| Acid-stress-induced changes in enterohaemorrhagic Escherichia coli O157 : H7 virulence. | |
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MedLine Citation:
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PMID: 19497950 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Enterohaemorrhagic Escherichia coli (EHEC) O157 : H7 is naturally exposed to a wide variety of stresses including gastric acid shock, and yet little is known about how this stress influences virulence. This study investigated the impact of acid stress on several critical virulence properties including survival, host adhesion, Shiga toxin production, motility and induction of host-cell apoptosis. Several acid-stress protocols with relevance for gastric passage as well as external environmental exposure were included. Acute acid stress at pH 3 preceded by acid adaptation at pH 5 significantly enhanced the adhesion of surviving organisms to epithelial cells and bacterial induction of host-cell apoptosis. Motility was also significantly increased after acute acid stress. Interestingly, neither secreted nor periplasmic levels of Shiga toxin were affected by acid shock. Pretreatment of bacteria with erythromycin eliminated the acid-induced adhesion enhancement, suggesting that de novo protein synthesis was required for the enhanced adhesion of acid-shocked organisms. DNA microarray was used to analyse the transcriptome of an EHEC O157 : H7 strain exposed to three different acid-stress treatments. Expression profiles of acid-stressed EHEC revealed significant changes in virulence factors associated with adhesion, motility and type III secretion. These results document profound changes in the virulence properties of EHEC O157 : H7 after acid stress, provide a comprehensive genetic analysis to substantiate these changes and suggest strategies that this pathogen may use during gastric passage and colonization in the human gastrointestinal tract. |
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Authors:
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B House; J V Kus; N Prayitno; R Mair; L Que; F Chingcuanco; V Gannon; D G Cvitkovitch; D Barnett Foster |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2009-06-04 |
Journal Detail:
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Title: Microbiology (Reading, England) Volume: 155 ISSN: 1350-0872 ISO Abbreviation: Microbiology (Reading, Engl.) Publication Date: 2009 Sep |
Date Detail:
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Created Date: 2009-09-01 Completed Date: 2009-12-09 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9430468 Medline TA: Microbiology Country: England |
Other Details:
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Languages: eng Pagination: 2907-18 Citation Subset: IM |
Affiliation:
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Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada. |
| Data Bank Information | |
Bank Name/Acc. No.:
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GEO/GSE14069 |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Apoptosis Bacterial Adhesion / drug effects Cell Line Epithelial Cells / microbiology, physiology Erythromycin / pharmacology Escherichia coli Infections / metabolism, microbiology* Escherichia coli O157 / drug effects, pathogenicity*, physiology Gene Expression Profiling Host-Pathogen Interactions / drug effects Humans Hydrogen-Ion Concentration Protein Synthesis Inhibitors / pharmacology Shiga Toxins / biosynthesis Stress, Physiological* Virulence Virulence Factors / biosynthesis, genetics |
| Chemical | |
Reg. No./Substance:
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0/Protein Synthesis Inhibitors; 0/Shiga Toxins; 0/Virulence Factors; 114-07-8/Erythromycin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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