Anti-Adhesion and Antibiofilm Activity of Eruca sativa Miller Extract Targeting Cell Adhesion Proteins of Food-Borne Bacteria as a Potential Mechanism: Combined In Vitro-In Silico Approach

Abstract

Bacterial cells have the ability to form biofilm onto the surfaces of food matrixes and on food processing equipment, leading to a source of food contamination posing serious health implications. Therefore, our study aimed to determine the effect of Eruca sativa Miller (E. sativa) crude extract against biofilms of food-borne bacteria along with in silico approaches to investigate adhesion proteins responsible for biofilm activity against the identified phytochemicals. The antibacterial potential of crude extract was evaluated using agar well diffusion technique and combinations of light and scanning electron microscopy to assess the efficacy of crude extract against the developed biofilms. Our results showed that crude extract of E. sativa was active against all tested food-borne bacteria, exhibiting a rapid kinetics of killing bacteria in a time-dependent manner. MIC and MBC values of E. sativa crude extract were found to be ranging from 125 to 500 µg/mL and 250 to 1000 µg/mL respectively. Furthermore, inhibition of developed biofilm by E sativa was found to be ranging from 58.68% to 73.45% for all the tested strains. The crude extract also reduced the viability of bacterial cells within biofilms and amount of EPS (ranging 59.73–82.77%) in the biofilm matrix. Additionally, the microscopic images also revealed significant disruption in the structure of biofilms. A molecular docking analysis of E. sativa phytochemicals showed interaction with active site of adhesion proteins Sortase A, EspA, OprD, and type IV b pilin of S. aureus, E. coli, P. aeruginosa, and S. enterica ser. typhi, respectively. Thus, our findings represent the first demonstration of E. sativa crude extract’s bioactivity and potency against food-borne bacteria in their planktonic forms, as well as against the developed biofilms. Therefore, a possible mechanistic approach for inhibition of biofilm via targeting adhesion proteins can be explored further to target biofilm producing food-borne bacterial pathogens.