A vaccine to prevent UTIs could become a reality if researchers can translate positive results achieved in mice to humans.
If successful, the vaccine has the potential to prevent one of the most common infections affecting women. It is estimated that around half of all women will require treatment for at least one UTI during their lifetime.
Researchers from the University of Michigan screened 5,379 possible bacterial proteins and identified six strong candidates involved in iron uptake to use in a vaccine to prime the body to fight Escherichia coli, the cause of most uncomplicated UTIs.
They tested the vaccine in mice that were given an initial intranasal jab and then booster doses after seven and 14 weeks.
Overall, they found that three proteins (IreA, Hma and LutA) produced significant protection against infection.
The vaccine containing these proteins reduced the number of colony forming units, a measure of bacteria levels, in bladders and kidneys of the mice. The mice were then exposed to infection but were found to be sufficiently protected.
While previous attempts to develop a vaccine for UTIs have failed, the researchers believe that this latest vaccine could work because of its ability to alert the immune system to iron receptors on the surface of bacteria that perform a key function, allowing infection to spread.
The study team, led by Dr Harry Mobley, proposed that by targeting an entire class of molecules involved in iron acquisition instead of a single protein, it was possible to successfully identify components of a protective UTI vaccine.
They added that they had found that strains of E coli taken from women appeared to produce the same iron-related proteins that the vaccine targets, which was an 'encouraging sign' that the vaccine could work against many UTIs in humans.
The researchers are now planning human trials of the vaccine, but warned that it could take several more years for a jab to reach the market.