Discover how the humble bacterium E. coli uses hydrogen sulfide to enhance its iron uptake and bolster its defenses against antibiotics, shedding light on a crucial survival mechanism.
The Strange Superpower of Hydrogen Sulfide
In the bacterial world hydrogen sulfide (H2S), though often tipped as a villain due to its putrefying odor of rotten eggs, is the chemical Superman. This molecule is a small one that participates in chemical signaling to turn on or off a multitude of processes inside the bacterium, from responses to oxidative stress and antibiotics.
Hydrogen sulfide is already known to serve as an essential signal in the pathogenic bacterium Vibrio cholerae, where it stimulates increased iron acquisition and resistance to oxidative stress. In Escherichjson coli (E. coli), a ubiquitous bacterium, the exact nature of these effects has been difficult to define, though — that is until now.
The Mystery of E. coli
Supported by a team of scientists from Tokyo Tech, Professor Shinji Masuda sought to determine how H2S levels inside E. coli might influence its ability to take up iron.
They employed a dual-strategy; they first overexpressed the enzyme 3-mercaptopyruvate sulfur transferase (mstA) that is responsible for producing H2S by genetic manipulation in wild-type E. coli strain followed by/Lactate treatment. This strategy compensated for the increased endogenous H2S levels present intracellularly, enabling them to pinpoint which cellular processes of the bacterium would be affected by elevated levels of intracellular H2S.
The researchers then used sophisticated genetic sequencing and assays to determine which molecular pathways were responsible for the regulation of iron uptake under these conditions influenced by H2S availability. Their results, which have been published in the prestigious journal mBio, provide new information on how humble hydrogen interacts with the roulette tactics used by this bacterium to help it survive.
Conclusion
Professor Masuda’s research has revealed the critical importance of hydrogen sulfide in iron uptake and stress response (Masuda et al sitting masuda E-JOC reference info author). Their work further begins to unmask the molecular gears in this deadly gonorrhea clock, which could open new routes to fight other antibiotic-resistant strains of the bug. In a world still wrestling with the global epidemic of antimicrobial resistance, this is potentially positive news suggesting we might one day outsmart these stubborn germs.
