Characterizing the formation and cross-contamination potential of multi-species biofilms in poultry processing environments: S. Enteritidis, C. jejuni and C. perfringens

This study investigated the cross-contamination dynamics of biofilms preformed on stainless steel (SS) coupons on chicken skin and chicken meat by modeling surface-to-food transfer by contact and surface-to-food transfer in fluids. Additionally, mono-, dual-, and multi-species biofilms were examined to understand the effects of environmental conditions on biofilm-forming abilities. The results of crystal violet (CV) assay revealed that a dual-species biofilm of Salmonella Enteritidis with Campylobacter jejuni and a multi-species biofilm of S. Enteritidis with C. jejuni and Clostridium perfringens cultivated for 72 h under aerobic conditions exhibited significantly higher biofilm-forming abilities than the other biofilm types. Consistent with the CV assay findings, the multi-species biofilm exhibited significantly higher extracellular DNA and protein levels than the other biofilm types. Furthermore, the results highlighted the significant increase in cultivable counts when S. Enteritidis formed dual- or multi-species biofilms with C. jejuni or C. perfringens, indicating a synergistic effect among the strains. Additionally, the analysis of cross-contamination models revealed that the pressing method induced greater cross-contamination across most biofilm types irrespective of the food sample or biofilm characteristics. This suggests that surface-to-food contact played a more influential role in cross-contamination than surface-to-food interactions in fluids. Overall, our findings provide insights into the intricate dynamics of preformed biofilms on SS coupons in contact with chicken skin and meat, underscoring the significance of the relationship between biofilm formation and cross-contamination. [Display omitted] •S. Enteritidis showed synergistic effect with C. jejuni and C. perfringens.•Multi-species biofilm exhibited the highest quantities of eDNA and protein.•S. Enteritidis showed higher cultivable counts in dual- and multi-species biofilms.•Higher cross-contamination was shown with pressing (surface-to-food contact) method.