The SigD regulon of Mycobacterium abscessus determines cell envelope composition and antibiotic susceptibility.

The SigD regulon in Mycobacterium abscessus controls cell envelope composition and increases susceptibility to hydrophobic antibiotics, with 447 genes differentially expressed.

• Why it matters: Understanding how M. abscessus regulates its lipid-rich cell envelope is crucial because this structure underpins its high intrinsic resistance to antibiotics, posing a challenge for treatment.
• What they did: Researchers used RNA-Seq and ChIP-Seq to identify SigD target genes, revealing a core set involved in envelope functions, and examined the effects of sigD deletion on envelope composition and drug sensitivity.
• The result: Loss of SigD reduced trehalose polyphleate levels and increased antibiotic susceptibility, highlighting SigD's role in envelope remodeling and stress response, which could inform new therapeutic strategies.