Nunvar Jaroslav, Hogan Andrew M, Buroni Silvia, Savina Svetlana, Makarov Vadim, Cardona Silvia T, Drevinek Pavel
Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15400 Prague, Czech Republic.
Department of Microbiology, Faculty of Science, University of Manitoba, 213 Buller Building, Winnipeg, MB R3T 2N2, Canada.
Antibiotics (Basel). 2019 Sep 21;8(4):159. doi: 10.3390/antibiotics8040159.
Bacteria of the complex (Bcc) are associated with significant decline of lung functions in cystic fibrosis patients. Bcc infections are virtually impossible to eradicate due to their irresponsiveness to antibiotics. The 2-thiocyanatopyridine derivative 11026103 is a novel, synthetic compound active against . To characterize mechanisms of resistance to 11026103, was subjected to chemical mutagenesis, followed by whole genome sequencing. Parallel mutations in resistant isolates were localized in a regulatory protein of the efflux system Resistance-Nodulation-Division (RND)-9 (BCAM1948), RNA polymerase sigma factor (BCAL2462) and its cognate putative anti-sigma factor (BCAL2461). Transcriptomic analysis identified positive regulation of a major facilitator superfamily (MFS) efflux system BCAL1510-1512 by BCAL2462. Artificial overexpression of both efflux systems increased resistance to the compound. The effect of 11026103 on was analyzed by RNA-Seq and a competitive fitness assay utilizing an essential gene knockdown mutant library. 11026103 exerted a pleiotropic effect on transcription including profound downregulation of cluster of orthologous groups (COG) category "Translation, ribosomal structure, and biogenesis". The competitive fitness assay identified many genes which modulated susceptibility to 11026103. In summary, 11026103 exerts a pleiotropic cellular response in which can be prevented by efflux system-mediated export.
洋葱伯克霍尔德菌复合体（Bcc）与囊性纤维化患者的肺功能显著下降有关。由于Bcc对抗生素无反应，其感染几乎无法根除。2-硫氰基吡啶衍生物11026103是一种对洋葱伯克霍尔德菌有效的新型合成化合物。为了表征对11026103的耐药机制，对洋葱伯克霍尔德菌进行了化学诱变，随后进行全基因组测序。耐药菌株中的平行突变定位于外排系统耐药-结瘤-分裂（RND）-9（BCAM1948）的一种调节蛋白、RNA聚合酶σ因子（BCAL2462）及其同源假定抗σ因子（BCAL2461）中。转录组分析确定了BCAL2462对主要易化子超家族（MFS）外排系统BCAL1510-1512的正向调控。两种外排系统的人工过表达均增加了对该化合物的耐药性。通过RNA测序和利用必需基因敲除突变体文库的竞争适应性试验分析了11026103对洋葱伯克霍尔德菌的影响。11026103对转录产生多效性影响，包括直系同源基因簇（COG）类别“翻译、核糖体结构和生物发生”的显著下调。竞争适应性试验确定了许多调节对11026103敏感性的基因。总之，11026103在洋葱伯克霍尔德菌中产生多效性细胞反应，这种反应可通过外排系统介导的输出加以阻止。
