Scientists at Washington University School of Medicine in St. Louis have found new clues to why some urinary tract infections recur persistently after multiple rounds of treatment.
Their research, conducted in mice, suggests that the bacteria that cause urinary tract infections take advantage of a cellular waste disposal system that normally helps fight invaders. In a counterintuitive finding, they learned that when the disposal system was disabled, the mice cleared urinary tract infections much more quickly and thoroughly.
"This could be the beginning of a paradigm shift in how we think about the relationship between this waste disposal system, known as autophagy, and disease-causing organisms," says senior author Indira Mysorekar, PhD, assistant professor of obstetrics and gynecology and of pathology and immunology. "There may be other persistent pathogens that have found ways to exploit autophagy, and that information will be very useful for identifying new treatments."
The results will be published the week of June 18, 2012, in the early online edition of The Proceedings of the National Academy of the Sciences.
Urinary tract infections are very common, particularly in women. In the United States alone, annual treatment costs are estimated to run as high as $1.6 billion. Scientists believe 80 percent to 90 percent of these infections are caused by the bacterium Escherichia coli (E. coli).
Data from the new study and earlier results have led Mysorekar and her colleagues to speculate that E. coli that cause recurrent urinary tract infections may hide in garbage-bin-like compartments within the cells that line the urinary tract.
These compartments, found in nearly all cells, are called autophagosomes. They sweep up debris within the cell, including harmful bacteria and worn-out cell parts. Then, they merge with other compartments in the cell that are filled with enzymes that break
|Contact: Michael C. Purdy|
Washington University School of Medicine