Differences in internalization and growth of Escherichia coli O157:H7 within the apoplast of edible plants, spinach and lettuce, compared with the model species Nicotiana benthamiana.
Differences in internalization and growth of Escherichia coli O157:H7 within the apoplast of edible plants, spinach and lettuce, compared with the model species Nicotiana benthamiana.
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DOI：
10.1111/1751-7915.12596
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发表时间：
2017-05
影响因子：
5.7
通讯作者：
Holden NJ
中科院分区：
文献类型：
--
作者：
Wright KM;Crozier L;Marshall J;Merget B;Holmes A;Holden NJ
食源性细菌内化到新鲜农产品植物的可食用部分代表了严重的健康风险。因此，在与爆发相关的两个物种菠菜（菠菜）和莴苣（莴苣）中评估了致孢原性大肠杆菌O 157：H7分离株Sakai的内化，并与模式物种本塞姆氏烟草进行了比较。内化发生在菠菜和生菜的叶和根中，整个10天的时间过程。植物种类、组织类型和接种剂量都影响结果。低接种剂量（~102 CFU）与光学显微镜成像的组合突出了内生大肠杆菌O 157：H7 Sakai命运的显著差异。在新鲜的农产品物种中，细菌生长受到限制，但活细胞持续超过20天，而本氏烟草的生长增加> 400倍（~2.5 Log 10）。集落形成发生在表皮细胞和叶肉细胞附近或靠近本氏烟草的维管束，并且包含生物膜基质的组分，包括卷曲表达和诱导、细胞外DNA和有限的纤维素存在。总之，这些数据表明，内在化是作物生产中的一个相关问题，需要将作物物种和组织视为食品安全风险参数。
Internalization of food‐borne bacteria into edible parts of fresh produce plants represents a serious health risk. Therefore, internalization of verocytotoxigenic E. coli O157:H7 isolate Sakai was assessed in two species associated with outbreaks, spinach (Spinacia oleracea) and lettuce (Lactuca sativa) and compared to the model species Nicotiana benthamiana. Internalization occurred in the leaves and roots of spinach and lettuce throughout a 10 day time‐course. The plant species, tissue type and inoculum dose all impacted the outcome. A combination of low inoculum dose (~102 CFU) together with light microscopy imaging highlighted marked differences in the fate of endophytic E. coli O157:H7 Sakai. In the fresh produce species, bacterial growth was restricted but viable cells persisted over 20 days, whereas there was > 400‐fold (~2.5 Log10) increase in growth in N. benthamiana. Colony formation occurred adjacent to epidermal cells and mesophyll cells or close to vascular bundles of N. benthamiana and contained components of a biofilm matrix, including curli expression and elicitation, extracellular DNA and a limited presence of cellulose. Together the data show that internalization is a relevant issue in crop production and that crop species and tissue need to be considered as food safety risk parameters.