure to chloramphenicol improved B. subtilis growth under subinhibitory glycopeptide concentrations, and BmrCD was shown to confer resistance to phleomycin and bleomycin, extending resistance beyond translation-targeting drugs.