Verotoxin-producing Escherichia coli(VTEC) belonging to several different O serotypes, has been associated with watery or bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. One serotype (O157:H7) is now recognized as an important human pathogen of public health concern. Till now, little information was available on the global prevalence of VTEC of O157 and other serotypes in patients with diarrhea and HUS in Iraq.This book provides a unique data on the prevalence and characterization of VTEC obtained from patients with diarrhea.