Food color 'Azorubine' interferes with quorum sensing regulated functions and obliterates biofilm formed by food associated bacteria: An and approach
Authors: Md Tabish Rehman
Altaf Khan
Pravej Alam
Thamer A Albalawi
Mohamed F Al-Ajmi
Nasser A Al-Shabib
Javed Masood Khan
Syed Ali Shahzad
Fohad Mabood Husain
Abdullah A Alyousef
Mohammed Arshad
Jakeera B Syed
Journal: Saudi journal of biological sciences (2020)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Azorubine; Biofilm; Food; Molecular docking; Quorum sensing
Affiliations: Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, 2456, Riyadh 11451, Saudi Arabia., Department of Pharmacognosy, College of Pharmacy, King Saud University, 2460, Riyadh 11451, Saudi Arabia., Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, 2460, Riyadh 11451, Saudi Arabia., Department of Pharmacology and Toxicology, Central Laboratory, College of Pharmacy, King Saud University, 2460, Riyadh 11451, Saudi Arabia., Department of Biology, Prince Sattam bin Abdulaziz Univrsity, Alkharj, Saudi Arabia., College of Medicine and Dentistry, Dar Al Uloom University, Al Mizan St, Al Falah, Riyadh 13314, Saudi Arabia.

Abstract:  Quorum sensing (QS) plays a crucial role in different stages of biofilm development, virulence production, and subsequently to the growth of bacteria in food environments. Biofilm mediated spoilage of food is one of the ongoing challenge faced by the food industry worldwide as it incurs substantial economic losses and leads to various health issues. In the present investigation, we studied the interference of quorum sensing, its regulated virulence functions, and biofilm in food-associated bacteria by colorant azorubine. In vitro bioassays demonstrated significant inhibition of QS and its coordinated virulence functions in Chromobacterium violaceum 12472 (violacein) and Pseudomonas aeruginosa PAO1 (elastase, protease, pyocyanin, and alginate). Further, the decrease in the production EPS (49-63%) and swarming motility (61-83%) of the pathogens was also recorded at sub-MICs. Azorubine demonstrated broad-spectrum biofilm inhibitory potency (50-65%) against Chromobacterium violaceum, Pseudomonas aeruginosa, E. coli O157:H7, Serratia marcescens, and Listeria monocytogenes. ROS generation due to the interaction between bacteria and azorubine could be responsible for the biofilm inhibitory action of the food colorant. Findings of the in vitro studies were well supported by molecular docking and simulation analysis of azorubine and QS virulence proteins. Azorubine showed strong binding to PqsA as compared to other virulent proteins (LasR, Vfr, and QscR). Thus, it is concluded that azorubine is a promising candidate to ensure food safety by curbing the menace of bacterial QS and biofilm-based spoilage of food and reduce economic losses. 

Retracted: No

PubPeer comments:
 Figure 5B appears to include a couple of images which overlap. The ones marked with red boxes are the same except for a horizontal flip. The yellow arrows indicate a common feature suggesting an overlap between those two images. *** Contrast enhanced  ,