Rapid test uses virus that infects bacteria to accurately identify pathogens that cause urinary tract infections
Written by the LabMedica Spanish-language editorial team
Updated on August 1, 2023
About 50 percent of women will be affected by cystitis at some point in their lives, and many of them will experience recurring urinary tract infections. Not only do these bladder infections cause pain and potential complications, but they also pose significant challenges for healthcare providers. The rampant spread of antibiotic resistance in UTIs often forces doctors to prescribe antibiotics indiscriminately, unaware of their efficacy against the pathogens causing the infection. This is largely due to the long time it takes for traditional diagnostic methods to identify a particular pathogen. Now, scientists have developed a rapid test using bacteriophages (viruses that naturally feed on bacteria) and genetically modifying them to further increase their effectiveness at killing pathogenic bacteria.
Phages, or simply phages, are highly specialized viruses. Each phage infects only a specific type or strain of bacteria. Scientists at ETH Zurich (Zurich, Switzerland) have used this unique capability to develop a rapid test and new treatment for urinary tract infections. His first step was to identify the phages that were most effective against the three main types of bacteria associated with UTIs: Escherichia coli , Klebsiella and Enterococcus . The researchers then altered these natural phages to activate the bacteria they recognize and infect by emitting an easily detectable light signal. Using this technique, the researchers were able to reliably identify disease-causing bacteria directly from urine samples within four hours. This new approach could prescribe appropriate antibiotics immediately after diagnosis, minimizing the development of resistance and promoting better antibiotic stewardship.
New rapid test uses bacteriophages to quickly and accurately identify pathogens that cause urinary tract infections (photo courtesy of ETH Zurich)
The new method also has another advantage: It allows doctors to determine which patients might particularly benefit from personalized phage therapy, because the strength of the light signal in the test indicates how well the phages are attacking bacteria: the brighter the sample, the better the response to the treatment. In a proof-of-concept study, the researchers increased the phage’s efficiency by genetically modifying the phage. The altered phage not only produces new phages within the host bacterium, but also produces bacteriocins. These bactericidal proteins are particularly effective against bacterial strains that alter parts of their surface to evade phage recognition, providing a two-pronged attack to enhance therapeutic efficacy.
However, there are still significant hurdles to overcome for the widespread use of this therapy in Western countries. In addition to comprehensive clinical trials, regulatory amendments to consider phages as continuously evolving biological entities that co-evolve with their bacterial hosts would be beneficial. The next step for the researchers will be to test the efficacy of the newly developed phage therapy in clinical trials with selected patients.