Oh Euna, Andrews Katelyn J, Jeon Byeonghwa
School of Public Health, University of Alberta, Edmonton, AB, Canada.
Front Microbiol. 2018 Jun 6;9:1204. doi: 10.3389/fmicb.2018.01204. eCollection 2018.
is a leading foodborne pathogen worldwide. Biofilm formation is an important survival mechanism that sustains the viability of under harsh stress conditions. Iron affects biofilm formation in some other bacteria; however, the effect of iron on biofilm formation has not been investigated in . In this study, we discovered that ferrous (Fe) and ferric (Fe) iron stimulated biofilm formation in . The sequestration of iron with an iron chelator prevented the iron-mediated biofilm stimulation. The level of total reactive oxygen species (ROS) in biofilms was increased by iron. However, the supplementation with an antioxidant prevented the total ROS level from being increased in biofilms by iron and also inhibited iron-mediated biofilm stimulation in . This suggests that iron promotes biofilm formation through oxidative stress. Based on the results of fluorescence microscopic analysis, Fe and Fe enhanced both microcolony formation and biofilm maturation. The levels of extracellular DNA and polysaccharides in biofilms were increased by iron supplementation. The effect of iron on biofilm formation was also investigated with 70 isolates from raw chicken. Regardless of the inherent levels of biofilm formation, iron stimulated biofilm formation in all tested strains; however, there were strain variations in iron concentrations affecting biofilm formation. The biofilm formation of 92.9% (65 of 70) strains was enhanced by either 40 μM Fe or 20 μM Fe or both (the iron concentrations that enhanced biofilm formation in NCTC 11168), whereas different iron concentrations were required to promote biofilms in the rest of the strains. The findings in this study showed that Fe and Fe contributed to the stimulation of biofilm formation in through oxidative stress.
是全球主要的食源性病原体。生物膜形成是一种重要的生存机制，可在恶劣应激条件下维持其生存能力。铁会影响其他一些细菌的生物膜形成；然而，铁对生物膜形成的影响尚未在中进行研究。在本研究中，我们发现亚铁（Fe）和铁（Fe）刺激了生物膜的形成。用铁螯合剂螯合铁可防止铁介导的生物膜刺激。铁会增加生物膜中总活性氧（ROS）的水平。然而，补充抗氧化剂可防止铁使生物膜中的总ROS水平升高，并且还抑制了铁介导的生物膜刺激。这表明铁通过氧化应激促进生物膜形成。基于荧光显微镜分析结果，Fe和Fe增强了微菌落形成和生物膜成熟。补充铁会增加生物膜中细胞外DNA和多糖的水平。还对70株来自生鸡肉的分离株研究了铁对生物膜形成的影响。无论生物膜形成的固有水平如何，铁均刺激了所有测试菌株中的生物膜形成；然而，影响生物膜形成的铁浓度存在菌株差异。92.9%（70株中的65株）菌株的生物膜形成通过40μM Fe或20μM Fe或两者（在NCTC 11168中增强生物膜形成的铁浓度）得到增强，而其余菌株促进生物膜形成则需要不同的铁浓度。本研究结果表明，Fe和Fe通过氧化应激促进了生物膜的形成。
