Ramos Pablo Ivan Pereira, Custódio Márlon Grégori Flores, Quispe Saji Guadalupe Del Rosario, Cardoso Thiago, da Silva Gisele Lucchetti, Braun Graziela, Martins Willames M B S, Girardello Raquel, de Vasconcelos Ana Tereza Ribeiro, Fernández Elmer, Gales Ana Cristina, Nicolás Marisa Fabiana
Laboratório Nacional de Computação Científica, Petrópolis, Rio de Janeiro, Brazil.
Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
BMC Genomics. 2016 Oct 25;17(Suppl 8):737. doi: 10.1186/s12864-016-3070-y.
The emergence of multidrug-resistant Klebsiella pneumoniae is a major public health concern. Many K. pneumoniae infections can only be treated when resorting to last-line drugs such as polymyxin B (PB). However, resistance to this antibiotic is also observed, although insufficient information is described on its mode of action as well as the mechanisms used by resistant bacteria to evade its effects. We aimed to study PB resistance and the influence of abiotic stresses in a clinical K. pneumoniae strain using whole transcriptome profiling.
We sequenced 12 cDNA libraries of K. pneumoniae Kp13 bacteria, from two biological replicates of the original strain Kp13 (Kp13) and five derivative strains: induced high-level PB resistance in acidic pH (Kp13), magnesium deprivation (Kp13), high concentrations of calcium (Kp13) and iron (Kp13), and a control condition with PB (Kp13). Our results show the involvement of multiple regulatory loci that differentially respond to each condition as well as a shared gene expression response elicited by PB treatment, and indicate the participation of two-regulatory components such as ArcA-ArcB, which could be involved in re-routing the K. pneumoniae metabolism following PB treatment. Modules of co-expressed genes could be determined, which correlated to growth in acid stress and PB exposure. We hypothesize that polymyxin B induces metabolic shifts in K. pneumoniae that could relate to surviving against the action of this antibiotic.
We obtained whole transcriptome data for K. pneumoniae under different environmental conditions and PB treatment. Our results supports the notion that the K. pneumoniae response to PB exposure goes beyond damaged membrane reconstruction and involves recruitment of multiple gene modules and intracellular targets.
多重耐药肺炎克雷伯菌的出现是一个重大的公共卫生问题。许多肺炎克雷伯菌感染只有在使用多粘菌素B（PB）等最后一线药物时才能得到治疗。然而，尽管关于其作用方式以及耐药细菌逃避其作用的机制的信息不足，但对这种抗生素的耐药性也已被观察到。我们旨在使用全转录组分析研究临床肺炎克雷伯菌菌株对PB的耐药性以及非生物胁迫的影响。
我们对肺炎克雷伯菌Kp13细菌的12个cDNA文库进行了测序，这些文库来自原始菌株Kp13（Kp13）的两个生物学重复以及五个衍生菌株：在酸性pH值下诱导产生高水平PB耐药性（Kp13）、缺镁（Kp13）、高浓度钙（Kp13）和铁（Kp13），以及PB处理的对照条件（Kp13）。我们的结果表明，多个调控位点参与其中，它们对每种条件有不同的反应，以及PB处理引发的共同基因表达反应，并表明双组分调控元件如ArcA - ArcB的参与，这可能参与了PB处理后肺炎克雷伯菌代谢的重新定向。可以确定共表达基因模块，其与酸胁迫和PB暴露下的生长相关。我们假设多粘菌素B在肺炎克雷伯菌中诱导代谢转变，这可能与抵抗这种抗生素的作用而存活有关。
我们获得了肺炎克雷伯菌在不同环境条件和PB处理下的全转录组数据。我们的结果支持这样一种观点，即肺炎克雷伯菌对PB暴露的反应不仅仅是受损膜的重建，还涉及多个基因模块和细胞内靶点的募集。
