A supplemented soft agar chemotaxis assay demonstrates the Helicobacter pylori chemotactic response to zinc and nickel.
A supplemented soft agar chemotaxis assay demonstrates the Helicobacter pylori chemotactic response to zinc and nickel.
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DOI：
10.1099/mic.0.062877-0
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发表时间：
2013
期刊：
影响因子：
1.5
通讯作者：
L. Sanders;T. Andermann;K. Ottemann
中科院分区：
文献类型：
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作者：
L. Sanders;T. Andermann;K. Ottemann
定向运动或趋化性是幽门螺杆菌在胃中建立感染所必需的，尽管这种细菌的趋化性反应的全部谱尚不清楚。本文报道了H.幽门螺杆菌对作为引诱剂的锌和作为驱避剂的镍有反应。为了得出这一结论，我们采用了基于细菌逆转的时间趋化性测定和补充的软琼脂空间测定。我们使用先前描述的化学排斥剂酸改进了时间测定，并发现H。幽门螺杆菌需要富含血清的培养基以维持最佳的游泳运动性。令人惊讶的是，我们发现一些菌株响应酸作为引诱剂，TlpC化学感受器与酸是否被感知为引诱剂或排斥剂。使用这种相同的测定，我们检测到弱驱避反应镍和铜，和不同的锌。因此，我们开发了一种替代的空间趋化性试验，称为补充软琼脂试验，其利用补充有供试化合物的软琼脂培养基。对于大肠杆菌，引诱剂丝氨酸减缓了细菌的整体迁移，而驱避剂镍增加了整体迁移的速度。In H. pylori，我们检测到用双倍胰蛋白胨培养基以及锌减缓迁移，这与引诱剂反应一致。相反，镍增加迁移，与排斥一致。
Directed motility, or chemotaxis, is required for Helicobacter pylori to establish infection in the stomach, although the full repertoire of this bacterium's chemotactic responses is not yet known. Here we report that H. pylori responds to zinc as an attractant and nickel as a repellent. To reach this conclusion, we employed both a temporal chemotaxis assay based on bacterial reversals and a supplemented soft agar spatial assay. We refined the temporal assay using a previously described chemorepellent, acid, and found that H. pylori requires rich media with serum to maintain optimal swimming motility. Surprisingly, we found that some strains respond to acid as an attractant, and that the TlpC chemoreceptor correlated with whether acid was sensed as an attractant or repellent. Using this same assay, we detected weak repellent responses to nickel and copper, and a varied response to zinc. We thus developed an alternative spatial chemotactic assay called the supplemented soft agar assay, which utilizes soft agar medium supplemented with the test compound. With Escherichia coli, the attractant serine slowed overall bacterial migration, while the repellent nickel increased the speed of overall migration. In H. pylori we detected slowed migration with doubled tryptone media, as well as zinc, consistent with an attractant response. In contrast, nickel increased migration, consistent with repulsion.