Bladder infections — also called cystitis or urinary tract infections — occur when bacteria enters the urinary tract, attaches itself to the surfaces and causes the bladder to become inflamed. More than half of all women get at least one bladder infection in their lifetime, while the condition is far rarer in men.
According to WebMD, doctors theorize that women are more prone to bladder infections than men are because they have shorter urethras — the tube that carries urine out of the bladder. "This relatively short passageway — only about an inch and a half long — makes it easier for bacteria to find their way into the bladder."
Almost always, infection is caused by the intestinal bacterium E. coli. In Nature Communications. researchers from the University of Basel and the ETH Zurich explain how this bacterium attaches to the surface of the urinary tract via a protein with a sophisticated locking technique, which prevents it from being flushed out by the urine flow.
The researchers found that E. coli adheres to the urinary tract under urine flow via the protein FimH and subsequently travels up the urethra. The pathogen has long, hair-like appendages with the protein FimH at its tip, forming a tiny hook. This protein, which adheres to sugar structures on the cell surface, has a special property: It binds more tightly to the cell surface of the urinary tract the more it is pulled. As strong tensile forces develop during urination, FimH can protect the bacterium from being flushed out.
The insights they gained by understanding precisely how the protein helps the bacteria adhere itself to the urinary tract will allow the team to test alternative treatments for bladder infections that may not necessarily include antibiotics.
Urinary tract infections are the second most common reason for prescribing antibiotics, the team says. Yet, in times of increasing antibiotic resistance, the focus is moving toward developing drugs that would prevent E. coli infections — that is, drugs that would prevent the initial FimH attachment of the bacteria to the urinary tract.
If it works, it would open up the possibility of reducing the use of antibiotics and prevent the further development of resistance.