Can Bacteriophages Be Effective Against Certain Antibiotic-Resistant Infections? Study Provide Insights - Video

Researchers have a new battle tactic to fight drug-resistant bacterial infections. Their strategy involves using collections of bacteriophages, and 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 – 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.”

In the new research, Ella Rotman – a scientist in the Mimee Lab – screened wastewater to isolate phages that could effectively kill 27 different Klebsiella strains, including 14 that were newly isolated from University of Chicago patients. The team identified several dozen phages with the capability of killing at least some Klebsiella strains, Then, the researchers analyzed what genetic factors in the bacteria made them most prone to being killed or weakened by each of those phages.

Based on that analysis, Rotman and her colleagues developed a mixture of five phages that each targeted different components of the bacteria. In culture dishes as well as mice, this phage cocktail made antibiotic-resistant Klebsiella bacteria more likely to be attacked by the immune system and, in some cases, more susceptible to treatment with antibiotics. However, in other cases, the bacteria became more antibiotic-resistant after treatment.

By exposing the phage mixture to a series of isolated Klebsiella bacteria, the researchers allowed the phage to evolve. This improved the ability of the cocktail to kill Klebsiella. In mice, the mixture effectively killed or weakened Klebsiella. The researchers observed co-evolution between the bacteria and phage in the mouse intestines, where the Klebsiella evolved to evade phage attack and the phage countered to better infect the altered bacteria.

Reference: “Rapid design of bacteriophage cocktails to suppress the burden and virulence of gutresident carbapenem-resistant Klebsiella pneumoniae,” Rotman et al, Cell Host & Microbe, October 4, 2024. DOI: https://doi.org/10.1016/j.chom.2024.09.004