Biofilm formation and regulating genes of Salmonella enterica recovered from chicken and fish samples.

Keywords The study sought to evaluate the biofilm formation capacity and biofilm-related gene profiles of Salmonella enterica recovered from food of animal origins. A total of 24 Salmonella enterica strains were isolated from 215 samples collected from food of animal origins (Raw chicken breast (45 samples), breaded chicken product (45 samples), shrimp (25 samples), Mackerel fish (25 samples), sea bass fillet (25 samples), tilapia fillet (25 samples), and mugil fillet (25 samples)) in Al Qalyubia Governorate, Egypt, during 2020– 2022. Using the crystal violet quantitative microtiter plate method and Congo red agar plating, the isolates' ability to form biofilms was evaluated. Polymerase Chain Reaction analysis was used to identify the presence of four biofilm-related genes ( csgA, csgD, sdiA, and sipA ) in strains that were highly capable of forming biofilms. The results revealed that 62.50% (15/24) of the strains exhibited strong biofilm formation, 20.83% (5/24) were moderate biofilm producers, and 16.67 % (4/24) were weak biofilm producers. Over 80% of the Salmonella enterica strains that are known to produce strong biofilm were found to be positive for all four of the biofilm-related genes when the strains were analyzed. The current study findings underscored the importance of developing effective preventive and control techniques to address the issues posed by biofilm formation in the food industry.