New Experimental Vaccine Promises to Prevent UTIs Associated with Catheter

A new experimental vaccine may help prevent the most common urinary tract infections linked to use of catheters.

Urinary catheters are used to drain the bladder. Those with urinary incontinence or urinary retention, the health care providers recommend the use of catheter. But, with every single day the catheter is present in the urethra and the bladder, the risk of urinary tract infection (UTI) also increases. Those with catheter for more than 30 days are prone to acquire a UTI, due to which urinating becomes painful and bladder gets damaged.

If this condition is left untreated, the bacteria present, enters into the bloodstreams leading to sepsis - a life threatening complication.

Through the latest finding, researchers at the Washington University School of Medicine have come up with a novel experimental vaccine which they believe may help prevent UTI linked with use of catheter tubes in hospitals and other facilities.

"Catheter-associated urinary tract infections are very common," said first author Ana Lidia Flores-Mireles, PhD, a postdoctoral research associate at the School of Medicine. "Antibiotic resistance is increasing rapidly in the bacteria that cause these infections, so developing new treatments is a priority."

Most often, the manufactures coat the catheters with antibiotics - that helps lower the risk of infection. But in this study, the researchers showed that on inserting the catheter into the bladder, an inflammatory response occurs due to which the catheter gets layered with a blood clotting protein called fibrinogen. This protein protects bacteria from antibiotics and offers them a platform to adhere to and food to consume as they trigger an infection.

"The bacteria use long, thin hairs known as pili to anchor themselves to the fibrinogen, and then they can start to form biofilms, which are slimy coatings on the surface of the catheter composed of many bacteria," said co-author Michael Caparon Jr., PhD, professor of molecular microbiology. "The biofilms protect the bacteria from antibiotics and immune cells, further prevent them from being washed from the body by the flow of urine, and make it possible for bacteria to seed the lining of the bladder with infections."

This study was conducted on mice. Since the bladder is too small to insert the entire catheter, the researchers showed how when the catheter was surgically inserted into the bladder, the risk of infection increased. The experiment included the use of Enterococcus faecalis - the common cause of catheter-associated UTI. They showed the protein at the end of EbpA (endocarditis- and biofilm-associated pilus A) combines with fibrinogens and allows the bacteria to start forming biofilms. When the bacteria was prevented from making EbpA, they couldn't trigger infections.

The team is currently developing a monoclonal antibody that blocks EbpA to prevent catheter-caused infection in the urinary tract and elsewhere in the body.

The study is available online Sept. 17 in Science Translational Medicine.