1Department of Microbiology, Razi Vaccine and Serum Research Institute, Karaj, Iran
2Department of Bacteriology, School of Medicine, Tarbiat Modarres University, Tehran, Iran
3Department of Anatomical Sciences, Faculty of Medicine, Shahid Beheshty University of Medical Sciences, Tehran, Iran
Escherichia coli O157:H7 is found in cattle farms and can live in the intestine of healthy cattle. Most cases of human illnesses including nonbloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome can be traced, either directly or indirectly, to cattle. One strategy for reducing the risk of Enterohemorrhagic Escherichia coli (EHEC) infections in human is to reduce the prevalence of infection in cattle. Antiserum against whole cell of isolated E. coli O157:H7 from cattle showed inhibition of adherence of this strain to HEP-2 cells and intestine of model mice. The ability of this antiserum in blocking the attachment of bacteria to HEP-2 cells in 1:1280 titer and to intestine tissue of mice in 1:640 titer are significant. Histology of intestine tissue confirms our results. The difference between in vivo and in vitro titrations for blocking the attachment depends on these two different conditions.