Diversity Among Clinical and Fresh Produce Isolates of <em>Stenotrophomonas</em>: Insights Through a One Health Perspective

Fresh produce represents a key interface in the One Health continuum, connecting environmental, agricultural and clinical settings where opportunistic bacteria can circulate. Among them, Stenotrophomonas comprises an environmental genus of growing concern due to its multidrug resistance and rising clinical relevance. To investigate their diversity and pathogenic potential, nineteen isolates from vegetables, irrigation water and hospital sources were characterized by MLST, growth kinetics, biofilm formation, antimicrobial susceptibility assays and whole-genome sequencing. Phylogenetic analyses grouped 12 isolates within the Stenotrophomonas maltophilia complex (SMC) (clinical S. maltophilia (n = 7) and environmental S. geniculata (n = 4) and S. sepilia (n = 1)) and seven non-SMC isolates, including S. indicatrix (n = 5) and two unclassified clinical strains. Environmental S. geniculata and S. sepilia isolates showed robust growth at 37 °C and biofilm formation comparable to clinical lineages. Genomic analyses further revealed shared mobile loci (afaD, fhaB, zot) and homologous plasmids between environmental and clinical isolates, suggesting a connected gene pool. The identification of environmental strains with virulence-associated traits and clinical-like phenotypes supports fresh produce as a potential reservoir and transmission route for opportunistic Stenotrophomonas, underscoring the need for integrated surveillance across the food–health interface.