QUORUM QUENCHING ABILITY OF DIETARY SPICE CINNAMOMUM VERUM ON PATHOGENIC BACTERIA

摘要

Quorum sensing is a bacterial cell communication mechanism mediated through signal molecules such as AHL’s. Many opportunistic pathogens use these quorum sensing circuits to coordinate their virulence gene expression. Wide range of naturally occurring substances particularly plant extracts have been evaluated for their ability to modulate quorum sensing in Gram-negative bacteria. Preliminary screening of popular food spices for QSI activity revealed that Cinnamomum verum (Dalchini) had good QSI activity. Recognizing its medicinal value and dietary consumption, an attempt was made to evaluate QSI activity of Cinnamomum verum on bacterial pathogens like Pseudomonas and Serratia and confirmed by using bioindicator organism Chromobacterium violaceum. Cinnamomum verum extract had more QSI activity than the antibacterial activity in Serratia. In Pseudomonas, the antibacterial activity was more while QSI activity was comparatively less. Interestingly spice extract could reduce swarming nature in both the organisms, which is one of the important virulent factor regulated by QS. The phytochemical components in the crude extract were analyzed by qualitative methods. MS analysis of the treated samples revealed the fact that AHL molecule is subjected to lysis or degradation. Chemical characterization of bioactive components in the crude extract of Cinnamomum verum is under process.