It has previously been assumed that bacteria could share their drug-resistant DNA with other bacteria, spreading the resistance and creating more superbugs.
Researchers from the University of Queensland have now discovered how that process works, which gives them a big clue as to how to stop it.
Professor Mark Schembri said the microbes pass DNA to each other through a small “syringe” which also copies the DNA strands.
“Bacteria have their core DNA but they also have what are called plasmids which can contain up to 10, 15 even 20 different genes which code for antibiotic resistance,” he said.
“When the plasmids move from one cell to another they carry all those resistance genes with them.”
Professor Schembri said that had implications for the current method of cycling through antibiotics to avoid resistance.
“If we can detect that a bacteria has resistance to one antibiotic, it’s conceivable they could have maybe 19 more resistances as well, they might have all moved across from another bacteria” he said.
“If you think about an infection, where you’ll have millions and millions of bacteria, only a small number of those might have the resistance genes, but they can very quickly transfer them to all the other bacteria.”
The researchers also identified a gene within bacteria which is used to “turn on” the cellular machinery used to pass on the plasmids, including the microscopic “syringe”.
“We found the 3D structure of the protein which turns on all these resistance genes, and we also uncovered how that protein binds to its target DNA,” Professor Schembri said.
“By understanding that, we now have the opportunity to identify molecules which could block that process.”
Professor Schembri said developing a method along those lines would be key to halting the spread of superbugs into the future.
“These bacteria cause significant infections in humans, like urinary tract infections, respiratory infections, intestinal infections and bloodstream infections which are life threatening,” he said.
“We need to come up with different ways to stop superbugs, and not only does this research provide an opportunity for that, it could help stop this resistance spreading to more bugs which aren’t resistant now.”
The research has been published in the journal Nature Microbiology.
Stuart Layt covers health, science and technology for the Brisbane Times. He was formerly the Queensland political reporter for AAP.