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Agitation down-regulates immunoglobulin binding protein EibG expression in Shiga toxin-producing Escherichia coli (STEC).

Kuczius T, Zhang W, Merkel V, Mellmann A, Tarr PI, Karch H - PLoS ONE (2015)

Bottom Line: EibG proteins as well as corresponding mRNA were highly expressed under static growth conditions while shearing stress created by agitation during growth repressed protein synthesis.High and low EibG expression was reversible indicating a process with up- and down-regulation of the protein expression.Our findings indicate that shear stress represses EibG expression and might reduce bacterial attachments to cells and surfaces.

View Article: PubMed Central - PubMed

Affiliation: Institute for Hygiene, Westfälische Wilhelms-University and University Hospital Münster, Robert Koch-Strasse 41, 48149, Münster, Germany.

ABSTRACT
Shiga toxin (Stx)-producing Escherichia coli (STEC) carrying eibG synthesize Escherichia coli immunoglobulin binding protein (EibG). EibG nonspecifically binds to immunoglobulins and tends to aggregate in multimers but is poorly expressed in wild-type strains. To study synthesis of the proteins and their regulation in the pathogens, we identified natural growth conditions that increased EibG synthesis. EibG proteins as well as corresponding mRNA were highly expressed under static growth conditions while shearing stress created by agitation during growth repressed protein synthesis. Further regulation effects were driven by reduced oxygen tension, and pH up-regulated EibG expression, but to a lesser extent than growth conditions while decreased temperature down-regulated EibG. Bacteria with increased EibG expression during static growth conditions showed a distinct phenotype with chain formation and biofilm generation, which disappeared with motion. High and low EibG expression was reversible indicating a process with up- and down-regulation of the protein expression. Our findings indicate that shear stress represses EibG expression and might reduce bacterial attachments to cells and surfaces.

No MeSH data available.


Related in: MedlinePlus

Phenotypes of EibG-strains after agitation and static growth.Strain 2875/96 was inoculated for 20h at 37°C with and without shaking. Bacteria grown under agitated conditions grew homogenously and were turbid without biofilm formation (A). However, statically grown bacteria aggregated and deposited a biofilm (A). Aggregates and deposits were stained with crystal violet (B). Strain 659/97 was used as EibG negative control. Microscopically, shaken bacteria demonstrated single and non-aggregated cells whereas static grown bacteria formed coherent chains (C). The figures exemplify microscopic images of strain 2875/96 and 0520/99, magnified as indicated.
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pone.0119583.g004: Phenotypes of EibG-strains after agitation and static growth.Strain 2875/96 was inoculated for 20h at 37°C with and without shaking. Bacteria grown under agitated conditions grew homogenously and were turbid without biofilm formation (A). However, statically grown bacteria aggregated and deposited a biofilm (A). Aggregates and deposits were stained with crystal violet (B). Strain 659/97 was used as EibG negative control. Microscopically, shaken bacteria demonstrated single and non-aggregated cells whereas static grown bacteria formed coherent chains (C). The figures exemplify microscopic images of strain 2875/96 and 0520/99, magnified as indicated.

Mentions: Bacteria that express EibG demonstrate a chain-like adherence pattern to host epithelial cells [13, 30]. Agitated overnight bacterial cultures demonstrated homogenous growth with consistent turbidity (Fig. 4A), while statically grown bacteria formed clumps. A biofilm of the EibG, shown here for strain 2875/96, was detected as a deposit on the inoculation tube under static but not agitated growth (Fig. 4B) for EibG expressing wild-type strains. While cell chains formed under static growth, most bacterial cells remained solitary after agitated growth (Fig. 4C). Bacteria carrying cloned EibG-types produced biofilms as well; however the cell aggregation was less pronounced (data not shown). If any, very few chain formations were detectable. However, after static growth, increased numbers of chains were identified. These differential phenotypes were induced by static growth versus agitation, related to organisms with EibG of the α-type without (strain 2875/96) and with (strain 3671/97) EibC, and EibG of the γ-type (strain 0520/99) (Table 3). These data indicate a direct association between phenotype and EibG expression, with enhanced chain formation of EibG strains with growth conditions that augment EibG expression.


Agitation down-regulates immunoglobulin binding protein EibG expression in Shiga toxin-producing Escherichia coli (STEC).

Kuczius T, Zhang W, Merkel V, Mellmann A, Tarr PI, Karch H - PLoS ONE (2015)

Phenotypes of EibG-strains after agitation and static growth.Strain 2875/96 was inoculated for 20h at 37°C with and without shaking. Bacteria grown under agitated conditions grew homogenously and were turbid without biofilm formation (A). However, statically grown bacteria aggregated and deposited a biofilm (A). Aggregates and deposits were stained with crystal violet (B). Strain 659/97 was used as EibG negative control. Microscopically, shaken bacteria demonstrated single and non-aggregated cells whereas static grown bacteria formed coherent chains (C). The figures exemplify microscopic images of strain 2875/96 and 0520/99, magnified as indicated.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4352079&req=5

pone.0119583.g004: Phenotypes of EibG-strains after agitation and static growth.Strain 2875/96 was inoculated for 20h at 37°C with and without shaking. Bacteria grown under agitated conditions grew homogenously and were turbid without biofilm formation (A). However, statically grown bacteria aggregated and deposited a biofilm (A). Aggregates and deposits were stained with crystal violet (B). Strain 659/97 was used as EibG negative control. Microscopically, shaken bacteria demonstrated single and non-aggregated cells whereas static grown bacteria formed coherent chains (C). The figures exemplify microscopic images of strain 2875/96 and 0520/99, magnified as indicated.
Mentions: Bacteria that express EibG demonstrate a chain-like adherence pattern to host epithelial cells [13, 30]. Agitated overnight bacterial cultures demonstrated homogenous growth with consistent turbidity (Fig. 4A), while statically grown bacteria formed clumps. A biofilm of the EibG, shown here for strain 2875/96, was detected as a deposit on the inoculation tube under static but not agitated growth (Fig. 4B) for EibG expressing wild-type strains. While cell chains formed under static growth, most bacterial cells remained solitary after agitated growth (Fig. 4C). Bacteria carrying cloned EibG-types produced biofilms as well; however the cell aggregation was less pronounced (data not shown). If any, very few chain formations were detectable. However, after static growth, increased numbers of chains were identified. These differential phenotypes were induced by static growth versus agitation, related to organisms with EibG of the α-type without (strain 2875/96) and with (strain 3671/97) EibC, and EibG of the γ-type (strain 0520/99) (Table 3). These data indicate a direct association between phenotype and EibG expression, with enhanced chain formation of EibG strains with growth conditions that augment EibG expression.

Bottom Line: EibG proteins as well as corresponding mRNA were highly expressed under static growth conditions while shearing stress created by agitation during growth repressed protein synthesis.High and low EibG expression was reversible indicating a process with up- and down-regulation of the protein expression.Our findings indicate that shear stress represses EibG expression and might reduce bacterial attachments to cells and surfaces.

View Article: PubMed Central - PubMed

Affiliation: Institute for Hygiene, Westfälische Wilhelms-University and University Hospital Münster, Robert Koch-Strasse 41, 48149, Münster, Germany.

ABSTRACT
Shiga toxin (Stx)-producing Escherichia coli (STEC) carrying eibG synthesize Escherichia coli immunoglobulin binding protein (EibG). EibG nonspecifically binds to immunoglobulins and tends to aggregate in multimers but is poorly expressed in wild-type strains. To study synthesis of the proteins and their regulation in the pathogens, we identified natural growth conditions that increased EibG synthesis. EibG proteins as well as corresponding mRNA were highly expressed under static growth conditions while shearing stress created by agitation during growth repressed protein synthesis. Further regulation effects were driven by reduced oxygen tension, and pH up-regulated EibG expression, but to a lesser extent than growth conditions while decreased temperature down-regulated EibG. Bacteria with increased EibG expression during static growth conditions showed a distinct phenotype with chain formation and biofilm generation, which disappeared with motion. High and low EibG expression was reversible indicating a process with up- and down-regulation of the protein expression. Our findings indicate that shear stress represses EibG expression and might reduce bacterial attachments to cells and surfaces.

No MeSH data available.


Related in: MedlinePlus