Tan Michelle S F, Rahman Sadequr, Dykes Gary A
School of Science, Monash University, Bandar Sunway, Selangor, Malaysia.
School of Science, Monash University, Bandar Sunway, Selangor, Malaysia School of Public Health, Curtin University, Perth, Western Australia, Australia
Appl Environ Microbiol. 2015 Nov 13;82(2):680-8. doi: 10.1128/AEM.02609-15. Print 2016 Jan 15.
Minimally processed fresh produce has been implicated as a major source of foodborne microbial pathogens globally. These pathogens must attach to the produce in order to be transmitted. Cut surfaces of produce that expose cell walls are particularly vulnerable. Little is known about the roles that different structural components (cellulose, pectin, and xyloglucan) of plant cell walls play in the attachment of foodborne bacterial pathogens. Using bacterial cellulose-derived plant cell wall models, we showed that the presence of pectin alone or xyloglucan alone affected the attachment of three Salmonella enterica strains (Salmonella enterica subsp. enterica serovar Enteritidis ATCC 13076, Salmonella enterica subsp. enterica serovar Typhimurium ATCC 14028, and Salmonella enterica subsp. indica M4) and Listeria monocytogenes ATCC 7644. In addition, we showed that this effect was modulated in the presence of both polysaccharides. Assays using pairwise combinations of S. Typhimurium ATCC 14028 and L. monocytogenes ATCC 7644 showed that bacterial attachment to all plant cell wall models was dependent on the characteristics of the individual bacterial strains and was not directly proportional to the initial concentration of the bacterial inoculum. This work showed that bacterial attachment was not determined directly by the plant cell wall model or bacterial physicochemical properties. We suggest that attachment of the Salmonella strains may be influenced by the effects of these polysaccharides on physical and structural properties of the plant cell wall model. Our findings improve the understanding of how Salmonella enterica and Listeria monocytogenes attach to plant cell walls, which may facilitate the development of better ways to prevent the attachment of these pathogens to such surfaces.
最少加工的新鲜农产品被认为是全球食源性病原体的主要来源。这些病原体必须附着在农产品上才能传播。暴露细胞壁的农产品切割表面特别容易受到影响。关于植物细胞壁的不同结构成分（纤维素、果胶和木葡聚糖）在食源细菌病原体附着过程中所起的作用，人们了解甚少。利用细菌纤维素衍生的植物细胞壁模型，我们发现单独存在果胶或木葡聚糖会影响三种肠炎沙门氏菌菌株（肠炎沙门氏菌亚种肠炎血清型肠炎沙门氏菌ATCC 13076、肠炎沙门氏菌亚种肠炎血清型鼠伤寒沙门氏菌ATCC 14028和肠炎沙门氏菌亚种印度沙门氏菌M4）以及单核细胞增生李斯特菌ATCC 7644的附着。此外，我们还发现，在两种多糖同时存在的情况下，这种影响会受到调节。使用鼠伤寒沙门氏菌ATCC 14028和单核细胞增生李斯特菌ATCC 7644的两两组合进行的试验表明，细菌对所有植物细胞壁模型的附着取决于各个细菌菌株的特性，并且与细菌接种物的初始浓度不成正比。这项工作表明，细菌的附着并非直接由植物细胞壁模型或细菌的物理化学性质决定。我们认为，沙门氏菌菌株的附着可能受到这些多糖对植物细胞壁模型物理和结构性质影响的作用。我们的研究结果增进了对肠炎沙门氏菌和单核细胞增生李斯特菌如何附着于植物细胞壁的理解，这可能有助于开发更好的方法来防止这些病原体附着于此类表面。
