Cystitis How the bacteria in the urethra bite

How bacteria make their way through a bladder infection
Especially in the cold winter months, many people suffer from cystitis. Women are much more likely to be affected than men. Most of the E-coli bacteria are the cause of urinary tract infections. Researchers from Switzerland have now found out how the pathogens in the urethra, so as not to be flushed out of the urine.

Nearly every second woman gets a bladder infection
Especially in the cold season, many people suffer from a bladder infection. The most common signs of illness are burning and pain when urinating. Constant urgency is another indication of infection. Sometimes cramping pain, blood in the urine and fever occur. Although men can also get sick, according to health experts, up to 95 of those affected are female. Nearly every second woman suffers from cystitis at least once in her life. The fact that women are more often affected by cystitis than men is due to an anatomical difference. The urethra of women is about four centimeters shorter and thus more appropriate to allow invading bacteria to make their way up into the bladder.

Swiss researchers have demonstrated how bacteria that cause bladder infection settle in the urethra. (Image: Markus Bormann / fotolia.com)

Infection mostly triggered by intestinal bacteria
Cystitis is caused by germs. In eighty percent of cases, E. coli bacteria (Escherichia coli) are responsible. These migrate via the urethra to the bladder and trigger painful inflammations there. Researchers at the University of Basel and the Swiss Federal Institute of Technology (ETH) Zurich report in the journal "Nature Communications" that they have discovered how the germ, thanks to a cleverly designed protein, can attach itself to the surface of the urinary tract Prevent urine.

Germination can be recorded in the urethra
According to a report from the University of Basel, the researchers led by Prof. Timm Maier from the Biozentrum and Prof. Beat Ernst from the Pharmacy Center of the University of Basel, and Prof. Rudolf Glockshuber from the Institute of Molecular Biology and Biophysics at the ETH Zurich, discovered how the bacteria manage to capture the urinary fim with the protein FimH and still migrate up the urethra. The pathogens therefore have long filamentous cell processes at the end of which the protein FimH forms a tiny hook. This protein, which attaches itself to sugar structures on the cell surfaces of the urinary tract, binds all the more strongly to the sugar molecules, the stronger the bacterium is pulled. When the urine is excreted, the liquid flow produces strong tensile forces under which FimH protects the bacterium from flushing out.

Mechanical forces regulate bond strength
"By combining a variety of biophysical and biochemical methods, we were able to elucidate the binding behavior of FimH to unprecedented accuracy," Glockshuber said. The scientists showed for the first time how mechanical forces regulate the binding strength of FimH. "The protein FimH consists of two parts, with the second, non-sugar binding part controlling how firmly the first one binds to the sugar molecules," Maier says. "If both parts are now pulled apart by the urine flow, the Zuckerbindungsstelle snaps to. However, if the tensile forces decrease, the binding pocket opens. Now the bacteria can dissolve and travel up the urethra. "

Search for alternative treatment strategies
Although natural home remedies for bladder infections are often sufficient, urinary tract infections are the second leading cause of antibiotics prescribing, according to the University of Basel. The search for alternative treatment strategies is becoming increasingly important, not least because of increasing resistance. An anti-FimH attachment would therefore be a welcome alternative that would often eliminate the need for antibiotics. (Ad)