The Hunt for Stronger Antibiotics

Mike sits in his doctor's office during a follow-up visit for a lingering bacterial infection that is threatening his health. As he sits on the examination table, his doctor discusses options with him. 

"This is a tricky infection. There's one more antibiotic we can try." 

"Why aren't there more drug options?" Mike asks, confused. 

"Bacteria adapt quickly to existing drugs, but LSU researchers are now exploring ways to kill bacteria by starving them of iron."  

Mike's doctor paints a picture of researchers at work in the lab, trying to find new ways to interfere with important molecular pathways in bacteria that rely on iron.  

Mike imagines little red blood cells coursing through his blood vessels, holding armfuls of yellow iron particles. He imagines evil little green bacteria coming in to steal that iron... 

“Wait, I thought my blood cells needed that? It's in my multivitamins!" Mike says. 

“All living things need iron! But in just the right amount…" 

Mike's doctor explains bacteria's need for iron as a Goldilocks and the Three Bears situation... too much iron is poisonous ("Ack, too much!" the bacteria says...), but too little can also harm the bacteria... 

“LSU researchers are studying how bacteria monitor and regulate their iron levels…" Mike's doctor explains. 

While Mike's immune cells are busy protecting the iron in his body from bacterial thieves, the microbes that are causing his infection have a back-up plan: iron in storage. They can sense when their iron levels are low thanks to a sensitive iron-sensing pathway. The pathway involves a protein called ferredoxin that is activated by a signaling iron-sulfur cluster. “I’m running low! This man’s immune cells are hogging all the iron!” the microbe says. "Go get your own!" the immune cell yells back. 

An active ferredoxin helps to release iron particles normally stored in a large round container protein called bacterioferritin. A drug that interferes with this release of stored iron could kill the bad bacteria in Mike's body, helping his immune cells win their fight. "LSU researchers are also studying how a new drug that locks iron in storage can kill biofilm bacteria," the doctor says. Mike imagines a sick bacterium with bloodshot eyes, sighing, "UGHHH! I don't feel good..." A new type of antibiotic could prevent ferredoxin and bacterioferritin from interacting, trapping iron inside its storage container and tricking bacteria into thinking they have no iron available. 

"Stand back! Nothing to see here." 

Mike feels hopeful that this new potential type of antibiotic could one day help people like him who have difficult-to-treat bacterial infections. 

Research saves lives!