Battling bacteria: UND researchers part of international research effort on drug resistance

GRAND FORKS-The world is at war-and every sneeze, a battleground.Multidrug-resistant bacteria, also known as "superbugs," have taken on an increased focus from medical researchers as older drugs continue to lose their effectiveness in curing disease.
Vials of a solution containing a polymer with potent infection-fighting capabilities are ready for tests at the UND School of Medicine and Health Science. Andrew Haffner / Forum News Service

GRAND FORKS-The world is at war-and every sneeze, a battleground.

Multidrug-resistant bacteria, also known as "superbugs," have taken on an increased focus from medical researchers as older drugs continue to lose their effectiveness in curing disease. If evolution is a fight for survival, then medicine is an arms race between antibiotics and fast-adapting microbes.

A recent international study with research from UND could give us a new molecular weapon that attacks hardy bugs from the outside-in.

Dr. Min Wu studies immune responses as part of the UND School of Medicine and Health Sciences. Both Wu and visiting UND grad student Qinqin Pu are now among nearly 20 scientists who recently authored a paper detailing studies of a biodegradable polymer that appears to destroy drug-resistant bacteria with minimal side effects to the body.

Wu says the study was one of the more logistically complex that he's seen. The polymer inquiry was led by a section of IBM, as well as the bioengineering division of the Singapore-based Agency for Science, Technology and Research.

UND's contributions were in animal testing of the polymer's effectiveness in fighting illness while avoiding damage to healthy tissue. While similar compounds have been developed in the past, the earlier attempts proved toxic to the subjects they were intended to cure.

Wu said the Grand Forks research team put the polymer to work after infecting mice with five types of antibiotic-resistant bacteria commonly known for infecting hospital patients.

That first crew of horribles included E. coli and S. aureus, a skin-related staph infection. Later, researchers exposed mice to peritonitis, an infection of the digestive system, and lung infections known for settling in human patients with breathing catheters.

A panel in the published study shows microscopic images of the invading bacteria before and after treatment with the polymer, which UND researchers injected into the mice. In the first image, the bacteria look smooth and healthy enough. In the second, they are blotched, marked with dark patches and what appear to be holes. With the microbes dead and the infection quashed, the compound itself later passed from the mice with few side effects.

The most clear process at work, Wu said, is the polymer's ability to bind with and open a gap in the cellular surface of the bacteria. The macromolecule is then able to enter the bug and disrupt workings of its cytoplasm, the fluid inside the cell.

Beyond that, Wu says the cell death seems also to be caused by more detailed mechanisms researchers have yet to fully explore. But what they've seen already gives them reason to be optimistic for the polymer's capabilities.

"If a polymer can kill one kind of bacteria, it's no big deal," Wu said, "but this can kill five different kinds."

Those varieties include microbes in both major categories of bacteria, which are differentiated largely by the makeup of their outer layer, or cell wall. The effectiveness of the polymer across diverse organisms indicates it has potential to fight still other kinds of drug-resistant bacteria, including possibly those that have yet to crop up.

Wu thinks the polymer might one day help fight cancer by eradicating malignant cells much as it currently does with microbes.

"We're not stopping here," he said. "We're going to find additional, new weapons-precision medicine requires people to know exactly what's happening in humans and animals when they get infected, and that's what we're trying to learn."