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Xu, Yi Associate Professor


Our current research activities focus on understanding the pathogenic mechanism of Streptococcus gallolyticus subsp. gallolyticus (Sgg). Sgg is a gram-positive opportunistic pathogen that causes life-threatening bacteremia and infective endocarditis (IE). It is also strongly associated with colorectal cancer (CRC). My lab was the first to demonstrate that Sgg actively promotes the development of colon tumors, elevating a long-stranding clinical association to a functional causal role of Sgg in tumor development. Despite its medical importance, the pathogenic mechanism of Sgg remains poorly understood. Our recent studies have demonstrated that a type VII secretion system of Sgg plays a key role in pathogenesis. Currently we are interested in understanding the mechanism underlying following key steps in Sgg pathogenesis: 1) colonization of the intestinal epithelium, 2) modulation of intestinal homeostasis in normal and tumor-bearing colons, and 3) dissemination from the gastrointestinal tract to the circulatory system.

Keywords: bacterial pathogenesis, infectious diseases, virulence, colorectal cancer, microbiome, microbiota, type VII secretion system, gastrointestinal tract

Research Areas research areas

HR job title

  • Associate Professor