Data_Sheet_1_Transcriptomic Analysis of Shiga Toxin-Producing Escherichia coli FORC_035 Reveals the Essential Role of Iron Acquisition for Survival in Canola Sprouts and Water Dropwort.xlsx

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that poses a serious threat to humans. Although EHEC is problematic mainly in food products containing meat, recent studies have revealed that many EHEC-associated foodborne outbreaks were attributable to spoiled produce such as sprouts and green leafy vegetables. To understand how EHEC adapts to the environment in fresh produce, we exposed the EHEC isolate FORC_035 to canola spouts (Brassica napus) and water dropwort (Oenanthe javanica) and profiled the transcriptome of this pathogen at 1 and 3 h after incubation with the plant materials. Transcriptome analysis revealed that the expression of genes associated with iron uptake were down-regulated during adaptation to plant tissues. A mutant strain lacking entB, presumably defective in enterobactin biosynthesis, had growth defects in co-culture with water dropwort, and the defective phenotype was complemented by the addition of ferric ion. Furthermore, gallium treatment to block iron uptake inhibited bacterial growth on water dropwort and also hampered biofilm formation. Taken together, these results indicate that iron uptake is essential for the fitness of EHEC in plants and that gallium can be used to prevent the growth of this pathogen in fresh produce.

肠出血性大肠杆菌（EHEC）是一种食源性病原体，对人类健康构成严重威胁。尽管EHEC主要存在于含肉食品中，但近期研究揭示了众多与EHEC相关的食源性爆发实际上是由于变质的芽苗菜和绿叶蔬菜等所致。为了探究EHEC如何适应新鲜蔬菜的环境，我们选取了EHEC分离株FORC_035，将其暴露于油菜芽苗（Brassica napus）和鸭舌草（Oenanthe javanica）中，并在与植物材料共培养1小时和3小时后对病原体的转录组进行了分析。转录组分析显示，在适应植物组织过程中，与铁摄取相关的基因表达被下调。一种缺乏entB基因的突变株，该基因可能存在肠菌素生物合成缺陷，在与鸭舌草共培养时表现出生长缺陷，而通过添加铁离子可以恢复其缺陷表型。此外，使用镓处理以阻断铁摄取不仅抑制了细菌在鸭舌草上的生长，还阻碍了生物膜的形成。综合这些结果，表明铁摄取对于EHEC在植物中的生存至关重要，且镓可用于预防该病原体在新鲜蔬菜中的生长。