The relevance of molecular epidemiological study between Extraintestinal pathological escherichis coli infection in the clinic and intestinal pathogenic escherichis coli / 重庆医科大学学报

ABSTRACT

sObjective:To investigate the epidemiological correlation of the Extraintestinal Pathogenic Escherichia coli(ExPEC)and the intestinal Pathogenic Escherichia coli.Methods:227 ExPEC strains isolated in the Department of Infectious Diseases of the First Affiliated Hospitial of Chongqing Medical University were studied to investigate their serotype by"OK"diagnostic serum.The virulence gene of the bacterium was analyzed by PCR.The homology of the intestinal Escherichia coli and ExPEC in some patients were analyzed by Pulsed field gel electrophoresis.Results:34 strains were selected in 227 ExPEC strains include 20(Enterotoxigenic escherichia coli,ETEC)strains,14(Enteropathogenic escherichia coli,EPEC)strains.The positive rate of virulence gene of ETEC were the heat labile enterotoxin gene (ltA)31.57%,heat stable enterotoxin gene(stI)47.36%and stI/ltA 21.05%.The positive rate of virulence gene of EPEC were the bundle-formingpilus gene(bfpA)66.66%,eeeA gene 60.0%and eaeA/bfpA 26.67%.Two cases of E.coli septicemia was found in patients with gut the same clone.Conclusion:Intestinal pathogenic E.coli serotype caused a relatively small proportion of the clinical ExPEC,and mainly ETEC and EPEC serotypes.ExPEC in patients with septemia,especially in serious ill patients,its intestinal translocation of E.coli may be the source of ExPEC.