A novel research, led by Professor Emanuel Hanski from the Department of Microbiology and Molecular Genetics at the Medical School of the Hebrew University of Jerusalem, (Belotserkovsky et al., PLoS Pathogens 5(11): e1000651; dx.plos/10.1371/journal.ppat.1000651), identified a new array of genes in GAS and in a close relative, Group G Streptococcus (GGS), usually considered a commensal that do not harm the host. These genes are activated by a quorum-sensing peptide termed SilCR. SilCR is not functional in highly invasive GAS strains, suggesting that this array of genes may be involved in colonization and establishment of commensal host-bacterial relationships. The researchers further show that GAS and GGS strains can sense their respective SilCR molecules, thus coordinating their pathogenicity, and comprising a novel communication system between these bacteria. The research was funded by the Chief Scientist Office of the Israeli Ministry of Health, under the framework of ERA-NET PathoGenoMics, a European Commission funded imitative aiming at advancing transnational research in genome-based research programs on human-pathogenic microorganisms.

"This study opens up exciting possibilities for controlling the pathogenicity of Streptococcus A, which can cause several invasive, life-threatening illnesses," said Dr. Marion Karrasch-Bott, Coordinator of ERA-NET PathoGenoMics. "The researchers not only identified a new genetic element that controls bacterial virulence, but also an array of genes regulated by this element. This will help in our understanding of how bacterial-host interactions can lead to mutual existence in some cases, or to violent infections in other cases, and will eventually lead to innovative drugs that could prevent the bacteria from making the wrong decision."

Source: ERA-NET PathoGenoMics