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Oxidative Stress in Shiga Toxin Production by Enterohemorrhagic Escherichia coli

Licznerska, Katarzyna and Nejman-Faleńczyk, Bożena and Bloch, Sylwia and Dydecka, Aleksandra and Topka, Gracja and Gąsior, Tomasz and Węgrzyn, Alicja and Węgrzyn, Grzegorz (2016) Oxidative Stress in Shiga Toxin Production by Enterohemorrhagic Escherichia coli. Oxidative Medicine and Cellular Longevity, 2016 (357836). ISSN 1942-0900

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Virulence of enterohemorrhagic Escherichia coli (EHEC) strains depends on production of Shiga toxins. These toxins are encoded in genomes of lambdoid bacteriophages (Shiga toxin-converting phages), present in EHEC cells as prophages. The genes coding for Shiga toxins are silent in lysogenic bacteria, and prophage induction is necessary for their efficient expression and toxin production. Under laboratory conditions, treatment withUV light or antibiotics interfering withDNA replication are commonly used to induce lambdoid prophages. Since such conditions are unlikely to occur in human intestine, various research groups searched for other factors or agents that might induce Shiga toxin-converting prophages. Among other conditions, it was reported that treatment with H2O2 caused induction of these prophages, though with efficiency significantly lower relative to UV-irradiation or mitomycin C treatment. A molecular mechanism of this phenomenon has been proposed. It appears that the oxidative stress represents natural conditions provoking induction of Shiga toxin-converting prophages as a consequence of H2O2 excretion by either neutrophils in infected humans or protist predators outside human body. Finally, the recently proposed biological role of Shiga toxin production is described in this paper, and the “bacterial altruism” and “Trojan Horse” hypotheses, which are connected to the oxidative stress, are discussed.

Item Type:Article
Subjects:Q Science > QH Natural history > QH301 Biology
Q Science > QH Natural history > QH426 Genetics
Q Science > QR Microbiology
Q Science > QR Microbiology > QR355 Virology
Divisions:Laboratory of Molecular Biology (in Gdansk)
ID Code:1307
Deposited By: PhD Piotr Golec
Deposited On:18 Jan 2017 12:50
Last Modified:18 Jan 2017 12:50

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