Ruminants are a major reservoir of enterohaemorrhagic Escherichia coli (EHEC), which cause acute gastroenteritis in humans with potentially life-threatening sequelae. The mechanisms underlying EHEC persistence in ruminant hosts are poorly understood. EHEC produce several cytotoxins that inhibit the proliferation of bovine lymphocytes in vitro and influence EHEC persistence in calves, suggesting...

Molly M. Leeper Trends in Toxin Profiles of Human Shiga Toxin-Producing Escherchia coli (STEC) O157 Strains, United States, 1996-2008 (Under the direction of Dr. Karen Gieseker, faculty member) Shiga toxin-producing E. coli (STEC) cause diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). All STEC produce one or both of two Shiga toxins, Stx1 and Stx2. STEC strains that produce S...

Escherichia coli O157:H7 causes life-threatening outbreaks of diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome in humans and significant economic loss in agriculture and could be a potential agent of bioterrorism. Although the prevalence of E. coli O157:H7 in cattle and other species with which humans have frequent contact is high, human infections are relatively uncommon, despite a...

Cattle are the main reservoirs for Shiga-toxin-producing Escherichia coli (STEC), the only known zoonotic intestinal E. coli pathotype. However, there are other intestinal pathotypes that can cause disease in humans, whose presence has been seldom investigated. Thus, our aim was to identify the effects of anthropic pressure and of wild and domestic ungulate abundance on the distribution and div...

Shiga toxin type 1 (Stx1) belongs to the Shiga family of bipartite AB toxins that inactivate eukaryotic 60S ribosomes. The A subunit of Stxs are N-glycosidases that share structural and functional features in their catalytic center and in an internal hydrophobic region that shows strong transmembrane propensity. Both features are conserved in ricin and other ribosomal inactivating proteins. Dur...

AIM Wild birds are considered silent vectors of some zoonotic water and food borne pathogens of public health significance. Owing to the importance of Shiga toxin producing Escherichia coli (STEC) as the most pathogenic among the emerging diarrheagenic E. coli groups that can infect man; the present study was designed to detect the occurrence of STEC among wild birds in Egypt. MATERIALS AND M...

Bacteriophages are major genetic factors promoting horizontal gene transfer (HGT) between bacteria. Their roles in dynamic bacterial genome evolution have been increasingly highlighted by the fact that many sequenced bacterial genomes contain multiple prophages carrying a wide range of genes. Enterohemorrhagic Escherichia coli O157 is the most striking case. A sequenced strain (O157 Sakai) poss...

background and objective: diarrheal disease is still a major health problem, especially in developing countries, where it is considered as one of the leading causes of morbidity and mortality especially in children. studies showed that diarrheagenic e. coli (dec) such as stes and epec strains are among the most prevalent causative agents in acute diarrhea, particularly in children. aim of the p...

background and objectives: shiga toxin-producing escherichia coli ( stec) have emerged as human pathogens and contamination of foods of animal origin has been a major public health concern. the aim of the present study was to determine the dissemination of stec in healthy and diarrheic calves in urmia region which is located in west azerbaijan province, iran. materials and methods: in the curre...