Native environmental microbiota promotes Listeria monocytogenes attachment and biofilm resilience

Authors: FALCO, IRENE - Orise Fellow; YANG, YISHAN - Orise Fellow; Patel, Jitendra; Nou, Xiangwu

Submitted to: Food Bioscience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/28/2025
Publication Date: 12/29/2025
Citation: Falco, I., Yang, Y., Patel, J.R., Nou, X. 2025. Native environmental microbiota promotes Listeria monocytogenes attachment and biofilm resilience. Food Bioscience. 76. Article e108209. https://doi.org/10.1016/j.fbio.2025.108209.
DOI: https://doi.org/10.1016/j.fbio.2025.108209

Interpretive Summary: Listeria monocytogenes is a major foodborne bacterial pathogens that is often present in various food production environments. It can form structures called biofilms on various surfaces and serve as a persistent source for recurring contaminations. In this study, ARS researchers examined the effect of microorganisms collected from a fresh-cut produce production facility (referred to as "native environmental microbiota" here) on the biofilm formation and survival of L. monocytogenes. This study demonstrated that the native environmental microbiota strongly increased the initial surface binding and biofilm formation by L. monocytogenes and hence the resistance to antimicrobial treatment. The information can be used by fresh food processors for better understanding the process of biofilm formation and developing more effective treatment targeting biofilms formed by multiple species of microorganisms.

Technical Abstract: The persistence of Listeria monocytogenes in food processing environments is a major food safety concern. This study examined the effects of undefined native environmental microbiota (NEM) from fresh produce processing facilities on L. monocytogenes biofilm formation and tolerance to antimicrobial treatments. L. monocytogenes monospecies and multispecies cultures with NEM were grown under static and low-shear flow conditions and analysed for surface attachment, biofilm formation, biofilm resilience, and biofilm topology. L. monocytogenes exhibited significantly increased surface attachment and biofilm formation in the presence of NEM, and the multispecies biofilms showed increased tolerance to antimicrobial treatment by quaternary ammonium compounds (QAC) or short wavelength UV light (UV-C). Fluorescent imaging showed that L. monocytogenes formed discrete clusters partially or entirely embedded in the matrix of NEM multispecies biofilms. Overall, these observations suggested that NEM provided attachment anchorage, structural protection, and biofilm resilience to L. monocytogenes in multispecies biofilms, and thereby limiting the efficacy of sanitation practices. Tailored cleaning strategies should therefore target biofilm architecture and interspecies interactions to effectively reduce pathogen persistence in food processing environments.