Annelie Brauner Group

Defending the uroepithelium; new strategies for treatment of recurrent infections

Urinary tract infection is currently one of the 10 most common reasons for outpatient visits. Up to 60 percent of all women develop a urinary tract infection at least once in their life, and of these, 20% have the problem of recurrent infections. Children less often suffer from urinary tract infections but when the kidneys are involved up to 40% of them get renal scarring. Antibiotic-resistant bacteria are a growing problem and therefore there is a need to develop new treatment strategies.

The urinary tract functions in close proximity to the outside environment, yet must remain free of microbial colonization to avoid disease. It was previously thought that the urinary tract is maintained sterile by the flow of urine, which stops bacteria from lodging in the mucus membrane of the urinary tract. However, we have recently demonstrated that production of cathelicidin, an antimicrobial peptide, also protects from urinary tract infection by aggressively fending off bacteria. Within minutes after the uroepithelial cells are exposed to Escherichia coli, the most frequent urinary tract pathogen, rapid secretion of the newly synthesized active antimicrobial peptide occurs. We demonstrated that cathelicidin production is biologically relevant, whereby it is of importance for the establishment and severity of the disease.

In ongoing studies, we focus on new treatment strategies for patients with recurrent urinary tract infections, on signaling pathways leading to the expression of the antimicrobial peptide cathelicidin as well as on bacterial virulence factors enabling the bacteria to withstand traditional antibiotic treatment.