Biofilms of enteric bacteria are highly complex, with multiple components that interact to fortify the biofilm matrix. Within biofilms of enteric bacteria such as Escherichia coli and Salmonella species, the main component of the biofilm is amyloid curli. Other constituents include cellulose, extracellular DNA, O antigen, and various surface proteins, including BapA. Only recently, the roles of these components in the formation of the enteric biofilm individually and in consortium have been evaluated. In addition to enhancing the stability and strength of the matrix, the components of the enteric biofilm influence bacterial virulence and transmission. Most notably, certain components of the matrix are recognized as pathogen-associated molecular patterns. Systemic recognition of enteric biofilms leads to the activation of several proinflammatory innate immune receptors, including the Toll-like receptor 2 (TLR2)/TLR1/CD14 heterocomplex, TLR9, and NLRP3. In the model of Salmonella enterica serovar Typhimurium, the immune response to curli is site specific. Although a proinflammatory response is generated upon systemic presentation of curli, oral administration of curli ameliorates the damaged intestinal epithelial barrier and reduces the severity of colitis. Furthermore, curli (and extracellular DNA) of enteric biofilms potentiate the autoimmune disease systemic lupus erythematosus (SLE) and promote the fibrillization of the pathogenic amyloid α-synuclein, which is implicated in Parkinson's disease. Homologues of curli-encoding genes are found in four additional bacterial phyla, suggesting that the biomedical implications involved with enteric biofilms are applicable to numerous bacterial species.

中文翻译：

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内外含卷曲的肠生物膜：基质组成，免疫识别和疾病影响。

肠细菌的生物膜非常复杂，具有相互作用的多种成分以强化生物膜基质。在诸如大肠杆菌和沙门氏菌等肠细菌的生物膜中，生物膜的主要成分是卷曲淀粉样蛋白。其他成分包括纤维素，细胞外DNA，O抗原和各种表面蛋白，包括BapA。仅在最近，才评估了这些成分在肠内生物膜的形成以及在联合体中的作用。除增强基质的稳定性和强度外，肠溶生物膜的成分还会影响细菌的毒力和传播。最值得注意的是，基质的某些成分被认为是病原体相关的分子模式。肠道生物膜的系统性识别导致几种促炎性先天免疫受体的激活，包括Toll样受体2（TLR2）/ TLR1 / CD14异源复合物，TLR9和NLRP3。在小肠沙门氏菌血清鼠伤寒沙门氏菌模型中，对curli的免疫反应是位点特异性的。尽管在全身性出现卷曲时产生促炎反应，但是口服给予卷曲可改善受损的肠上皮屏障并降低结肠炎的严重性。此外，肠生物膜的卷曲（和细胞外DNA）可增强自身免疫性疾病系统性红斑狼疮（SLE）并促进致病性淀粉样蛋白α-突触核蛋白的原纤维化，这与帕金森氏病有关。在另外四个细菌门中发现了卷曲编码基因的同源物，