Grant: CAG/CIHR Fellowship for Research in Gastroenterology/Nutrition

Enteropathogenic Escherichia coli (EPEC) is a major cause of bacterial-mediated infantile diarrhea and poses a serious health threat to young children in developing countries. In industrialized countries, enterohemorrhagic E. coli (EHEC) causes a more severe diarrhea and can progress to a fatal kidney disease. The route of bacterial infections often occurs by the ingestion or inhalation of the bacteria. Once inside the host, the bacteria replicate and seek to exit the host to spread to a new susceptible host. This dissemination of bacteria is called transmission and can occur through various means such as insect bites, fecal shedding or, aerosols created by sneezing or coughing. Both EPEC and EHEC are transmitted through the fecal-oral route, with an infectious dose of EHEC being less than 100 cells. Sources of contamination can range from direct contact with symptomatic or asymptomatic carriers, food, drinking water or petting zoos and farms. To put this into perspective, the 2000 EHEC outbreak in Walkerton, Ontario was caused by contaminated drinking water and resulted in 2300 cases and 7 deaths. This exemplifies the serious public health concern posed by these pathogens. Little is known about strategies that pathogens use to transmit from host to host. My research aims to identify these strategies and determine how they contribute to the spread of disease. This project will lay the groundwork for the largely understudied area of bacterial transmission. The identification of strategies involved in transmission will provide insights and increase our general understanding of transmission. This may also lead to targets for new therapeutic treatments that may help prevent the spread of disease.