Molecule Keeps Bacteria Like Salmonella in
Check
2008-Aug-22
By
-- Robert Preidt
FRIDAY, Aug. 22 (HealthDay News) -- A molecule that tames
bacteria that cause gastroenteritis, tularemia and severe diarrhea
has been identified by researchers at the University of Texas
Southwestern Medical Center at Dallas.
The finding, they say, could help in the development of new
drugs to combat increasing microbial resistance to antibiotics.
The molecule LED209 blocks a bacterial receptor, called QseC
sensor kinase, from biochemical signals from the host that trigger
bacteria to release toxins and cause illness.
"What we have here is a completely novel approach to combating
illness," study senior author Dr. Vanessa Sperandio, an associate
professor of microbiology and biochemistry, said in a UT
Southwestern news release.
In studies in vitro, the researchers found that LED209 blocked
the QseC sensors in
E. coli, salmonella, and
Francisella tularensis bacteria. In mice, LED209 prevented
salmonella and
F. tularensis from causing illness.
The findings were published online Aug. 21 in
Science.
Conventional antibiotics kill bacteria. Killing or inhibiting
the growth of some bacteria "angers" them and causes them to
release toxins. LED209 allows bacteria to grow but prevents
virulence that causes illness, according to the study.
"The sensors in bacteria are waiting for the right signal to
initiate expression of virulent genes," Sperandio explained. "Using
LED209, we blocked those sensing mechanisms and basically tricked
the bacteria to not recognize that they were within the host. When
we did that, the bacterial pathogens could not effectively cause
disease in the treated animals."
Allowing the bacteria to survive also reduces the likelihood it
will develop drug resistance.
The study looked at how LED209 affected three pathogens, but the
researchers believe that drugs that target QseC could have wider
use, because the sensor is present in at least 25 important animal
and plant pathogens, including those that cause lung infections and
Legionnaire's disease.
More information
The U.S. National Institute of Diabetes and Digestive and Kidney
Diseases has more about
bacteria and foodborne illness.
HealthDay News
Copyright © 2008
ScoutNews,
LLC. All rights reserved.
The information in this article, including reference materials, are provided to you solely for educational or research purposes. Information in reference materials, are not and should not be considered professional health care advice upon which you should rely. Health care information changes rapidly and consequently, information in this article may be out of date. Questions about personal health should always be referred to a physician or other health care professional.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
