Evolution of Resistance to Quorum-Sensing Inhibitors

The major cause of mortality and morbidity in human beings is bacterial infection. Bacteria have developed resistance to most of the antibiotics primarily due to large-scale and "indiscriminate" usage. The need is to develop novel mechanisms to treat bacterial infections. The expression of pathogenicity during bacterial infections is mediated by a cell density-dependent phenomenon known as quorum sensing (QS). A wide array of QS systems (QSS) is operative in expressing the virulent behavior of bacterial pathogens. Each QSS may be mediated largely by a few major signals along with others produced in minuscule quantities. Efforts to target signal molecules and their receptors have proved effective in alleviating the virulent behavior of such pathogenic bacteria. These QS inhibitors (QSIs) have been reported to be effective in influencing the pathogenicity without affecting bacterial growth. However, evidence is accumulating that bacteria may develop resistance to QSIs. The big question is whether QSIs will meet the same fate as antibiotics.