Sunday, January 26, 2014

Health scan: How stubborn bacteria avoid antibiotics


Jerusalem Post - The mechanism used by some bacteria to survive antibacterial treatment has been revealed for the first time by Hebrew University of Jerusalem researchers.

The mechanism used by some bacteria to survive antibacterial treatment has been revealed for the first time by Hebrew University of Jerusalem researchers. They suggest that their work could pave the way for new ways to control such pathogens.

In addition to the known phenomenon in which some bacteria achieve resistance to antibiotics through mutation, there are other types, known as “persistent bacteria,” that are not resistant to the antibiotics but simply continue to exist in a dormant or inactive state when exposed to antibacterial treatment. These bacteria “awaken” when that treatment is over, resuming their detrimental tasks.

Until now, scientists have been aware of a connection between these kinds of bacteria and the pathogen’s naturally occurring toxin HipA, but they didn’t know the cellular target of this toxin and how its activity triggers dormancy of the bacteria.

Now, the Jerusalem researchers, led by Prof. Gadi Glaser of the faculty of medicine and Prof. Nathalie Balaban of the Racah Institute of Physics, have been able to show how this comes about. They demonstrated that when antibiotics attack these bacteria, the HipA toxin disrupts the chemical “messaging” process necessary for nutrients to build proteins. This is interpreted by the bacteria as a “hunger signal” and sends them into an inactive state (dormancy) in which they are able to survive until the antibacterial treatment is over.

The research on persistent bacteria has been conducted in Balaban’s lab for several years, focusing on the development of a biophysical understanding of the phenomenon.

It will be combined with other work being done in Glaser’s lab that focuses on fighting persistent bacteria in the hope of leading to more effective treatment for bacterial infections.   Read More