Journal of Food Processing & Technology

AHLs based quorum signaling in the management of food borne pathogens

International Conference on Food Microbiology

August 08-10, 2016 Birmingham, UK

Prathap Kumar Halady Shetty and Venkadesaperumal Gopu

Pondicherry University, India

Posters & Accepted Abstracts: J Food Process Technol

Abstract:

Bacterial isolates from various food sources were screened for their quorum signaling using the bio-sensor strain Chromobacterium violaceum CV026. The methanolic extract of Scigium cumini, was screened for its quorum quenching (QQ) activity. Active components exhibiting the QQ activity were screened by molecular docking analysis. The phytochemical components which exhibited high docking scores were selected for regulating selected QS-dependent phenotypes. Further dynamics simulation was performed to study the conformational changes in LasR receptor upon binding with active components. Out of 86 Gram-negative isolates, three were found to produce AHLs by inducing violacein production in the bio-sensor strain and they were identified as K. pneumoniae, P. aeruginosa and Y. enterocolitica. S. cumini extract exhibited pronounced quenching activity at the concentration of 4 mg/ml. Molecular docking analysis attributed the QQ activity of S. cumini to quercetin and petunidin (docking scores of 7.20 and 8.84 Kcal/mol). On screening the activity of selected active components against QS-dependent phenotypes, both quercetin and petunidin exhibited significant reduction in biofilm formation and EPS production in a concentration-dependent manner. Synergistic activity of conventional antibiotics with petunidin and quercetin enhanced the susceptibility of tested pathogen. Molecular dynamics simulation predicted that QS inhibitory activity occurs through the conformational changes between the receptor and active component complex and the LasR-active components complex was found to be more stable than the LasR-AHL complex. The findings suggest that S. cumini and its active components can serve as a novel QS-based antibacterial/anti-biofilm approach for the management of food-borne pathogens.

Biography :

Email: pkshalady@yahoo.co.uk