# Pulcherriminic acid relay; a Bacilli route to attack pathogens

## TL;DR

Bacillus subtilis uses pulcherriminic acid to deprive pathogens like Staphylococcus aureus of iron, potentially offering a new way to combat drug-resistant infections.

## Contribution

This paper explores the novel PA relay mechanism and its impact on the iron regulation system in Staphylococcus aureus.

## Key findings

- Pulcherriminic acid interacts with free iron to form pulcherimin, which accumulates on pathogens.
- The PA relay mechanism disrupts the iron homeostasis and virulence in Staphylococcus aureus.
- PA-producing Bacillus species show promise in mitigating drug-resistant S. aureus infections.

## Abstract

Pulcherriminic acid (PA) relay is a recently discovered phenomenon in which the Bacillus subtilis employs branching biofilms to relay the antimicrobial pigment, pulcherriminic acid towards the pathogen. PA interacts with the free iron in the environment to form the reddish-pink pigment, pulcherimin, which subsequently accumulates on the pathogen depriving them of the essential iron. In Staphylococcus aureus, the ferric uptake regulator (Fur) system plays a vital role in maintaining iron homeostasis, virulence, and biofilm formation. The perspective article discusses the plausible mechanistic insights on the impact of PA relay in hampering the Fur system. Taken together, these findings highlight PA and PA-producing Bacillus species as a promising alternative for mitigating drug resistant S. aureus infections.