Flagellated but Not Hyperfimbriated Salmonella enterica Serovar Typhimurium Attaches to and Forms Biofilms on Cholesterol-Coated Surfaces
Flagellated but Not Hyperfimbriated Salmonella enterica Serovar Typhimurium Attaches to and Forms Biofilms on Cholesterol-Coated Surfaces
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DOI：
10.1128/jb.01620-09
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发表时间：
2010-06-01
影响因子：
3.2
通讯作者：
Gunn, John S.
中科院分区：
文献类型：
--
作者：
Crawford, Robert W.;Reeve, Kristin E.;Gunn, John S.
无症状的慢性肠炎沙门氏菌血清型伤寒带菌者发生在富含胆汁的胆囊，并常伴有胆固醇胆结石。我们之前已经证明，沙门氏菌在体外人类胆结石和胆固醇涂层表面形成生物膜，胆汁诱导的胆固醇胆结石生物膜的形成促进胆囊定植和载体状态的维持。对肠链球菌血清型鼠伤寒菌随机转座子突变体进行了筛选，发现其在胆固醇包被的艾氏管上的粘附和生物膜形成受损，而在玻璃和塑料表面则没有。我们鉴定出49个具有这种表型的突变体。结果表明，参与鞭毛生物合成和结构的基因主要介导了对胆固醇的附着。随后的分析表明，在胆汁存在的情况下，鞭毛细丝的存在增强了结合和生物膜的形成，而鞭毛的运动和1型细丝的表达并不重要。用改良酶联免疫吸附试验（ELISA）纯化的沙门氏菌鞭毛蛋白表明，FliC是介导与胆固醇结合的关键亚基。这些研究提供了更好地了解生物膜形成过程中的早期事件，特别是沙门氏菌如何与胆固醇结合，并提出了可能减轻胆固醇胆结石和慢性携带者状态的生物膜形成的治疗靶点。
The asymptomatic, chronic carrier state of Salmonella enterica serovar Typhi occurs in the bile-rich gallbladder and is frequently associated with the presence of cholesterol gallstones. We have previously demonstrated that salmonellae form biofilms on human gallstones and cholesterol-coated surfaces in vitro and that bile-induced biofilm formation on cholesterol gallstones promotes gallbladder colonization and maintenance of the carrier state. Random transposon mutants of S. enterica serovar Typhimurium were screened for impaired adherence to and biofilm formation on cholesterol-coated Eppendorf tubes but not on glass and plastic surfaces. We identified 49 mutants with this phenotype. The results indicate that genes involved in flagellum biosynthesis and structure primarily mediated attachment to cholesterol. Subsequent analysis suggested that the presence of the flagellar filament enhanced binding and biofilm formation in the presence of bile, while flagellar motility and expression of type 1 fimbriae were unimportant. Purified Salmonella flagellar proteins used in a modified enzyme-linked immunosorbent assay (ELISA) showed that FliC was the critical subunit mediating binding to cholesterol. These studies provide a better understanding of early events during biofilm development, specifically how salmonellae bind to cholesterol, and suggest a target for therapies that may alleviate biofilm formation on cholesterol gallstones and the chronic carrier state.