首页    期刊浏览 2024年11月24日 星期日
登录注册

文章基本信息

  • 标题:Unstable chromosome rearrangements in Staphylococcus aureus cause phenotype switching associated with persistent infections
  • 本地全文:下载
  • 作者:Ijeoma Lewechi Okoronkwo ; Emmanuel Chukwunonye Azuike ; Kamtoochukwu Maduneme Obi
  • 期刊名称:Proceedings of the National Academy of Sciences
  • 印刷版ISSN:0027-8424
  • 电子版ISSN:1091-6490
  • 出版年度:2019
  • 卷号:116
  • 期号:40
  • 页码:20135-20140
  • DOI:10.1073/pnas.1904861116
  • 出版社:The National Academy of Sciences of the United States of America
  • 摘要:Staphylococcus aureus small-colony variants (SCVs) are associated with unusually chronic and persistent infections despite active antibiotic treatment. The molecular basis for this clinically important phenomenon is poorly understood, hampered by the instability of the SCV phenotype. Here we investigated the genetic basis for an unstable S. aureus SCV that arose spontaneously while studying rifampicin resistance. This SCV showed no nucleotide differences across its genome compared with a normal-colony variant (NCV) revertant, yet the SCV presented the hallmarks of S. aureus linked to persistent infection: down-regulation of virulence genes and reduced hemolysis and neutrophil chemotaxis, while exhibiting increased survival in blood and ability to invade host cells. Further genome analysis revealed chromosome structural variation uniquely associated with the SCV. These variations included an asymmetric inversion across half of the S. aureus chromosome via recombination between type I restriction modification system (T1RMS) genes, and the activation of a conserved prophage harboring the immune evasion cluster (IEC). Phenotypic reversion to the wild-type–like NCV state correlated with reversal of the chromosomal inversion (CI) and with prophage stabilization. Further analysis of 29 complete S. aureus genomes showed strong signatures of recombination between hsdMS genes, suggesting that analogous CI has repeatedly occurred during S. aureus evolution. Using qPCR and long-read amplicon deep sequencing, we detected subpopulations with T1RMS rearrangements causing CIs and prophage activation across major S. aureus lineages. Here, we have discovered a previously unrecognized and widespread mechanism of reversible genomic instability in S. aureus associated with SCV generation and persistent infections.
  • 关键词:Staphylococcus aureus ; small-colony variant ; chromosomal rearrangement ; genome instability ; restriction modification system
国家哲学社会科学文献中心版权所有