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bioRxiv · 10.1101/2022.07.30.502126

Enhanced production of natural shiga toxin by overexpressing A subunit of Stx2e in Stx2e-producing Escherichia coli isolated in South Korea

Hur, J.·Seo, B. J.·Yu, J. H.·Kim, S. C.·Yu, Y. J.·Park, B. Y.·Park, J. H.·Kim, W. I.
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Abstract

This study explored the optimal culture conditions for maximizing shiga toxin production in Stx2e-producing Escherichia coli (STEC) 150229, isolated from porcine edema disease (ED), with the goal of preparing a Stx2e toxoid vaccine candidate. High cytotoxicity was observed for this strain [tissue culture cytotoxic dose 50% (104 TCCD50/100 {micro}l)] from 48 h after incubation. Stx2e was overexpressed by transforming pStx2e A into STEC 150229, resulting in the production of recombinant Stx2e A/B complex combined with intrinsic Stx2e B. The enhanced production of Stx2e was evaluated based on the level of cytotoxicity against Vero cells. The highest cytotoxicity (105 TCCD50/100 {micro}l) was observed with the samples of recombinant Stx2e A/B complex eluted with 500 mM imidazole at 48 h of incubation. In conclusion, the recombinant Stx2e A protein forms an active protein complex with the intrinsic Stx2e B component from STEC 150229, producing high levels of shiga toxin.

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Hur, J., Seo, B. J., Yu, J. H., Kim, S. C., Yu, Y. J., Park, B. Y., Park, J. H., Kim, W. I.. 2022-07-30. Enhanced production of natural shiga toxin by overexpressing A subunit of Stx2e in Stx2e-producing Escherichia coli isolated in South Korea. https://doi.org/10.1101/2022.07.30.502126

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