Scientists believe that the human body’s immune system can actually fight off a urinary tract infection (UTI) without the help of antibiotics. Duke University researchers found a pathway through which bladder cells can actually kick out the bacteria that cause UTIs – and are now looking into how they can harness it to treat the infections without antibiotics. "We found that the process which cells use to secrete chemicals also appears to be the way to clear urinary tract infections," says researcher Yuxuan Phoenix Miao.
UTIs are usually caused by E. coli (Escherichia coli) or other bacteria entering the urinary tract and attaching to the cell wall of the bladder, urethra, or kidneys (with kidney infections being the most severe). There are currently 8.1 million doctors’ visits annually in the US just as a result of UTIs.
Miao explains bacterial pathogens hide within a membranous vesicle in the bladder cells. A protein complex important for secreting hormones called ‘exocyst’ can recognize and locate bacteria hiding in those vesicles, then promote transport of these bacteria-laden vesicles towards the cell surface, and throw the bacteria out of the bladder cell.
As explained, the immune system usually sends in lysosomes – organelles that eat and break down virtually anything in a cell, including bacteria. But sometimes, the bacteria survive and the lysosome eventually bursts, and the freed bacteria go back and re-infect the cell.
Not to worry, scientists say that lysosomes can detect if the bacteria they’ve eaten isn’t breaking down, and vomit up the offending bacteria – which means they can be cleared away by other parts of the immune system.
Researchers are now looking into current medicines and other substances to see if they can trigger this natural clearing mechanism with more accuracy and control.