الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Enterotoxigenic Escherichia coli strains (ETEC) are a major cause of diarrheal disease in the developing world and is also an important cause of diarrhea in adult travelers to these regions. On an annual basis, ETEC strains have been estimated to cause 400 million episodes of diarrhea in children under age 5, resulting in 700,000 deaths. As a cause of traveler’s diarrhea, it has substantial impacts in terms of both morbidity and economic consequences.
These organisms cause diarrhea by producing either a high-molecular-weight heat-labile enterotoxin or a low-molecular-weight heat-stable enterotoxin. Although there is no histological evidence of intestinal damage or evidence of injury to non-erythrocytic cells in vitro assays by ETEC, enterotoxins produces net secretion in intestinal segments.
Considerable effort has been devoted to the development of a safe and broadly protective vaccine for ETEC. While there is not currently a vaccine for ETEC that can offer sustained, broad-based protection, multiple lines of evidence suggest that an ETEC vaccine is feasible. Prior to the advent of whole-genome sequencing projects, much of the effort expended toward development of an ETEC vaccine necessarily focused intensively on a limited subset of antigens, namely, the fimbrial colonization factors and toxins. The availability of DNA sequence from multiple ETEC strains provides new avenues for antigen discovery, including immunoproteomics approaches
This study depended on molecular characterization of the gene eaeH of ETEC that recently has been described as adhesin. The sequence corresponding to the eaeH gene was confirmed as conservative gene in ETEC strains. This study reported the cloning of eaeH gene, expression and purification of the recombinant EaeH protein. In vitro study of the recombinant protein demonstrated that:
• The protein plays an important role in the adherence of the ETEC to the host cells.
• The use of polyclonal antibody raised against EaeH protein was sufficient to block the adherence of ETEC to epithelial cells.
• The gene functions in the way that favors toxin delivery.
• The protein is a part of the outer membrane proteins.
• The protein expressed during the course of ETEC infection and has an immune response.
Together, these results suggest that targeting EaeH in vaccines could present a novel strategy to prevent diarrheal illness.