Abstract: Objective To survey the infection situation of diagrrheagenic Escherichia coli(DEC) in intestinal infectious disease, and to analyze the molecular epidemiology characteristics of DEC. Methods The etiological survey was performed continuously through enrolling the cases with gastric and intestinal infectious diseases. The primer probe segements of 10 pairs of virulent genes were determined. The epidemiology distribution characteristics of DEC were analyzed. Results The positive rates of DEC were 9%[including enteroinvasive Escherichia coli(EIEC), enteropathogenic Escherichia coli(EPEC), enterotoxigenic Escherichia coli(ETEC) and enterohemorrhagic Escherichia coli(EHEC)],12%[including enteroaggregative Escherichia coli(EAEC)],17%[including EAEC and diffusively adherent Escherichia coli(DAEC)] and 23%(including EAEC and stable toxin positive). EAEC and DAEC had aging change, and ETEC and DAEC had seasonal fluctuation. DEC was independent of sex . Conclusions The DEC has aging change and seasonal fluctuation. Strengthening the etiological survey of DEC is the foundation of investigating the DEC molecular epidemiology.

Key words: Diagrrheagenic Escherichia coli, Etiological survey, Molecular epidemiology