Klerks M M, van Gent-Pelzer M, Franz E, Zijlstra C, van Bruggen A H C
Wageningen University and Research Centre, Plant Research International BV, Droevendaalsesteeg 1, 6709 PB Wageningen, The Netherlands.
Appl Environ Microbiol. 2007 Aug;73(15):4905-14. doi: 10.1128/AEM.02522-06. Epub 2007 May 18.
This paper describes the physiological and molecular interactions between the human-pathogenic organism Salmonella enterica serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of S. enterica serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of S. enterica serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with S. enterica serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of S. enterica serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that Salmonella spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed.
本文描述了人类病原菌肠炎沙门氏菌都柏林血清型与市售迷你罗马生菜品种坦布罗之间的生理和分子相互作用。首先确定了肠炎沙门氏菌都柏林血清型与生菜植株的关联，这表明在植株外部和内部均存在大量该菌。高效表面消毒（99.81%）后仍有显著残留浓度，以及在生菜根 - 茎过渡区横切面中对肠炎沙门氏菌都柏林血清型进行荧光显微镜观察，均证明了该菌在植株内部的存在。与未被定殖的植株相比，被肠炎沙门氏菌都柏林血清型定殖后的植株生物量显著降低。除了生理反应外，通过cDNA扩增片段长度多态性分析进行的转录组分析也明确显示了未被定殖和被定殖的生菜植株之间存在差异基因表达谱。从中选择一般和差异表达的基因并通过序列分析进行鉴定，随后通过逆转录 - PCR展示特定基因随时间的表达谱。对表达基因的功能分组表明，植株的定殖与致病性相关基因表达的增加之间存在相关性。这项研究表明，生菜植株在生理和分子水平上对肠炎沙门氏菌都柏林血清型的存在做出反应，表现为生长减少和致病性相关基因的同时表达。此外，还证实了沙门氏菌属能够定殖在生菜植株内部，因此在加工和食用时可能对人类健康构成风险。
