Bile Salts Differentially Enhance Resistance of Enterohemorrhagic Escherichia coli O157:H7 to Host Defense Peptides
| Autor: | Aju-Sue Francis, Debora Barnett Foster, Crystal Gadishaw-Lue, Alyssa Banaag, Sarah Birstonas |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Immunology
Virulence medicine.disease_cause Microbiology Bile Acids and Salts Lipid A 03 medical and health sciences medicine Humans Pathogen Escherichia coli Defensin Escherichia coli Infections Disease Resistance 030304 developmental biology 0303 health sciences biology 030306 microbiology Human gastrointestinal tract biology.organism_classification Molecular Pathogenesis Small intestine 3. Good health Galleria mellonella Infectious Diseases medicine.anatomical_structure Enterohemorrhagic Escherichia coli Parasitology Antimicrobial Cationic Peptides |
| Zdroj: | Infect Immun |
| ISSN: | 1098-5522 0019-9567 |
| DOI: | 10.1128/iai.00719-20 |
| Popis: | During passage through the human gastrointestinal tract, enterohemorrhagic Escherichia coli (EHEC) is exposed to membrane-damaging bile in the small intestine. We previously reported that EHEC treatment with a physiological bile salt mixture upregulates basRS, encoding a two-component system, and arnBCADTEF, encoding the aminoarabinose lipid A modification pathway (J. V. Kus, A. Gebremedhin, V. Dang, S. L. Tran, A. Serbanescu, and D. Barnett Foster, J Bacteriol 193: 4509–4515, 2011, https://doi.org/10.1128/JB.00200-11). The present study examined the effect of bile salt mix (BSM) treatment on EHEC resistance to three human gastrointestinal defense peptides—HD-5, HNP-1, and LL-37—as well as the role of basRS and arnT in the respective responses. After BSM treatment, EHEC resistance to HD-5 and HNP-1 was significantly increased in a BSM-, defensin dose-dependent manner. The resistance phenotype was dependent on both basRS and arnT. However, the BSM treatment did not alter EHEC resistance to LL-37, even when the ompT gene, encoding an LL-37 cleavage protease, was disrupted. Interestingly, enteropathogenic E. coli, a related pathogen that infects the small intestine, showed a similar BSM-induced resistance phenotype. Using a model of EHEC infection in Galleria mellonella, we found significantly lower survival rates in wax moth larvae infected with BSM-treated wild-type EHEC than in those infected with a BSM-treated basS mutant, suggesting that treatment with a physiological BSM enhances virulence through a basS-mediated pathway. The results of this investigation provide persuasive evidence that bile salts typically encountered during transit through the small intestine can serve as an environmental cue for EHEC, enhancing resistance to several key host defense peptides. |
| Databáze: | OpenAIRE |
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