Microbial Community Associations With Listeria monocytogenes in Food Processing Environments: A Systematic Review and Meta-Analysis.

Listeria monocytogenes persistence in food processing environments challenges current understanding of microbial community dynamics. This systematic review and meta-analysis examined peer-reviewed studies that screened for Listeria spp. and performed culture-independent metagenomics on FPE surface samples. Following PRISMA guidelines, we searched PubMed, Web of Science, and Food Science and Technology Abstracts databases, screening 464 studies, with 73 qualifying for full-text review. Seven studies met the inclusion criteria for final analysis, encompassing 1659 environmental samples from meat processing (n = 4 studies) and produce facilities (n = 3 studies). Meta-analysis using random effects models revealed no significant correlation between Listeria presence and overall microbial community alpha diversity (Shannon: z = -0.89, p = 0.40; inverse Simpson and Chao1 indices similarly non-significant). This finding challenges previous assumptions about the relationship between microbial diversity and pathogen persistence. Differential abundance analyses identified three genera most frequently associated with Listeria presence across multiple studies: Pseudomonas, Psychrobacter, and Acinetobacter. These Gammaproteobacteria are characterized as aerobic biofilm formers capable of growth at refrigeration temperatures. One study using rigorous mixed-effects modeling identified Veillonella as significantly associated with L. monocytogenes presence, suggesting potential anaerobic niche interactions within biofilm communities. Synthesis of metabolic capabilities reported in the literature suggests these associated genera may provide structural biofilm matrices and potentially complementary metabolic functions that could facilitate L. monocytogenes survival in FPE conditions. However, the genus-level resolution of 16S rRNA amplicon sequencing data and methodological variations across studies limit definitive conclusions about specific metabolic interactions. These findings indicate that L. monocytogenes persistence appears to be associated with specific microbial partners rather than overall community diversity metrics. Understanding these ecological relationships may inform targeted control strategies focusing on biofilm-forming genera that create favorable conditions for Listeria survival in food processing environments.