Influence of Curli expression by Escherichia coli O157:H7 on the cell's overall hydrophobicity, charge, and ability to attach to lettuce
Influence of Curli expression by Escherichia coli O157:H7 on the cell's overall hydrophobicity, charge, and ability to attach to lettuce
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DOI：
10.4315/0362-028x-70.6.1339
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发表时间：
2007-06-01
影响因子：
2
通讯作者：
Kniel, Kalmia E.
中科院分区：
文献类型：
--
作者：
Boyer, Renee R.;Sumner, Susan S.;Kniel, Kalmia E.
Curli纤维是一些大肠杆菌细胞对环境刺激的反应而产生的。这些细胞外蛋白增强了细胞在各种非生物表面形成生物膜的能力。大肠杆菌O157:H7细胞很容易附着在各种水果和蔬菜表面。目前尚不清楚卷曲蛋白的表达是否会影响细胞附着产生表面的能力。在这项研究中，研究了curli表达对细胞整体疏水性、电荷和对切生菜和整个生菜表面的附着能力的影响。所有菌株，无论curli表达量如何，都优先附着在生菜的切边上（P < 0.05）。大肠杆菌O157:H7菌株E0018在生菜切片和整片上的产卷细胞数量显著高于不产卷细胞的E0018 (P < 0.05)；大肠杆菌O157:H7菌株43894和43895产生卷曲蛋白的细胞与不产生卷曲蛋白的细胞黏附无显著差异。产卷曲杆菌O157:H7菌株的疏水性显著高于其他菌株（P < 0.01）；然而，没有观察到细胞的疏水特性与生菜附着之间的关联。细胞的总体表面电荷在菌株或卷曲表型之间没有差异。结果表明，大肠杆菌O157:H7菌株的总体疏水性和细胞电荷不影响其对卷心莴苣表面的附着。curli的存在可能不会对大肠杆菌O157:H7细胞的附着产生任何影响。其他因素可能影响大肠杆菌O157:H7附着在植物表面，应进一步检查。
Curli fibers are produced by some Escherichia coli cells in response to environmental stimuli. These extracellular proteins enhance the cell's ability to form biofilms on various abiotic surfaces. E. coli O157:H7 cells readily attach to a variety of fruit and vegetable surfaces. It is not known whether the expression of curli influences the cell's ability to attach to produce surfaces. In this study, the effect of curli expression on the cell's overall hydrophobicity, charge, and ability to attach to cut and whole iceberg lettuce surfaces was examined. All strains, regardless of curli expression, attached preferentially to the cut edges of lettuce (P < 0.05). The curli-producing cells of E. coli O157:H7 strain E0018 attached in significantly greater numbers to both cut and whole lettuce pieces than did the non-curli-producing E0018 cells (P < 0.05); however, no significant attachment differences were observed between the curli-producing and non-curli-producing cells of E. coli O157:H7 strains 43894 and 43895. All curli-producing E. coli O157:H7 strains were significantly more hydrophobic (P < 0.01); however, no association between the cells' hydrophobic characteristics and lettuce attachment was observed. Overall surface charge of the cells did not differ among strains or curli phenotypes. Results indicate that overall hydrophobicity and cell charge in E. coli O157:H7 strains do not influence attachment to iceberg lettuce surfaces. The presence of curli may not have any influence on attachment of E. coli O157:H7 cells to produce items. Additional factors may influence the attachment of E. coli O157:H7 to plant surfaces and should be further examined.