Clinically relevant fluoroquinolone resistance due to constitutive overexpression of the PatAB ABC transporter in Streptococcus pneumoniae is conferred by disruption of a transcriptional attenuator.
Clinically relevant fluoroquinolone resistance due to constitutive overexpression of the PatAB ABC transporter in Streptococcus pneumoniae is conferred by disruption of a transcriptional attenuator.
复制标题
DOI：
10.1093/jac/dku449
复制
发表时间：
2015-03
期刊：
影响因子：
--
通讯作者：
Piddock LJ
中科院分区：
文献类型：
--
作者：
Baylay AJ;Piddock LJ
在几种不相关的氟喹诺酮耐药实验室突变体和临床分离株中观察到patAB组成性过表达;因此，我们试图确定这种过表达的原因。使用全基因组转化方法研究了两个临床分离株和一个实验室选择的突变株中组成型patAB过表达。为了确定检测到的终止子突变的影响，将WT和突变的patA前导序列克隆到GFP报告基因的上游。最后，对茎环结构中的相对碱基进行突变。我们确定了三个新的突变导致patAB的上调。所有这三个都位于上游区域的patA和影响相同的Rho独立的转录终止子结构。预测每个突变在不同程度上使终止子茎环不稳定，并且预测的终止子稳定性与patAB表达水平之间存在强相关性。使用patA转录的GFP报告基因，这些终止子突变导致下游基因的转录增加。对于一个突变体序列，终止子稳定性可以通过突变茎环结构中的相对碱基来恢复，表明patAB的转录抑制是由终止子茎环结构介导的。这项研究表明，在Rho非依赖性转录终止子结构的突变赋予patAB和氟喹诺酮耐药的过度表达。了解PatAB外排泵的水平是如何调节的，增加了我们对肺炎球菌生物学的了解，以及肺炎球菌如何对各种应激反应，包括抗菌药物。
Constitutive overexpression of patAB has been observed in several unrelated fluoroquinolone-resistant laboratory mutants and clinical isolates; therefore, we sought to identify the cause of this overexpression. Constitutive patAB overexpression in two clinical isolates and a laboratory-selected mutant was investigated using a whole-genome transformation approach. To determine the effect of the detected terminator mutations, the WT and mutated patA leader sequences were cloned upstream of a GFP reporter. Finally, mutation of the opposing base in the stem–loop structure was carried out. We identified three novel mutations causing up-regulation of patAB. All three of these were located in the upstream region of patA and affected the same Rho-independent transcriptional terminator structure. Each mutation was predicted to destabilize the terminator stem–loop to a different degree, and there was a strong correlation between predicted terminator stability and patAB expression level. Using a GFP reporter of patA transcription, these terminator mutations led to increased transcription of a downstream gene. For one mutant sequence, terminator stability could be restored by mutation of the opposing base in the stem–loop structure, demonstrating that transcriptional suppression of patAB is mediated by the terminator stem–loop structure. This study showed that a mutation in a Rho-independent transcriptional terminator structure confers overexpression of patAB and fluoroquinolone resistance. Understanding how levels of the PatAB efflux pump are regulated increases our knowledge of pneumococcal biology and how the pneumococcus can respond to various stresses, including antimicrobials.
登录
查看更多内容
影响因子：
14.9
作者：
Reilman E;Mars RA;van Dijl JM;Denham EL
通讯作者：
Denham EL
影响因子：
16
作者：
Gusarov, I;Nudler, E
通讯作者：
Nudler, E
DOI：
10.1186/1748-7188-6-26
发表时间：
2011-11-24
期刊：
Algorithms for molecular biology : AMB
影响因子：
--
作者：
Lorenz R;Bernhart SH;Höner Zu Siederdissen C;Tafer H;Flamm C;Stadler PF;Hofacker IL
通讯作者：
Hofacker IL
影响因子：
2.1
作者：
Kruegel, Hans;Licht, Andreas;Saluz, Hans-Peter
通讯作者：
Saluz, Hans-Peter
影响因子：
4.9
作者：
Piddock, LJV;Johnson, MM;Pumbwe, L
通讯作者：
Pumbwe, L