The identification of novel vaccine antigens and their potential role in preventing VTEC infections in children

VTEC are a group of strains of E. coli, which cause severe bloody diarrhoea. VTEC infections can lead to the development of haemolytic uremic syndrome (HUS), which is the main cause of kidney failure among children. HUS can cause other life-long complications including seizures, bowel perforation and blindness. Ireland currently has the highest incidence of VTEC infections compared to any other European country. There are no vaccines available to protect children and immunocompromised adults against VTEC infections. Due to the risk of patients experiencing severe symptoms and complications, there is an urgent need for a vaccine against this infection. Bacterial proteins involved in host cell attachment have previously been shown to be efficacious prophylactic vaccine antigens for other infections. We have shown that an O157 strain, NCTC12900 has 1.3-fold higher binding to HT29 cells than the commensal strain, HS (P=0.0162). We have used a proteomic approach to identify the bacterial proteins involved in attachment to two human gastrointestinal epithelial cell lines, HT29 and Caco-2. We have identified seven host cell attachment proteins in VTEC, strain NCTC12900, that are not found in commensal strain, HS. These antigens will be examined for their ability to protect mice from VTEC challenge.