Increased Transcription of the Phosphate-Specific Transport System of Escherichia coli O157:H7 after Exposure to Sodium Benzoate
Increased Transcription of the Phosphate-Specific Transport System of Escherichia coli O157:H7 after Exposure to Sodium Benzoate
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DOI：
10.4315/0362-028x-73.5.819
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发表时间：
2010-05-01
影响因子：
2
通讯作者：
Golden, David A.
中科院分区：
文献类型：
--
作者：
Critzer, Faith J.;D'Souza, Doris H.;Golden, David A.
苯甲酸钠是饮料和果汁中广泛使用的一种食品抗菌剂。应用基因芯片技术研究了大肠杆菌O157：H7对0.5%(wt/ol)苯甲酸钠的转录反应。将生长在150mlLuria-Bertani肉汤中的E.colt O157：H7分别暴露于0%(对照)和0.5%苯甲酸钠。每个处理重复并在0(暴露后立即)、5、15、30和60分钟取样。提取总RNA，用E.Coli2.0基因芯片进行分析。使用JProGO软件确定受苯甲酸钠暴露影响的重要本体类别。磷酸盐特定转运(PST)系统在磷酸盐受限的条件下将无机磷酸盐输送到细菌细胞中。PST系统被发现高度上调。在暴露于苯甲酸钠的短短5分钟后，PST系统的表达增加；在5、15、30和60分钟时，PstS、PSTA、PstB和PSTC基因的表达上调了一倍以上(线性范围)。其他几个外排系统，如AcrAB-TolC的表达也增加。在这些胁迫适应条件下，PST系统可能起到外流泵的作用，并增加磷的运输，以帮助DNA、RNA、ATP和磷脂的产生。了解大肠杆菌O157：H7在抗菌剂暴露下的适应情况，对于更好地了解和实施抑制或控制其在食品中生存的方法至关重要。
Sodium benzoate is a widely used food antimicrobial in drinks and fruit juices. A microarray study was conducted to determine the transcriptional response of Escherichia colt O157:H7 to 0.5% (wt/vol) sodium benzoate. E. colt O157:H7 grown in 150 ml of Luria-Bertani broth was exposed to 0% (control) and 0.5% sodium benzoate. Each treatment was duplicated and sampled at 0 (immediately after exposure), 5, 15, 30, and 60 min. Total RNA was extracted and analyzed with E. coli 2.0 Gene Chips. Significant ontology categories affected by sodium benzoate exposure were determined with JProGO software. The phosphate-specific transport (Pst) system transports inorganic phosphate into bacterial cells, under phosphate-limited conditions. The Pst system was found to be highly upregulated. Increased expression of the Pst system was observed after the short 5 min of exposure to sodium benzoate; pstS, pstA, pstB, and pstC genes were upregulated more than twofold (linear scale) at 5, 15, 30, and 60 min. Increased expression of several other efflux systems, such as AcrAB-TolC, was also observed. The Pst system may act as an efflux pump under these stress-adapted conditions, as well as increase transport of phosphorus to aid in DNA, RNA, ATP, and phospholipid production. Understanding adaptations of Escherichia colt O157:H7 under antimicrobial exposure is essential to better understand and implement methods to inhibit or control its survival in foods.