Investigating the role of conserved signaling modules in medically important Acinetobacter species

项目总结 医学上重要的不动杆菌物种是机会细菌病原体，可导致 这种疾病是住院患者的毁灭性疾病，是美国约2%的医院感染的原因。 这些物种正在成为世界范围内的公共健康威胁，因为它们倾向于表现出多药或 甚至，熊猫抵抗。因此，我们迫切需要开发新的方法来治疗和预防MDR 不动杆菌感染。对这一进展的关键是详细了解这些物种是如何导致人类 然而，关于不动杆菌感染的发病机制仍有许多需要了解的地方。重要的是 恩格尔实验室和其他人已经在铜绿假单胞菌中鉴定出三种系统，另一种重要的 机会性病原体，在与表面接触时协同激活毒力程序。这些 系统包括IV型菌毛(TFP)、CHP化学传感系统和cAMP/Vfr轴。加在一起，这些 模块调节抽动运动和&gt；200毒力基因的表达，例如II型分泌系统。 耐人寻味的是，铜绿假单胞菌重新调整用途，并将三个不同的模块组合在一起，以调节急性 在其他细菌中，TFP和cAMP/Vfr轴控制其他过程时，毒力程序。来测试一下 其他细菌利用相似的成分和相似的电路，恩格尔实验室进行了生物信息学分析 以确定这些模块是否保守并一起存在于其他细菌中。利息很高 发现医学上重要的不动杆菌物种编码所有这三个模块的同源物。 鉴于不动杆菌和铜绿假单胞菌在生活方式上的显著相似性，包括它们的能力 为了在不同的环境中生存并在人类中引起类似的疾病，我假设这三个 系统协调起作用，调节致病不动杆菌在不同物种中生存的能力。 并导致人类疾病。在目标1中，我将使用细菌遗传学、生化、 和创新的显微镜分析，以建立不动杆菌CHP系统的功能输出，并 确定它是否与TFP和CAMP/Vfr模块互连。在目标2中，我将利用转录 识别受不动杆菌Vfr转录调节因子调控的毒力基因和 阐明Vfr激活是否取决于TFP和CHP系统模块。总而言之，这些目标将允许 我来确定TFP、CHP化学传感系统和cAMP/Vfr模块是否协同工作 调节不动杆菌的毒力。这些研究可能会确定开发新抗生素的新靶点， 它们还可能提供对具有重要医学意义的生理学和细胞生物学的更好理解 不动杆菌属。

Project summary Medically important Acinetobacter species are opportunistic bacterial pathogens that can cause devastating disease in hospitalized patients and are responsible for ~2% of nosocomial infections in the US. These species are emerging as a public health threat worldwide due to their tendency to exhibit multidrug-, or even, pandrug-resistance. Therefore, we urgently need to develop new methods to treat and prevent MDR Acinetobacter infections. Critical for this advance is a detailed understanding of how these species cause human disease; however, much remains to be learned about the pathogenesis of Acinetobacter infections. Importantly, The Engel lab and others have identified three systems in Pseudomonas aeruginosa, another important opportunistic pathogen, that coordinately activate a virulence program in response to surface contact. These systems include the type IV pilus (TFP), the Chp chemosensory system, and the cAMP/Vfr axis. Together, these modules regulate twitching motility and expression of >200 virulence genes, such as the type II secretion system. It is intriguing that P. aeruginosa repurposed and combined together three distinct modules to regulate an acute virulence program when in other bacteria the TFP and the cAMP/Vfr axis control other processes. To test whether other bacteria utilize similar components and similar circuitry, the Engel lab performed a bioinformatics analysis to determine whether these modules were conserved and present together in other bacteria. Of high interest was the finding that medically important Acinetobacter species encode homologs of all three of these modules. Given the remarkable similarity in the lifestyles of Acinetobacter species and P. aeruginosa, including their ability to survive in diverse environments as well as to cause similar diseases in humans, I hypothesize that these three systems function coordinately to regulate the ability of a pathogenic Acinetobacter species to survive in diverse environments and to cause human disease. In Aim 1, I will use a combination of bacterial genetics, biochemical, and innovative microscopy assays to establish the functional outputs of the Acinetobacter Chp system and to determine if it is interconnected to the TFP and cAMP/Vfr modules. In Aim 2, I will make use of transcriptomic technologies to identify the virulence genes regulated by the Acinetobacter Vfr transcriptional regulator and to elucidate if Vfr activation depends on the TFP and Chp system modules. Taken together, these aims will allow me to determine whether the TFP, the Chp chemosensory system, and the cAMP/Vfr modules work together to regulate virulence in Acinetobacter species. These studies may identify new targets to develop novel antibiotics, and they might also provide a better understanding of the physiology and cell biology of medically important Acinetobacter species.