Streptococcus pyogenes CovRS mediates growth in iron starvation and in the presence of the human cationic antimicrobial peptide LL-37.
Froehlich. Barbara J BJ; Bates. Christopher C; Scott. June R JR
Key Findings
- CovRS enables GAS growth during iron starvation
- CovRS allows GAS to grow in the presence of LL‑37
- CovRS regulates a multimetal transporter operon important for low‑iron conditions
Practical Outcomes
- For biohackers, the takeaway is that LL‑37 isn’t a magic bullet against infections; bacteria have ways to survive it. This limits the peptide’s usefulness as a standalone antimicrobial and suggests you’d need combination strategies or higher doses, which may not be safe or effective.
Summary
The study found that a bacterial control system called CovRS lets group A strep keep growing when iron is scarce and when the human antimicrobial peptide LL‑37 is around, by turning on genes that bring in metals. This means the bacteria can partly resist LL‑37’s killing effect.
Abstract
We found that the global regulatory two-component signal transduction system CovRS mediates the ability of group A streptococcus (GAS) to grow under two stresses encountered during infection: iron starvation and the presence of LL-37. We also showed that CovRS regulates transcription of the multimetal transporter operon that is important for GAS growth in a low concentration of iron.
Study Information
pubmed
2008
2008-11-07T00:00:00.000Z
10.1128/jb.01256-08