Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2010 Jun;73(6):1038-46. doi: 10.4315/0362-028x-73.6.1038.
Shiga toxin-producing Escherichia coli (STEC) is known to have several defense mechanisms, one of which is the production of extracellular substances including cellulose. The goal of this study was to prepare pairs of STEC cultures for use in future studies designed to address the role of cellulose in protecting the cells of STEC for survival under adverse environmental conditions. Cells of STEC deficient in cellulose production were separated from cellulose-proficient wild-type cells. The identities of the two types of cells were confirmed using serotyping and pulsed-field gel electrophoresis (PFGE). Selected growth characteristics of the two types of cells were determined using three phenotype microarray plates, PM9, PM10, and PM11. The cellulose-deficient and cellulose-proficient cells in each STEC pair shared the same serotype and PFGE profile. The deficiency in cellulose production did not significantly (P > 0.05) affect the growth characteristics of STEC cells under 191 of the 210 tested growth conditions. Significant differences in growth between the two types of cells were observed only in the presence of two antibiotics, a short chain fatty acid, and high concentrations of osmolytes, as well as under extreme acidic and alkaline pH. These results suggest that deficiency in cellulose production did not alter the serological property, PFGE profile, and growth characteristics of selected STEC strains under optimal growth conditions. The STEC strains and their cellulose-deficient derivates could be useful for studying the role of cellulose in protecting the cells of STEC for survival under adverse environmental conditions.
产志贺毒素大肠杆菌（STEC）已知具有几种防御机制，其中之一是产生包括纤维素在内的细胞外物质。本研究的目的是准备配对的 STEC 培养物，用于未来的研究，以解决纤维素在保护 STEC 细胞在不利环境条件下生存中的作用。从纤维素高产野生型细胞中分离出缺乏纤维素产生能力的 STEC 细胞。使用血清分型和脉冲场凝胶电泳（PFGE）确认两种类型细胞的身份。使用三种表型微阵列板 PM9、PM10 和 PM11 确定两种类型细胞的选定生长特性。每个 STEC 对中的纤维素缺陷和纤维素丰富的细胞具有相同的血清型和 PFGE 图谱。纤维素产生的缺乏并没有显著（P>0.05）影响 210 种测试生长条件中的 191 种条件下 STEC 细胞的生长特性。仅在存在两种抗生素、短链脂肪酸和高浓度渗透物以及极端酸性和碱性 pH 条件下，两种细胞类型之间的生长存在显著差异。这些结果表明，在最佳生长条件下，纤维素产生的缺乏并没有改变选定 STEC 菌株的血清学特性、PFGE 图谱和生长特性。STEC 菌株及其纤维素缺陷衍生株可用于研究纤维素在保护 STEC 细胞在不利环境条件下生存中的作用。
