Zinc may help as a non-antibiotic treatment for urinary tract infections

New details on the role of zinc in our immune system could help develop new non-antibiotic treatment strategies for bacterial diseases, such as urinary tract infections (UTIs).

Urinary tract infections are one of the most common bacterial infections in the world, with about 150 million cases a year, and can lead to serious conditions such as kidney infection and sepsis.

A team of interinstitutional researchers from the University of Queensland, led by professors Matt Sweet, Mark Schembri and Ronan Kapetanovic, examined how our immune system uses zinc to fight uropathogens. Escherichia coli (UPEC) – the leading cause of urinary tract infections.

Dr. Kapetanovic, of the Institute of Molecular Biosciences (IMB) of the UQ, said that researchers already knew that zinc was toxic to bacteria.

"We have confirmed by direct visualization that the cells in our immune system called macrophages use zinc to eliminate bacterial infections," said Dr. Kapetanovic.

They also discovered that the UPEC had a two-pronged strategy for surviving the body's immune response.

"We found that, compared with non-pathogenic bacteria, UPEC can escape the macrophage response to zinc toxicity, but that these bacteria also exhibit increased resistance to the toxic effects of zinc.

"These findings give us clues as to how our immune system fights infections, as well as on potential developmental pathways for treatments, such as blocking UPEC leakage of zinc to make it more sensitive to this metal.

"Treatment strategies that do not use antibiotics have the advantage that bacteria do not develop resistance. If we could reprogram our immune cells to strengthen them, or change the way they react." to bacteria, we would be better equipped to fight superbugs "

The UQ's School of Chemistry and Molecular Bioscience, Minh Duy Phan, said the study had also made it possible to identify all of the UPEC genes offering protection against the toxicity of zinc.

"This knowledge is another way to develop antimicrobial agents for the treatment of urinary tract infections," said Dr. Phan.

IMB PhD Miss Claudia Stocks, a student, said that the methods used by the team could be applied to the study of other bacterial diseases, not just urinary tract infections.

Macrophages exhibit zinc toxicity against several types of bacteria, such as Mycobacterium tuberculosis, Salmonella and Streptococcus, which are not necessarily removed from the body by normal mechanisms, "said Miss Stocks.

"We have developed zinc sensors that can be adapted to study different types of bacteria, which allows us to better understand our immune system and create therapies for a range of infectious diseases."

The search was published in Proceedings of the National Academy of Sciences.

Provided by
University of Queensland