Phage cocktail shows promise against drug-resistant bacteria

Researchers have a new battle tactic to fight drug-resistant bacterial infections. Their strategy involves using collections of bacteriophages, viruses that naturally attack bacteria.

In a new study, researchers at the University of Chicago Pritzker School of Molecular Engineering (PME) and UChicago Medicine have shown that a mixture of these phages can successfully treat antibiotic-resistant Klebsiella pneumoniae infections in mice.

At the same time, however, the team's work revealed just how complex the interactions between phages and bacteria can be; the viruses predicted to be most effective in isolated culture dishes did not always work in animals.

Moreover, both phages and bacteria can evolve over time – in some cases, phages evolved to be more efficient in killing bacteria while in other cases, Klebsiella evolved resistance to the phages.

"We still think phages are an incredibly promising approach to treating drug-resistant bacteria such as Klebsiella," said Mark Mimee, assistant professor of molecular engineering and senior author of the new work, published in Cell Host & Microbe. "But phages are like a living, constantly changing antibiotic which gives them a lot of complexity."

By exposing the phage mixture to a series of isolated Klebsiella bacteria, the researchers gave the phage the opportunity to evolve. This improved the ability of the cocktail to kill Klebsiella. In mice, the mixture effectively killed or weakened Klebsiella.

Image source: UChicago Pritzker School of Molecular Engineering / Jason Smit.