肠道致病菌感染位点识别机制

Molecular mechanisms of infection site recognition by enteric pathogens

肠道是病原菌定殖和感染的主要人体器官.肠道感染每年在世界范围内可造成150~250万人死亡,居所有疾病的第三位.不同的肠道致病菌选择不同的肠道部位侵染、定殖,其中小肠和大肠是病原菌在肠道内定殖和感染的最主要位点.在致病过程中,肠道致病菌通过感受一系列环境信号(生物素、核酸、氧、短链脂肪酸、胆盐等)来精确识别其感染位点,启动致病基因表达,快速吸附或入侵肠上皮细胞,进而导致疾病发生.本文简要综述两种最重要的致病菌(大肠致病菌——肠出血性大肠杆菌,小肠致病菌——沙门氏菌)的感染位点识别机制.

In humans,the bacterial pathogen infections occur primarily in the intestine.Every year,intestinal diseases cause 1.5–2.5 million deaths,holding the third highest mortality rate among all diseases.Different enteric pathogens recognize different intestinal sites for colonization and infection,among which human small intestine and large intestine are the main infection sites.During the pathogenic process,enteric pathogens sense a series of intestinal signals to accurately identify their infection sites,and adhere to or invade the intestinal epithelium through activating the expression of virulence genes.Here,we review the molecular mechanisms by which two representative enteric pathogens(large intestinal pathogen enterohemorrhagic Escherichia coli and small intestinal pathogen Salmonella typhimurium)recognize their infection sites.