The most common type of hospital-associated infection may be preventable with a vaccine, new research in mice suggests.
The experimental vaccine, developed by researchers at Washington University School of Medicine in St. Louis, prevented urinary tract infections associated with catheters, the tubes used in hospitals and other care facilities to drain urine from a patient’s bladder.
Each day a catheter is present in the urethra and the bladder, the risk of urinary tract infection increases. Nearly every patient who has a catheter for more than 30 days acquires a urinary tract infection. The infections make urination painful and can damage the bladder. If untreated, bacteria can cross into the bloodstream and cause sepsis, a potentially life-threatening complication.
“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.”
The study is available online Sept. 17 in Science Translational Medicine.
Manufacturers typically coat catheters with antibiotics to reduce the risk of infection. But Flores-Mireles and her colleagues in the laboratory of Scott Hultgren, PhD, showed that inserting catheters into the bladder provokes an inflammatory response that results in the catheter being covered with fibrinogen, a blood-clotting protein.
Fibrinogen shields bacteria from the antibiotics and provides bacteria with a landing pad to adhere to and food to consume as they establish an infection, the research revealed.
“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.”
The urethra and bladder of a mouse are too small to insert a full catheter into, but the scientists showed that surgically implanting a small segment of catheter into the bladder via the urethra increased vulnerability to infection in a similar fashion.
Working with Enterococcus faecalis, a common cause of catheter-associated urinary tract infections, Flores-Mireles showed that a protein on the end of the pili, EbpA, binds to fibrinogen and makes it possible for the bacteria to begin forming biofilms.
When Flores-Mireles prevented the bacteria from making EbpA, they couldn’t start infections.
“This protein is like the anchor of a boat,” she said. “Without the anchor, the infection is at the mercy of the waves and gets washed away.”
Next, the researchers injected the mice with a vaccine containing EbpA. The vaccine caused the animal’s immune systems to produce antibodies that blocked EbpA and stopped the infectious process.
The scientists are testing to see if the vaccine helps mice clear established infections of E. faecalis. They also are working to develop a monoclonal antibody that blocks EbpA to prevent catheter-associated infections in the urinary tract and elsewhere in the body.
“We took a closer look at this protein and found that one-half of it is essential for binding to fibrinogen to induce infections,” Flores-Mireles said. “The segment of genetic code that makes this part of the protein is also found in the genes of many other bacteria that cause urinary tract infections, so a vaccine, antibody or drug that blocks this part of the protein may help prevent other infections linked to catheters in the urinary tract and in other parts of the body.”
The research was based at Washington University’s Center for Women’s Infectious Disease Research, which is directed by Hultgren, the Helen L. Stoever Professor of Molecular Microbiology.
This work was supported by a Berg-Morse Postdoctoral Fellowship and National Institute of Diabetes and Digestive and Kidney Diseases grants R01-DK051406 and P50-DK0645400 from the National Institutes of Health (NIH).
Flores-Mireles AL, Pinkner JS, Caparon MG, Hultgren SJ. EbpA vaccine antibodies block binding of Enterococcus faecalis to fibrinogen to prevent catheter-associated baldder infection in mice. Science Translational Medicine, online Sept. 17.
Michael C. Purdy | Eurek Alert!
UC San Diego researchers develop sensors to detect and measure cancer's ability to spread
06.12.2018 | University of California - San Diego
New cancer immunotherapy approach turns immune cells into tiny anti-tumor drug factories
05.12.2018 | University of California - San Diego
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals
Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.
Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.
Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...
Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.
The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.
06.12.2018 | Event News
03.12.2018 | Event News
28.11.2018 | Event News
07.12.2018 | Life Sciences
07.12.2018 | Materials Sciences
07.12.2018 | Physics and Astronomy