Regulation of waaH by PhoB during P i Starvation Promotes Biofilm Formation by Escherichia coli O157:H7
| Autor: | Samuel M. Chekabab, Philippe Vogeleer, Antony T. Vincent, Martine Caroff, Alexey Novikov, Steve J. Charette, Josée Harel, Mario Jacques, Francis Beaudry |
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| Rok vydání: | 2019 |
| Předmět: |
Mutant
Escherichia coli O157 medicine.disease_cause Microbiology Bacterial Adhesion Phosphates 03 medical and health sciences Glycosyltransferase Extracellular medicine Molecular Biology Escherichia coli Gene 030304 developmental biology 2. Zero hunger 0303 health sciences biology 030306 microbiology Escherichia coli Proteins Biofilm Transporter Gene Expression Regulation Bacterial biochemical phenomena metabolism and nutrition Up-Regulation Cell biology Regulon Hexosyltransferases Biofilms Mutation biology.protein Meeting Presentation Transcription Factors |
| Zdroj: | Journal of Bacteriology. 201 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.00093-19 |
| Popis: | In open environments such as water, enterohemorrhagic Escherichia coli O157:H7 responds to inorganic phosphate (P(i)) starvation by inducing the Pho regulon controlled by PhoB. This activates the phosphate-specific transport (Pst) system that contains a high-affinity P(i) transporter. In the Δpst mutant, PhoB is constitutively activated and regulates the expression of genes in the Pho regulon. Here, we show that P(i) starvation and deletion of the pst system enhance E. coli O157:H7 biofilm formation. Among differentially expressed genes of EDL933 grown under P(i) starvation conditions and in the Δpst mutant, we have found that a member of the PhoB regulon, waaH, predicted to encode a glycosyltransferase, was highly expressed. Interestingly, WaaH contributed to biofilm formation of E. coli O157:H7 during both P(i) starvation and in the Δpst mutant. In the Δpst mutant, the presence of waaH was associated with lipopolysaccharide (LPS) R3 core type modifications, whereas in E. coli O157:H7, waaH overexpression had no effect on LPS structure during P(i) starvation. Therefore, waaH participates in E. coli O157:H7 biofilm formation during P(i) starvation, but its biochemical role remains to be clarified. This study highlights the importance of the P(i) starvation stress response to biofilm formation, which may contribute to the persistence of E. coli O157:H7 in the environment. IMPORTANCE Enterohemorrhagic Escherichia coli O157:H7 is a human pathogen that causes bloody diarrhea that can result in renal failure. Outside of mammalian hosts, E. coli O157:H7 survives for extended periods of time in nutrient-poor environments, likely as part of biofilms. In E. coli K-12, the levels of free extracellular P(i) affect biofilm formation; however, it was unknown whether P(i) influences biofilm formation by E. coli O157:H7. Our results show that upon P(i) starvation, PhoB activates waaH expression, which favors biofilm formation by E. coli O157:H7. These findings suggest that WaaH is a target for controlling biofilm formation. Altogether, our work demonstrates how adaptation to P(i) starvation allows E. coli O157:H7 to occupy different ecological niches. |
| Databáze: | OpenAIRE |
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