Picozzi Claudia, Antoniani Davide, Vigentini Ileana, Foschino Roberto, Kneifel Wolfgang
FEMS Microbiol Lett. 2017 Jan 1;364(2). doi: 10.1093/femsle/fnw291.
Shiga toxin-producing Escherichia coli (STEC) are recognized as one of the most dangerous foodborne pathogens. The production of Shiga toxins together with intimin protein is among the main virulence factors. However, the ability to form biofilm can protect bacteria against environmental factors (i.e. desiccation, exposure to UV rays, predation, etc.) and sanitization procedures (cleaning, rinsing, chlorination), increasing their survival on food products and in manufacturing plants. Forty-five isolates collected from food and fecal samples were genotyped by pulsed field gel electrophoresis analysis with XbaI restriction enzyme and investigated by searching for toxins (stx1, stx2) and intimin (eae) genes and serogroup (O157, O26, O145, O111, O103 and O104). Afterward, the ability to develop biofilm in microtiter assay and the production of adhesive curli fimbriae and cellulose on agar plates were tested. Our study demonstrated that biofilm formation has a great variability among STEC strains and cannot be related to a specific pulsotype nor even to serogroup or presence of virulence genes.
产志贺毒素大肠杆菌（STEC）被认为是最危险的食源性病原体之一。志贺毒素的产生以及紧密黏附素蛋白是主要的毒力因子。然而，形成生物膜的能力可以保护细菌免受环境因素（如干燥、紫外线照射、捕食等）和卫生程序（清洁、冲洗、氯化）的影响，提高它们在食品和生产工厂中的存活率。通过使用XbaI限制酶进行脉冲场凝胶电泳分析，对从食品和粪便样本中收集的45株分离株进行基因分型，并通过查找毒素（stx1、stx2）和紧密黏附素（eae）基因以及血清型（O157、O26、O145、O111、O103和O104）进行调查。随后，测试了在微量滴定试验中形成生物膜的能力以及在琼脂平板上产生黏附性卷曲菌毛和纤维素的情况。我们的研究表明，STEC菌株之间生物膜形成的差异很大，并且与特定的脉冲型无关，甚至与血清型或毒力基因的存在也无关。
