Biofilm-Mediated Persistence of Salmonella in Poultry Processing: A Comprehensive Review of Isolate Heterogeneity, Stress Adaptation, and Antimicrobial Resistance.

Salmonella enterica remains a major foodborne pathogen in poultry-processing environments, where its persistence is largely attributed to biofilm formation on food-contact and non-food-contact surfaces. Despite extensive research on Salmonella control, persistent contamination continues to challenge food safety due to the complex interplay among isolate-specific traits, stress adaptation, and antimicrobial resistance (AMR). This review critically examines the phenotypic and genotypic determinants associated with Salmonella biofilm formation and evaluates their contributions to persistence, stress adaptation, and AMR. Emerging evidence also indicates that mixed-species interactions, particularly with Pseudomonas spp., can influence biofilm architecture, stress tolerance, and the long-term persistence of Salmonella in poultry-processing environments. Particular attention is given to processing-associated stresses, including temperature fluctuations, desiccation, nutrient limitation, and sublethal sanitizer exposure, which can induce adaptive responses that enhance biofilm development, promote persistence, and increase tolerance to antimicrobial interventions. The review further evaluates current detection approaches, including viability-based quantification methods such as digital droplet PCR, and discusses their limitations and applications in identifying and quantifying biofilm-associated and viable but nonculturable (VBNC) populations within processing environments. Existing control measures are assessed with emphasis on the challenges posed by mature biofilms and adaptive resistance mechanisms. Emerging antibiofilm technologies, including enzymatic treatments, bacteriophages, and UV-LED systems, are also examined for their potential industrial implementation. By integrating current knowledge on biofilm biology, stress adaptation, and AMR, this review provides a framework for developing targeted and sustainable strategies to mitigate Salmonella persistence in poultry-processing environments.