Copper could be a secret weapon against antibiotic-resistant UTIs

SCIENTISTS at Texas A&M University are investigating how the immune system uses copper to fight urinary tract infections (UTIs), with the aim of finding new ways to tackle bacteria that resist conventional antibiotics.

The project, led by researchers at the university’s College of Veterinary Medicine and Biomedical Sciences (VMBS), is supported by a $1.48 million grant from the National Institutes of Health (NIH).

It builds on earlier findings by Dr Sarguru Subash, an associate professor in the VMBS Department of Veterinary Pathobiology, whose laboratory discovered that copper levels in the urinary tract rise during infection, helping the body combat invading bacteria.

Copper is essential for human and animal health, but at high concentrations, it becomes toxic to bacteria. The immune system harnesses this property as part of its natural defence against infection.

Specialised immune cells engulf bacteria and expose them to antimicrobial substances, including copper. However, some bacteria have evolved mechanisms to pump out excess copper or otherwise limit its toxic effects, allowing them to survive the immune attack.

The researchers will investigate the genetic mechanisms that enable UTI-causing bacteria to withstand this assault, with the aim of identifying vulnerabilities that could be targeted by new treatments.

“We know that copper plays an important role, but that also raises so many questions about how these pathogens adapt to the presence of increased copper,” Subash said.

Understanding how bacteria overcome copper-based defences could help scientists develop treatments that make the pathogens more vulnerable to the immune system.

READ ALSO: My swollen ankle

The team is also investigating evidence that copper may disrupt fimbriae, tiny hair-like structures that bacteria use to attach themselves to cells lining the bladder.

This attachment helps bacteria establish infections. Without a firm grip on the bladder lining, they are more likely to be flushed out by the natural flow of urine.

Disrupting these structures could, therefore, help control infections, particularly when combined with treatments that kill bacteria directly.

Subash said bacterial defences may become less effective when challenged by the combined action of copper and other immune responses. Whether the body successfully controls an infection or the condition progresses to clinical disease depends partly on which side gains the advantage.

The researchers are also examining ceruloplasmin, a copper-containing protein that may help deliver copper during a UTI.

Because excessive copper can damage healthy cells, the body tightly regulates how it is transported and stored. The team will investigate how ceruloplasmin helps mobilise copper during infection and contributes to controlling bacterial growth.

Subash’s laboratory has also identified an experimental antimicrobial compound that becomes more effective in the presence of copper. Researchers plan to modify and test related compounds to identify promising candidates that can work alongside the immune system.

The strategy combines the direct antibacterial action of potential treatments with the body’s natural defences, offering a possible new approach to tackling antibiotic resistance.

“We are very interested in understanding the basic aspects of how the immune system controls pathogens so we can develop next-generation antimicrobials that not only are focused on directly killing bacteria but also work synergistically with the immune system,” Subash said.

The research could also have applications in veterinary medicine, particularly in addressing recurrent UTIs in dogs. Because some bacteria responsible for UTIs can also infect other parts of the body, the findings may inform future research into other bacterial diseases.