New bacteriophage-based rapid test could identify bacteria causing UTIs within hours

Conventional tests usually determine bacteria causing infection in few days time but new method reliably detects pathogenic bacteria directly from a urine sample in less than four hours
Mrigakshi Dixit
Illustration of Escherichia coli infected by group of phages.
Illustration of Escherichia coli infected by group of phages.

libre de droit/iStock 

Around 1550 BC, the ancient Egyptians provided the first known description of Urinary Tract Infections (UTIs) – "sending forth heat from the bladder" and now the condition has increasingly become common in women and people assigned female at birth (AFAB).

For decades, antibiotics have been widely used to treat and cure urinary tract infections (UTIs), which are bacterial infections that often cause painful urination.

As bacteria appear to be becoming increasingly resistant to antibiotics, scientists are now investigating the viability of bacteriophage-based treatments. Bacteriophages (also known as phages) are small viruses with the ability to naturally destroy a specific bacterium.

Scientists developed a new treatment due to the declining effectiveness of current antibiotic treatments in treating bacterial infections. This reduced success is attributed to the misuse of antibiotics in treating these infections, which in some cases may also lead to recurrent UTIs.

Working to make UTI treatments successful, the ETH Zurich and Balgrist University Hospital team has demonstrated the efficacy of the phage-based test to identify the bacteria causing infection within hours.

According to a study published in 2019, UTIs are the most common outpatient infections, with a lifetime incidence of 50−60 percent in adult women. 

Faster infection detection

UTIs are caused mostly by three kinds of bacteria: Escherichia coli, Klebsiella, and Enterococci. 

It may take a few days for conventional tests to determine which bacteria has caused infection in a particular patient. Doctors prescribe antibiotics to manage the infection for the time being without necessarily knowing how effective they are against the particular bacteria causing the infection.

However, this new test allows for the faster detection of the infection-causing bacteria first, avoiding the need for unnecessary antibiotic use to treat UTIs. 

For this test, the scientists genetically modified phages to allow harmful bacteria to emit light signals. Following this, they were easily able to detect harmful bacteria in urine samples in less than four hours. 

Through this test, doctors would be able to quickly prescribe the right medication to treat an infection caused by a specific bacterium type.

Sniper-like phages  

One of the most significant benefits of phages is that they function like snipers, targeting just specific bacteria. 

To make the most of this feature, the researchers modified the genetic composition of the phages to boost their ability to destroy bacteria. 

The phages were genetically modified in such a way that they not only infected their target but also created additional phages and bacteriocin proteins. These proteins are extremely effective in killing bacteria, especially those that have developed phage resistance. 

“Once they are released, these bacteria-killing proteins are particularly effective against bacterial strains that have altered parts of their surface in such a way that the phages no longer recognize them. This double-barrelled attack makes the treatment more effective,” explained the medical writer, Vanessa Bleich in a statement.