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Shiga toxin production and translocation during microaerobic human colonic infection with Shiga toxin-producing E. coli O157:H7 and O104:H4.

Tran SL, Billoud L, Lewis SB, Phillips AD, Schüller S - Cell. Microbiol. (2014)

Bottom Line: Haemolytic uraemic syndrome caused by Shiga toxin-producing E. coli (STEC) is dependent on release of Shiga toxins (Stxs) during intestinal infection and subsequent absorption into the bloodstream.An understanding of Stx-related events in the human gut is limited due to lack of suitable experimental models.Whereas microaerobiosis significantly reduced bacterial growth as well as Stx production and release into the medium, Stx translocation across the epithelial monolayer was enhanced under MA versus aerobic conditions.

View Article: PubMed Central - PubMed

Affiliation: Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK; Gut Health and Food Safety Programme, Institute of Food Research, Norwich Research Park, Norwich, UK.

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Microaerobiosis reduces growth, Stx production and release in STEC EDL933, Walla-1 and H1121. Polarized T84 cells were infected for 5 h under AE (■) or MA (□) conditions.A. Bacterial growth was assessed by OD600. Data are shown as means ± SEM from five independent experiments performed in duplicate. **P < 0.01, ***P < 0.001 versus AE conditions; $$P < 0.01 versus EDL933 AE.B. Stx2 levels in apical supernatants were quantified by ELISA. Data are shown as means ± SEM from four independent experiments performed in duplicate. *P < 0.05, **P < 0.01, ***P < 0.001 versus AE; $$$P < 0.001 versus EDL933 AE; &P < 0.05, &&&P < 0.001 versus EDL933 MA.C. Stx1 production in bacterial lysates of EDL933 (E), Walla-1 (W) and H1121(H) under AE (A) and MA (M) conditions was determined by Western blotting. Amounts of loaded bacterial protein were assessed by GroEL expression. The marker lane (M) indicates 58 kDa for GroEL and 30 kDa for Stx1. Shown are representative images from three independent experiments.
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fig06: Microaerobiosis reduces growth, Stx production and release in STEC EDL933, Walla-1 and H1121. Polarized T84 cells were infected for 5 h under AE (■) or MA (□) conditions.A. Bacterial growth was assessed by OD600. Data are shown as means ± SEM from five independent experiments performed in duplicate. **P < 0.01, ***P < 0.001 versus AE conditions; $$P < 0.01 versus EDL933 AE.B. Stx2 levels in apical supernatants were quantified by ELISA. Data are shown as means ± SEM from four independent experiments performed in duplicate. *P < 0.05, **P < 0.01, ***P < 0.001 versus AE; $$$P < 0.001 versus EDL933 AE; &P < 0.05, &&&P < 0.001 versus EDL933 MA.C. Stx1 production in bacterial lysates of EDL933 (E), Walla-1 (W) and H1121(H) under AE (A) and MA (M) conditions was determined by Western blotting. Amounts of loaded bacterial protein were assessed by GroEL expression. The marker lane (M) indicates 58 kDa for GroEL and 30 kDa for Stx1. Shown are representative images from three independent experiments.

Mentions: Experiments to study the effect of oxygen on bacterial growth and Stx2 release were extended to O157:H7 strain Walla-1 and O104:H4 strain H1121. Both strains produce the same Stx2 subtype as EDL933 (Stx2a) but do not produce Stx1. Similar to EDL933, both strains showed significantly reduced growth and Stx2 supernatant levels under MA versus AE conditions (Fig. 6A and B). In addition, aerobic growth of H1121 was significantly lower compared with EDL933 (Fig. 6A) and Stx2 release by Walla-1 and H1121 was significantly reduced compared with EDL933 under AE and MA conditions (Fig. 6B).


Shiga toxin production and translocation during microaerobic human colonic infection with Shiga toxin-producing E. coli O157:H7 and O104:H4.

Tran SL, Billoud L, Lewis SB, Phillips AD, Schüller S - Cell. Microbiol. (2014)

Microaerobiosis reduces growth, Stx production and release in STEC EDL933, Walla-1 and H1121. Polarized T84 cells were infected for 5 h under AE (■) or MA (□) conditions.A. Bacterial growth was assessed by OD600. Data are shown as means ± SEM from five independent experiments performed in duplicate. **P < 0.01, ***P < 0.001 versus AE conditions; $$P < 0.01 versus EDL933 AE.B. Stx2 levels in apical supernatants were quantified by ELISA. Data are shown as means ± SEM from four independent experiments performed in duplicate. *P < 0.05, **P < 0.01, ***P < 0.001 versus AE; $$$P < 0.001 versus EDL933 AE; &P < 0.05, &&&P < 0.001 versus EDL933 MA.C. Stx1 production in bacterial lysates of EDL933 (E), Walla-1 (W) and H1121(H) under AE (A) and MA (M) conditions was determined by Western blotting. Amounts of loaded bacterial protein were assessed by GroEL expression. The marker lane (M) indicates 58 kDa for GroEL and 30 kDa for Stx1. Shown are representative images from three independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig06: Microaerobiosis reduces growth, Stx production and release in STEC EDL933, Walla-1 and H1121. Polarized T84 cells were infected for 5 h under AE (■) or MA (□) conditions.A. Bacterial growth was assessed by OD600. Data are shown as means ± SEM from five independent experiments performed in duplicate. **P < 0.01, ***P < 0.001 versus AE conditions; $$P < 0.01 versus EDL933 AE.B. Stx2 levels in apical supernatants were quantified by ELISA. Data are shown as means ± SEM from four independent experiments performed in duplicate. *P < 0.05, **P < 0.01, ***P < 0.001 versus AE; $$$P < 0.001 versus EDL933 AE; &P < 0.05, &&&P < 0.001 versus EDL933 MA.C. Stx1 production in bacterial lysates of EDL933 (E), Walla-1 (W) and H1121(H) under AE (A) and MA (M) conditions was determined by Western blotting. Amounts of loaded bacterial protein were assessed by GroEL expression. The marker lane (M) indicates 58 kDa for GroEL and 30 kDa for Stx1. Shown are representative images from three independent experiments.
Mentions: Experiments to study the effect of oxygen on bacterial growth and Stx2 release were extended to O157:H7 strain Walla-1 and O104:H4 strain H1121. Both strains produce the same Stx2 subtype as EDL933 (Stx2a) but do not produce Stx1. Similar to EDL933, both strains showed significantly reduced growth and Stx2 supernatant levels under MA versus AE conditions (Fig. 6A and B). In addition, aerobic growth of H1121 was significantly lower compared with EDL933 (Fig. 6A) and Stx2 release by Walla-1 and H1121 was significantly reduced compared with EDL933 under AE and MA conditions (Fig. 6B).

Bottom Line: Haemolytic uraemic syndrome caused by Shiga toxin-producing E. coli (STEC) is dependent on release of Shiga toxins (Stxs) during intestinal infection and subsequent absorption into the bloodstream.An understanding of Stx-related events in the human gut is limited due to lack of suitable experimental models.Whereas microaerobiosis significantly reduced bacterial growth as well as Stx production and release into the medium, Stx translocation across the epithelial monolayer was enhanced under MA versus aerobic conditions.

View Article: PubMed Central - PubMed

Affiliation: Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, UK; Gut Health and Food Safety Programme, Institute of Food Research, Norwich Research Park, Norwich, UK.

Show MeSH
Related in: MedlinePlus