Patulin interference with ATP binding cassette transferring auto inducer −2 in Salmonella typhi and biofilm inhibition via quorum sensing

Salmonella typhi are Gram-negative pathogens that infect many hosts including humans and animals and cause diseases ranging from gastroenteritis and diarrhea to life-threatening systemic syndrome. Owing to the metabolic versatility, they will colonize as multi cellular aggregates on various surfaces to enhance the virulence by forming a biofilm in which bacterial cells are more resistant to antibiotics than planktonic cells. Quorum Sensing (QS) is a cell-to-cell communication mechanism in the bacterial system to coordinate group behaviors such as biofilms formation and virulence factors production. In QS system ATP Binding Cassette (ABC) transporter component, LsrA, plays a key role to transport autoinducer-2 (AI-2) to increase the cell density. In order to reduce biofilm formation, patulin was selected as a natural QS inhibitor and its function was studied by biofilm inhibitory assays. Significant differences in the spectroscopic values were obtained between antibiotic resistance of kanamycin (30 μg/ml) and patulin (30 μg/ml). Furthermore, to distinguish the molecular level interaction of LsrA, patulin and AI-2 were docked. Both the compounds were interact in the same pose with Glide score of −4.237 kcal/mol and −7.126 kcal/mol respectively. These results will suggest that patulin is the efficient Quorum Sensing Inhibitor to control biofilm formation in S.typhi. Keywords: Salmonella typhi, Quorum sensing, LsrA, AI-2, Patulin