How E coli triggers urinary infections
Washington: Researchers have unravelled the process by which an E coli strain triggers urinary tract infections and also induces the bladder to shed cells.
A-hemolysin (HlyA), a toxin secreted by many strains of E coli, may play an important, unexpected role during both the establishment and persistence of urinary tract infections (UTI).
UTIs are among the most common infectious diseases worldwide. Each year, 15 million US women have a UTI and nearly 50 percent of women will have at least one UTI in their lifetime, the journal Cell Host and Microbe reports.
Bugs known as uropathogenic E coli (UPEC) are the leading cause of both acute and chronic urinary tract infections. UPEC invade cells on the surface of the bladder, where it can stimulate exfoliation, or shedding, of bladder cells.
"Exfoliation of bladder cells can be viewed as a double-edged sword since it may benefit both the host and the invading bacteria," says Matthew Mulvey, associate professor of pathology at the University of Utah and study co-author.
"While shedding helps to get rid of infected cells, it can also promote spread of the bacteria both within and outside of the urinary tract. The goal of our investigation was to uncover possible mechanisms by which UPEC might prime bladder cells for shedding," said Mulvey, according to an Utah statement.
Mulvey and Bijaya Dhakal, Utah post-doctoral fellow in pathology, found that when UPEC infect bladder cells, they either multiply or persist in an inactive state for days or even weeks.
This persistence creates intracellular reservoirs of bacteria, which are thought contribute to chronic or recurrent infections.