Hamilton

McMaster researchers find new antibiotics that kill superbugs 'caught in a cage'

The researchers merged two compounds — the newly-found corbomycin and the lesser-known complestatin — and found they’re able to kill bacteria like the MRSA superbug by catching them ‘in a cage.’

The antibiotics remove bacteria that cause staph infections in a way researchers have never seen before

Researchers from McMaster University merged two compounds — the newly-found corbomycin and the lesser-known complestatin — to examine how they would beat up bacteria and prevent them from growing. Here, a scanning electron microscope (SEM) image shows corbomycin treating Bacillus subtilis. (Submitted by McMaster University, Edited by Christy Groves)

When Beth Culp stared down a microscope in her lab at McMaster University in the summer of 2018, she was "super confused."

After treating a cluster of bacteria cells with antibiotics, she noticed the cells were tangled and twisted. 

That wasn't supposed to happen, but it became a clue that she and her team were on to something.

The 26-year-old PhD biochemistry candidate soon realized they found the opposite of what they were expecting — they discovered a new group of antibiotics that will shock bacteria like the MRSA superbug and snuff out other bacteria that cause infections like staph.

"The drugs we found are active against infections resistant to all these other antibiotics," Culp says.

The researchers merged two compounds — the newly-found corbomycin and the lesser-known complestatin — to examine how they would beat up bacteria and prevent them from growing.

They expected to see the antibiotic compound block the cell wall's construction, foiling bacteria before they even have a chance. 

But what this compound does is sinister. They let the bacteria build a cell wall, but don't let the wall break down again, leaving the bacteria cells trapped and helpless, unable to divide and grow.

"The bacteria are caught in a cage," Culp says.

It's never been seen before in the science community, so it's no surprise the finding was unexpected.

"At the beginning of the project, things didn't really make sense because the patterns we were seeing didn't match anything that anybody had seen before, so nothing made sense, but you start to piece together the clues and figure out the mechanism," Culp says.

"Most antibiotics work only through a handful of mechanisms and no one has really found a new mechanism in decades … it adds to the arsenal of things that will hopefully be available to treat resistant infections."

The team published their findings in the science publication Nature on Wednesday.

For now, Culp and the other researchers are beefing up the antibiotics by modifying some of their molecules' chemical properties.

Once it becomes more of a drug, it'll enter clinics and be the newest weapon against bacteria.

Beth Culp, a 26-year-old PhD candidate in biochemistry and biomedical sciences at McMaster University, says her team's results were the opposite of what they were looking for. (Submitted by McMaster University)

About the Author

Bobby Hristova

Reporter/Editor

Bobby Hristova is a reporter/editor with CBC Hamilton. Email: bobby.hristova@cbc.ca

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