1. Bacteriophage Transcription Factor Cro Regulates Virulence Gene Expression in Enterohemorrhagic Escherichia coli.
- Author
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Hernandez-Doria JD and Sperandio V
- Subjects
- Animals, Chromosomes, Bacterial drug effects, Citrobacter rodentium pathogenicity, Coliphages genetics, Disease Models, Animal, Enterobacteriaceae Infections metabolism, Enterobacteriaceae Infections pathology, Enterohemorrhagic Escherichia coli pathogenicity, Enterohemorrhagic Escherichia coli virology, Escherichia coli genetics, Escherichia coli Infections microbiology, Escherichia coli Proteins genetics, Genes, Bacterial drug effects, HeLa Cells, Humans, Lipids, Lysogeny, Mice, Mice, Inbred C3H, Repressor Proteins genetics, Shiga Toxin genetics, Transcription Factors, Type III Secretion Systems drug effects, Type III Secretion Systems genetics, Type III Secretion Systems metabolism, Viral Plaque Assay, Viral Regulatory and Accessory Proteins genetics, Virulence drug effects, Virulence genetics, Coliphages metabolism, Enterohemorrhagic Escherichia coli drug effects, Enterohemorrhagic Escherichia coli genetics, Gene Expression Regulation, Bacterial drug effects, Repressor Proteins pharmacology, Viral Regulatory and Accessory Proteins pharmacology, Virulence Factors genetics
- Abstract
Bacteriophage-encoded genetic elements control bacterial biological functions. Enterohemorrhagic Escherichia coli (EHEC) strains harbor lambda-phages encoding the Shiga-toxin (Stx), which is expressed during the phage lytic cycle and associated with exacerbated disease. Phages also reside dormant within bacterial chromosomes through their lysogenic cycle, but how this impacts EHEC virulence remains unknown. We find that during lysogeny the phage transcription factor Cro activates the EHEC type III secretion system (T3SS). EHEC lambdoid phages are lysogenic under anaerobic conditions when Cro binds to and activates the promoters of T3SS genes. Interestingly, the Cro sequence varies among phages carried by different EHEC outbreak strains, and these changes affect Cro-dependent T3SS regulation. Additionally, infecting mice with the related pathogen C. rodentium harboring the bacteriophage cro from EHEC results in greater T3SS gene expression and enhanced virulence. Collectively, these findings reveal the role of phages in impacting EHEC virulence and their potential to affect outbreak strains., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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