Merry Callie R, Perkins Michael, Mu Lin, Peterson Bridget K, Knackstedt Rebecca W, Weingart Christine L
Case Western University, Cleveland, USA,
Curr Microbiol. 2015 Apr;70(4):556-61. doi: 10.1007/s00284-014-0744-z. Epub 2014 Dec 18.
Two-component systems are important regulatory systems that allow bacteria to adjust to environmental conditions, and in some bacteria are used in pathogenesis. We identified a novel two-component system in Burkholderia cenocepacia, an opportunistic pathogen that causes pneumonia in cystic fibrosis (CF) patients. The putative operon encodes BceS, a sensor kinase, and BceR, a response regulator. Our studies indicated that the bceR mutant showed a statistically significant decrease in protease, swimming motility, and quorum sensing when compared to the wild-type, but there was no significant difference in phospholipase C activity, swarming, and biofilm formation. In addition, the mutant showed a statistically significant reduction in virulence compared to the wild-type using the alfalfa plant model. Examination of the Burkholderia cepacia complex (a group of organisms that are phenotypically similar, but genotypically distinct) revealed that this system is prevalent in B. ambifaria, B. multivorans, B. vietnamiensis and B. dolosa. Interestingly, all these organisms have been associated with CF patients. The collective results indicate that BceSR influences various activities important in Burkholderia physiology and possibly pathogenesis. This information could be important in the design of novel therapeutics for Burkholderia infections.
双组分系统是重要的调节系统，可使细菌适应环境条件，并且在某些细菌中参与致病过程。我们在洋葱伯克霍尔德菌中鉴定出一种新型双组分系统，洋葱伯克霍尔德菌是一种机会致病菌，可在囊性纤维化（CF）患者中引起肺炎。该假定的操纵子编码一种传感激酶BceS和一种反应调节因子BceR。我们的研究表明，与野生型相比，bceR突变体在蛋白酶、游动运动性和群体感应方面显示出统计学上的显著降低，但在磷脂酶C活性、群游和生物膜形成方面没有显著差异。此外，使用苜蓿植物模型时，该突变体与野生型相比显示出统计学上显著的毒力降低。对洋葱伯克霍尔德菌群（一组表型相似但基因型不同的生物体）的检测表明，该系统在栖稻伯克霍尔德菌、多食伯克霍尔德菌、越南伯克霍尔德菌和多杀伯克霍尔德菌中普遍存在。有趣的是，所有这些生物体都与CF患者有关。总体结果表明，BceSR影响伯克霍尔德菌生理学中以及可能在致病过程中重要的各种活动。这些信息对于设计针对伯克霍尔德菌感染的新型疗法可能很重要。
