IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Torre Sul, Piso 6. Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Microb Pathog. 2010 May;48(5):168-77. doi: 10.1016/j.micpath.2010.02.006. Epub 2010 Mar 3.
Burkholderia cenocepacia is one of the most virulent species of the Burkholderia cepacia complex, a group of bacteria that emerged as important pathogens, especially to cystic fibrosis (CF) patients. In this study, we report the identification and characterization of a mutant strain derived form the CF isolate Burkholderia cenocepacia K56-2, carrying a plasposon insertion in a gene, located in a 3516 bp chromosomal region with an atypical G+C content, encoding a 80 amino acid putative regulatory protein named Pbr. Besides its inability to produce phenazines, the B. cenocepacia K56-2 pbr mutant exhibited a pleiotropic phenotype, including impaired survival to oxidative and osmotic stress, aromatic amino acid and prolonged nutrient starvation periods. In addition, the pbr mutant exhibited decreased virulence the nematode Caenorhabditis elegans. Altogether, our results demonstrate the involvement of Pbr on the regulation of phenazine biosynthesis, and an important role for this regulatory protein on several cellular processes related to stress resistance and virulence.
洋葱伯克霍尔德菌是洋葱伯克霍尔德菌复合体中最具毒力的物种之一，该复合体是一组细菌，已成为重要的病原体，尤其是对囊性纤维化（CF）患者。在这项研究中，我们报告了源自 CF 分离株洋葱伯克霍尔德菌 K56-2 的突变菌株的鉴定和特征，该突变菌株在一个基因中携带质粒插入，该基因位于具有非典型 GC 含量的 3516 bp 染色体区域中，编码一个 80 个氨基酸的推定调节蛋白，命名为 Pbr。除了不能产生吩嗪外，B. cenocepacia K56-2 pbr 突变体还表现出多种表型，包括对氧化和渗透压应激、芳香族氨基酸和延长的营养饥饿期的生存能力下降。此外，pbr 突变体在秀丽隐杆线虫中表现出降低的毒力。总之，我们的结果表明 Pbr 参与了吩嗪生物合成的调节，并且该调节蛋白在与应激抗性和毒力相关的几个细胞过程中发挥着重要作用。
