New research may allow scientists to prevent a certain
strain of E. coli
bacteria from causing illness in people who have contracted
the bacterial infection.
This development may also be effective in preventing
other types of bacterial infections, and help reduce
dependence on antibiotic treatments, the researchers
said.
Scientists at the University of Texas Southwestern
Medical Center at Dallas have identified a receptor,
QseC, that E. coli uses to receive signals
from the intestine and subsequently transmit the bacteria
into the intestine to cause infection and symptoms
such as diarrhea.
Once the infection-releasing receptor was identified,
the researchers were then able to block the signals
sent from the intestine using phentolamine, an alpha
blocker commonly prescribed to control high blood
pressure.
"This receptor is found in many pathogens, so
we can use this knowledge to design specific antagonists
to block bacterial infections," study author
Dr. Vanessa Sperandio, assistant professor of microbiology
at the university, said in a prepared statement.
The researchers studied the effect of adrenergic
antagonists -- including alpha and beta blockers --
on the QseC receptor's capacity to receive signals
from the hormones in the intestine. Phentolamine was
successful in adhering to the receptor and filling
the space that it would normally fill with the epinephrine
and norepinephrine signals sent from the intestines.
The findings from this study, published in this week's
Proceedings of the National
Academy of Sciences, may provide better
insight into future treatments for bacterial infections
without the use of antibiotics, the researchers said.
"Overuse of antibiotics has led bacteria to
develop resistance to antibiotics, so a novel type
of therapy is needed," Sperandio said.