Patent ID: 8202695

Claim:
A method for identifying an agent for decreasing expression of virulence factors in a culture of Gram positive bacteria, the method comprising: contacting a first sample of the culture of the bacteria with an analog of guanine or guanosine, or a non-metabolizable analog of amino acid isoleucine or a non-metabolizable analog of amino acid valine, the analog being present at a concentration effective to activate repression by CodY, wherein the culture comprises at least one strain of the bacteria grown in a chemically defined minimal medium, and wherein a second sample of the culture not so contacted and otherwise identical serves as a control; and analyzing in the first sample and the second sample expression of a CodY regulated gene product, wherein the CodY-regulated gene product is an RNA or a protein, wherein the RNA is an mRNA, wherein decreased expression of the gene product in the first sample compared to expression of the gene product analyzed in the second sample identifies the analog as an agent for limiting expression of virulence factors in cells of the culture of the Gram positive bacteria.