Department of Medical Biomaterials Engineering, Kangwon National University, Chuncheon, Gangwon, Korea.
Lett Appl Microbiol. 2012 Oct;55(4):274-82. doi: 10.1111/j.1472-765X.2012.03288.x. Epub 2012 Jul 31.
To characterize the cellular and molecular properties of Salmonella Typhimurium exposed to antimicrobials in association with physicochemical property, biofilm formation ability and gene expression patterns.
The antimicrobial susceptibilities against Salmonella Typhimurium were evaluated to determine the MICs of allyl isothiocyanate (AITC), thymol, eugenol and polyphenol. Cell surface hydrophobicity, aggregation and biofilm formation assays were conducted to assess the physicochemical properties of Salm. Typhimurium treated with sublethal concentrations (SLC(2D) ) of antimicrobials. The expression patterns of adhesion-related genes (adrA, csgD, fimA and lpfE), virulence-related genes (hilA and stn) and efflux-related genes (acrA, acrB, ompD and tolC) were evaluated by real-time RT-PCR. Thymol exhibited the highest antimicrobial activity against Salm. Typhimurium planktonic, biofilm and dispersed cells, showing 0·18, 0·96 and 0·42 mg ml(-1) of SLC(2D) values, respectively. The antimicrobial-treated Salm. Typhimurium showed low hydrophobicity. The highest auto-aggregation ability (67%) of polyphenol-treated Salm. Typhimurium was positively associated with the enhanced ability to form biofilms. The csgD, fimA, hilA and lpfE genes were up-regulated in the polyphenol-treated Salm. Typhimurium planktonic and biofilm cells.
The results suggest that the antimicrobial resistance and virulence potential varied depending on the physiological states of Salm. Typhimurium during the transition from planktonic to biofilm cell growth.
This study can expand our understanding of cellular and molecular mechanisms of biofilm formation and also provide useful information for reducing biofilm-associated virulence potential.
研究鼠伤寒沙门氏菌在接触抗生素时的细胞和分子特性，同时研究其理化特性、生物膜形成能力和基因表达模式。
评估鼠伤寒沙门氏菌对各种抗生素的药敏性，以确定丙烯基异硫氰酸酯（AITC）、百里香酚、丁香酚和多酚的最低抑菌浓度（MIC）。采用亚致死浓度（SLC（2D））抗生素处理鼠伤寒沙门氏菌，进行细胞表面疏水性、聚集和生物膜形成试验，以评估其理化特性。通过实时 RT-PCR 评估粘附相关基因（adrA、csgD、fimA 和 lpfE）、毒力相关基因（hilA 和 stn）和外排相关基因（acrA、acrB、ompD 和 tolC）的表达模式。百里香酚对浮游、生物膜和分散细胞的鼠伤寒沙门氏菌表现出最强的抗菌活性，其 SLC（2D）值分别为 0.18、0.96 和 0.42 mg ml(-1)。经抗生素处理的鼠伤寒沙门氏菌疏水性较低。多酚处理的鼠伤寒沙门氏菌的自动聚集能力（67%）最高，与增强的生物膜形成能力呈正相关。多酚处理的鼠伤寒沙门氏菌浮游和生物膜细胞中的 csgD、fimA、hilA 和 lpfE 基因上调。
结果表明，鼠伤寒沙门氏菌从浮游状态向生物膜细胞生长的转变过程中，其抗生素耐药性和毒力潜能因生理状态而异。
本研究可以扩展我们对生物膜形成的细胞和分子机制的理解，并为降低与生物膜相关的毒力潜能提供有用信息。
