Diversity Among Clinical and Fresh Produce Isolates of Stenotrophomonas: 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.

新鲜农产品是健康一体（One Health）连续体中的关键交互界面，连接起环境、农业与临床场景，为机会致病菌的循环传播提供了通路。其中，寡养单胞菌属（Stenotrophomonas）因多重耐药性及日益凸显的临床相关性，成为受到持续关注的环境菌群。
为探究该属细菌的多样性与致病潜力，研究人员对来自蔬菜、灌溉水及医院来源的19株分离株开展了多位点序列分型（Multi-Locus Sequence Typing, MLST）、生长动力学检测、生物被膜形成能力分析、抗菌敏感性试验及全基因组测序。
系统发育分析结果显示，12株分离株归入嗜麦芽寡养单胞菌复合群（Stenotrophomonas maltophilia complex, SMC），其中包括7株临床来源的嗜麦芽寡养单胞菌（S. maltophilia）、4株环境来源的膝状寡养单胞菌（S. geniculata）与1株腐生寡养单胞菌（S. sepilia）；剩余7株为非SMC群分离株，涵盖5株印度寡养单胞菌（S. indicatrix）与2株未分类临床菌株。
环境来源的膝状寡养单胞菌与腐生寡养单胞菌分离株在37℃条件下表现出强劲的生长能力，且生物被膜形成能力与临床谱系菌株相当。
基因组分析进一步揭示，环境与临床分离株共享移动基因座（afaD、fhaB、zot）与同源质粒，提示二者拥有共有的基因库。
本次研究鉴定出携带有毒力相关性状且具备类临床表型的环境菌株，佐证了新鲜农产品可作为机会性寡养单胞菌的潜在储存宿主与传播途径，强调了需针对食品-健康界面开展一体化监测的必要性。