May 26, 2009

Bacteria have built-in thermometer

German scientists say they have discovered how bacteria measure temperature and thereby control rates of infection.

Researchers at the Helmholtz Centre for Infection Research in Braunschweig and the Braunschweig Technical University say they've show, for the first time, bacteria of the Yersinia genus possess a unique protein thermometer -- the protein RovA -- which assists them in the infection process.

The scientists said RovA is a multi-functional sensor, measuring both the temperature of its host as well as the host's metabolic activity and nutrients. If those are suitable for the survival of the bacteria, the RovA protein activates genes for the infection process to begin.

Yersinia can trigger various different diseases, of which the best well-known is the Yersinia pestis type that caused The Black Plague during medieval times, leading to the death of about a third of Europe's population.

The researchers, led by Petra Dersch, identified how the mechanisms work. The RovA protein plays a key role by reading the temperature for the bacteria. Depending on the environment of the bacteria, this protein either contains the factors required for the infection to begin or else adapts to life within the host.

The findings appeared online last week in the journal PLoS Pathogens.