Abstract
This study investigated the phenotypic and genomic characteristics of Vibrio parahaemolyticus isolated from retail shrimp at traditional farmers' markets and online platforms in China. Phenotypic characteristics including auto-aggregation, motility, NaCl tolerance, and biofilm formation were evaluated alongside genomic analyses in 13 isolates. Considerable phenotypic diversity was observed, with strong correlations between biofilm formation and NaCl tolerance (r = 0.98), as well as auto-aggregation (r = 0.91). Genome assemblies showed > 95% ANI to reference strains, and pan-genome profiling indicated an expanded repertoire of biofilm-associated genes in online isolates. Farmers' market isolates tended to carry more antibiotic resistance genes (bla (CARB) , aphA) and efflux pump-associated genes, whereas online isolates more frequently harbored stress response genes (adiAC, cadC, mazEF) and uniquely contained the virulence gene tdh. These findings suggest that retail environments may be associated with distinct adaptive strategies and pathogenic potential in V. parahaemolyticus, underscoring the need for cautious interpretation and tailored surveillance approaches.