Dual-species biofilms of Escherichia coli and Pseudomonas promote temperature-dependent cross-contamination on meat surfaces

Temperature and contact surfaces are critical factors influencing biofilm formation of microbial communities derived from both lab and natural environments. However, there is limited understanding regarding how different temperatures impact transfer dynamics of individual microbial species between meat surfaces in dual-species biofilms. In this study, we evaluated the biofilm-forming capabilities of various meat-derived Escherichia coli and Pseudomonas strains on pork surfaces at 15 and 25 ℃. The results revealed that lower temperature had a significant negative effect on the growth fitness of E. coli compared to Pseudomonas. Two robust biofilm-forming strains, E. coli C-13 and P. fluorescens S_1-2 3, were selected under both temperature conditions to further explore their interactions in dual-species biofilms on meat surfaces. The results showed that E. coli exhibited a competitive growth advantage at 25 ℃, while Pseudomonas displayed enhanced growth at 15 ℃, indicating temperature-dependent competition patterns. Additionally, three established mathematical models were utilized to simulate the transfer dynamics of the two strains within mono- and dual-species biofilms. As anticipated, the numbers of transferred cells progressively declined with increased imprinting reactions between the meat surfaces. Interestingly, the transfer rates of both strains markedly improved in dual-species vs. mono-species biofilms at 15 ℃, highlighting the influential role of inter-species interactions on transfer dynamics of microbes that may cross-contaminate meats. Our findings advance current understanding of mono- and dual-species biofilm development on meat surfaces under different temperature conditions. They also offer scientific evidence to support strategies for controlling microbial cross-contamination during meat processing to ensure product safety.