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Medicine and Health Sciences Commons

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Uniformed Services University of the Health Sciences

1996

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Full-Text Articles in Medicine and Health Sciences

Activation Of Shiga-Like Toxins By Mouse And Human Intestinal Mucus Correlates With Virulence Of Enterohemorrhagic Escherichia Coli O91:H21 Isolates In Orally Infected, Streptomycin-Treated Mice, Angela R. Melton-Celsa, Stephen C. Darnell, Alison D. O'Brien Jan 1996

Activation Of Shiga-Like Toxins By Mouse And Human Intestinal Mucus Correlates With Virulence Of Enterohemorrhagic Escherichia Coli O91:H21 Isolates In Orally Infected, Streptomycin-Treated Mice, Angela R. Melton-Celsa, Stephen C. Darnell, Alison D. O'Brien

Uniformed Services University of the Health Sciences

The enterohemorrhagic Escherichia coli (EHEC) O91:H21 isolates B2F1 and H414-36/89 are virulent in an orally infected streptomycin-treated mouse model. Previous studies demonstrated that B2F1 and H414-36/89 grow to high levels in mucus isolated from the mouse small intestine and colon and that growth in smallintestinal mucus is related to virulence. We measured the levels of Shiga-like toxins (SLTs) SLT-IIvha and SLT-IIvhb produced by B2F1 after growth in Luria-Bertani (LB) broth supplemented with mouse intestinal mucus by assaying the cytotoxicity of culture supernatants on Vero cells. Culture supernatants from B2F1 grown in mouse intestinal mucus, but not EHEC strains that produce …


Truncated Enterohemorrhagic Escherichia Coli (Ehec) O157:H7 Intimin (Eaea) Fusion Proteins Promote Adherence Of Ehec Strains To Hep-2 Cells, Marian L. Mckee, Alison D. O'Brien Jan 1996

Truncated Enterohemorrhagic Escherichia Coli (Ehec) O157:H7 Intimin (Eaea) Fusion Proteins Promote Adherence Of Ehec Strains To Hep-2 Cells, Marian L. Mckee, Alison D. O'Brien

Uniformed Services University of the Health Sciences

Intimin, the product of the eaeA gene in enterohemorrhagic Escherichia coli O157:H7 (EHEC), is required for intimate adherence of these organisms to tissue culture cells and formation of the attaching and effacing lesion in the gnotobiotic pig. Because of the importance of intimin in the pathogenesis of EHEC O157:H7 infection in this animal model, we began a structure-function analysis of EaeA. For this purpose, we constructed amino-terminal fusions of the intimin protein with six histidine residues to form two independent fusions. The longer fusion, RIHisEae, contained 900 of the 935 predicted amino acids and included all but the extreme amino …