Single- and Dual-Species Biofilm Formation by Shiga Toxin-Producing Escherichia coli and Salmonella, and Their Susceptibility to an Engineered Peptide WK2

Abstract

Shiga toxin-producing Escherichia coli (STEC) and Salmonella enterica are important foodborne pathogens capable of forming both single- and multi-species biofilms. In this study, the mono- and dual-species biofilms were formed by STEC O113:H21 and Salmonella enterica serovar Choleraesuis 10708 on stainless steel in the presence of beef juice over 5 d at 22 °C. The dual-species biofilm mass was substantially (p < 0.05) greater than that produced by STEC O113:H21 or S. Choleraesuis 10708 alone. However, numbers (CFU/mL) of S. Choleraesuis 10708 or STEC O113:H21 cells in the dual-species biofilm were (p < 0.05) lower than their respective counts in single-species biofilms. In multi-species biofilms, the sensitivity of S. Choleraesuis 10708 to the antimicrobial peptide WK2 was reduced, but it was increased for STEC O113:H21. Visualization of the temporal and spatial development of dual-species biofilms using florescent protein labeling confirmed that WK2 reduced cell numbers within biofilms. Collectively, our results highlight the potential risk of cross-contamination by multi-species biofilms to food safety and suggest that WK2 may be developed as a novel antimicrobial or sanitizer for the control of biofilms on stainless steel.

Continuous production and recirculation of plasma‐activated water bubbles under different flow regimes for mixed‐species bacterial biofilm inactivation inside pipelines

“…Day 10 produced significantly ( p < 0.05) higher biomass than day 6 surface‐attached cells and were categorized as weak biofilms. Several studies have reported a direct relationship between incubation time and biomass production (Ma et al, 2021; Prasad & Roopesh, 2023; Singla et al, 2014; Visvalingam, Zhang, et al, 2019; Yang et al, 2018). An increase in the biomass production of the mixed‐species consortia has also been positively correlated with disinfection resistance (Burmølle et al, 2006).…”

Bacteriophages for the Targeted Control of Foodborne Pathogens

“…Salmonella can survive in low-moisture foods such as powdered milk, chocolate, peanut butter, infant foods, cereal, and bakery products over extended periods of time [42]. Salmonella is known to form biofilms on glass slides [43] and stainless steel [44,45]. The ability to form biofilms enhances the ability of Salmonella to survive in food-processing plants.…”