As antibiotic resistance becomes a growing concern, scientists are exploring alternative ways to fight infections, including the use of copper. Researchers at the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) are studying how the body uses copper to combat urinary tract infections (UTIs), how bacteria survive exposure to copper, and whether these findings could lead to new treatment strategies. Previous research from the lab of Dr. Sarguru Subash, an associate professor in the VMBS Department of Veterinary Pathobiology, has shown that the body increases copper levels in the urine during infection to kill bacteria that cause UTIs. Subash explained that while copper plays a key role in the immune response, it also raises questions about how bacteria adapt to higher copper levels in the body. Copper is an essential nutrient for both humans and animals, but it can be toxic to bacteria when present in the right environment and concentration. The immune system uses this property during infection by having specialized cells engulf bacteria and expose them to an antimicrobial mixture that includes copper. However, during a UTI, bacteria have evolved mechanisms to remove or detoxify copper, allowing them to survive and multiply. Subash noted that while bacteria have these defenses, they are less effective when exposed to copper in combination with other antimicrobial components of the immune system. This creates a kind of "tug-of-war" where the immune system can sometimes control bacterial growth before illness occurs, but at other times, bacteria overcome these defenses and cause disease. Subash’s new research project will examine this interaction from both sides—how the body uses copper to fight infection and how bacteria respond to it. The team will investigate the genetic mechanisms that allow UTI-causing bacteria to tolerate increased copper levels and continue growing despite the immune system's attempts to stop them. They will also explore early evidence suggesting that copper may interfere with fimbriae, hairlike structures on bacteria that help them attach to the lining of the bladder. Bacteria that cannot attach firmly to the bladder are more likely to be flushed out of the body. The researchers will also study ceruloplasmin, a copper-containing protein that may help deliver copper during a UTI. The body carefully regulates the transport and storage of metals like copper to prevent damage to its own cells. Subash’s team will investigate how ceruloplasmin helps mobilize copper during infection and how this process contributes to the immune system’s ability to control invading bacteria. The studies aim to better understand the complex interaction between the body’s defenses and disease-causing organisms. The ultimate goal of the research is to develop new treatments based on this knowledge. The team previously discovered an experimental antimicrobial compound that becomes more effective in the presence of copper, and they will now modify and test related compounds to identify potential candidates for future therapies that could work alongside the immune system’s natural defenses. While any copper-based treatment for UTIs is likely years away from being available to the public, this research could provide an important early step in developing new options for infections that are difficult to treat. Although the study is focused on UTIs, its findings may have broader implications, as some of the same bacteria that cause UTIs can also cause infections in other parts of the body. The research could also be valuable in veterinary medicine, where UTIs are a common issue in animals like dogs. For now, Subash and his team are focused on understanding the fundamental relationship between the body’s copper defenses and the bacteria that try to overcome them.