...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Microbiology >RcsB Contributes to the Distinct Stress Fitness among Escherichia coli O157:H7 Curli Variants of the 1993 Hamburger-Associated Outbreak Strains
【24h】

RcsB Contributes to the Distinct Stress Fitness among Escherichia coli O157:H7 Curli Variants of the 1993 Hamburger-Associated Outbreak Strains

机译：RcsB促成1993年与汉堡相关的暴发菌株的O157：H7卷曲大肠杆菌变异应激适应性

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Curli are adhesive fimbriae of Enterobactericaeae and are involved in surface attachment, cell aggregation, and biofilm formation. We reported previously that curli-producing (C~(+)) variants of E. coli O157:H7 (EcO157) were much more acid sensitive than their corresponding curli-deficient (C~(?)) variants; however, this difference was not linked to the curli fimbriae per se . Here, we investigated the underlying molecular basis of this phenotypic divergence. We identified large deletions in the rcsB gene of C~(+) variants isolated from the 1993 U.S. hamburger-associated outbreak strains. rcsB encodes the response regulator of the RcsCDB two-component signal transduction system, which regulates curli biogenesis negatively but acid resistance positively. Further comparison of stress fitness revealed that C~(+) variants were also significantly more sensitive to heat shock but were resistant to osmotic stress and oxidative damage, similar to C~(?) variants. Transcriptomics analysis uncovered a large number of differentially expressed genes between the curli variants, characterized by enhanced expression in C~(+) variants of genes related to biofilm formation, virulence, catabolic activity, and nutrient uptake but marked decreases in transcription of genes related to various types of stress resistance. Supplying C~(+) variants with a functional rcsB restored resistance to heat shock and acid challenge in cells but blocked curli production, confirming that inactivation of RcsB in C~(+) variants was the basis of fitness segregation within the EcO157 population. This study provides an example of how genome instability of EcO157 promotes intrapopulation diversification, generating subpopulations carrying an array of distinct phenotypes that may confer the pathogen with survival advantages in diverse environments.
机译：Curli是肠杆菌科的粘附菌毛，并参与表面附着，细胞聚集和生物膜形成。我们以前曾报道过，大肠杆菌O157：H7（Cc（157））的产生卷曲的（C〜（+））变异体比相应的缺乏卷曲的（C〜（？））变异体对酸的敏感性更高。但是，这种差异与卷曲菌本身无关。在这里，我们调查了这种表型差异的潜在分子基础。我们从1993年美国汉堡相关暴发菌株中分离出C〜（+）变体的rcsB基因中发现了大的缺失。 rcsB编码RcsCDB两组分信号转导系统的响应调节剂，它负面地调节卷曲的生物发生，而正面地调节耐酸性。进一步比较应力适应性，发现C〜（+）变体对热休克也明显更敏感，但与C〜（？）变体相似，对渗透胁迫和氧化损伤具有抵抗力。转录组学分析发现在curli变体之间存在大量差异表达的基因，其特征在于C〜（+）变体中与生物膜形成，毒力，分解代谢活性和养分吸收有关的基因表达增强，但与各种类型的抗应力性。提供具有功能性rcsB的C〜（+）变体可恢复对细胞的热休克和酸攻击的抵抗力，但阻止卷曲生成，从而证实C〜（+）变体中RcsB的失活是EcO157群体中健身分离的基础。这项研究提供了一个示例，说明EcO157的基因组不稳定性如何促进种群内多样化，产生带有一系列不同表型的亚群体，这些表型可能使病原体在不同环境中具有生存优势。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号