Escherichia coli (E. coli) bacteria cause numerous diseases including meningitis, urinary tract infections and diarrhea. Worldwide, enteropathogenic E. coli (EPEC) is one of the leading causes of diarrhea in children and is an endemic health threat in the developing world, causing the death of several hundred thousand people each year. Isolated outbreaks of enterohaemorrhagic E. coli (EHEC) also occur in developed countries, often transmitted in contaminated hamburgers and water supplies, and can cause diarrhea and fatal kidney disease. After binding to the cells that line the intestine, E. coli injects several proteins that lead to diarrhea and disease. Dr. Philip Hardwidge aims to identify these proteins and determine their structure and function. He is also examining how intestinal cells respond to E. coli at the level of gene expression, using an advanced technique to analyze several thousand genes at a time. This research could guide the design of future vaccines and antibiotics to prevent and treat E. coli.