Researchers at the University of Bath have developed a new catheter coating that changes the colour of the urine in response to growing bacterial numbers. The infection alert system – which was described in the journal, Biosensors and Bioelectronics – could prevent serious infections in the millions of patients who use catheters worldwide.
Catheters are used to drain urine from incontinent patients, or those recovering from a medical procedure. Used in both hospitals and long-term care homes, catheters can sometimes cause problematic infections. In the US alone, hospital-acquired urinary infections affect over 90,000 individuals each year, according to the Centers for Disease Control and Prevention (CDC).
In an effort to catch these urinary infections early, Dr. Toby Jenkins and his team from the University of Bath, designed an easy colorimetric warning system. “Catheter-related infections are a serious problem, especially if the bacteria are resistant to antibiotics,” said Jenkins. “We hope that with this simple to use sensor system we can ultimately make a real difference to patients’ lives.”
Bacteria present inside the catheter tube can produce a biofilm, which could block the catheter over time. Since urine can’t be drained through a blocked catheter, it is pushed back into the kidneys where the bacteria can proliferate.
This type of kidney infection can lead to organ failure, sepsis, or death. Though nearly 50 percent of people who rely on catheters will experience bacterial blockage issues, there has never before been a way to detect blockages before they lead to an infection.
The coating developed by Jenkins and his colleagues can detect biofilms produced by the bacterial species, Proteus mirabilis. The infection alert system is able to alert caregivers of potential blockages a full 10 to 12 hours before they are fully formed.
In developing the system, Jenkins and his lab used a glass bladder filled with artificial urine and introduced patient-derived bacterial samples into the system. The byproducts of bacterial growth serve to turn the urine more alkaline in pH, which releases a bright yellow dye from the catheter coating.
“Our new coating works with existing catheter designs and gives a clear, early visual warning of infection before a catheter is blocked,” said Jenkins. “It could dramatically reduce the number of infections resulting from bacterial blockages.”
As biofilm-based infections are difficult to treat, the researchers hope their alert system could reduce the occurrence of catheter blockages, thereby reducing infection risk. The researchers plan to further test the device using urine collected from volunteers, before testing its safety and efficacy in a human clinical trial.