Researchers discover a compound that controls Listeria

In a year when cantaloupe tainted with the bacterium Listeria monocytogenes killed 30 people, the discovery of a compound that controls this deadly bacteria -- and possibly others -- is great news.


Cornell researchers have identified a compound called fluoro-phenyl-styrene-sulfonamide (FPSS) that is safe for mammals but stops Listeria in its tracks. It interrupts a mechanism that controls genes that are expressed when the bacterium experiences a rapid change in its environment.

The discovery, reported in the November/December issue of mBio, a journal of the American Society for Microbiology, offers new directions for basic research on how L. monocytogenes and other bacteria survive in a wide range of rapidly changing hostile conditions, from fluctuating temperatures to the low pH levels found in the human stomach. Also, there is a strong possibility that FPSS eventually may be developed as a drug to combat listeriosis and other bacterial infections.

For a foodborne pathogen to infect a human, it must be able to survive rapid changes in its environment, ranging from cold of refrigeration and heat from cooking to highly acidic stomach conditions and osmotic and anaerobic states found in the small intestines. To do so, L. monocytogenes and certain other bacteria employ a "stress-responsive alternative sigma factor" called sigma B, which controls more than 150 genes, including those that contribute to virulence and survival in host-associated stress conditions, including genes essential for the bacteria to cross the gastrointestinal tract, according to the study. 

This is a newly emerging approach in the search for antibiotics that are not dangerous to mammals but stop such pathogens as Listeria, and could be a possible treatment against other organisms.

Fuente: http://www.news.cornell.edu/stories/Jan12/Listeria.html

Aporte: María José Peralta S.