The Characteristics Of Intestinal Pathogenic Escherichia Coli Causing The Extraintestinal Infection

Objective: The aim of our study is to analysis the characteristics of the intestinal Pathogenic Escherichia coli causing the extraintestinal infection.Methods: The total of 227 Extraintestinal Pathogenic E.coli (ExPEC)strains isolated in a teaching hospital were typed by the E.coli"OK"diagnosis serum. Then, the four virulence genes of E.coli attaching and effacing (eaeA), bundle-forming pilus (bfpA), the heat labile enterotoxin(lt ) ,heat stable enterotoxin(st) and phylogenetic grouping among 34 intestinal pathogenic Escherichia coli was investigated by PCR. The relationship between 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 ETEC strains and 14 EPEC strains, which account for 14.97% to all the strains. The 34 intestinal E.coli strains belong to groups A 30, B1 3,B2 1.The positive rate of virulence gene of ETEC were lt25%,st50%,st/lt20%. The positive rate of virulence gene of EPEC were bfpA 71.42%,eaeA 61.42%and eaeA/bfpA 28.5%.Two cases of E.coli septicemia was found in patients with gut the same clone, and the 2 patients had fever, diarrhea, blood WBC and neutrophil abnormalities increased.Conclusion: These current data that the serotypes of intestinal pathogenic E.coli can cause clinical Extraintestinal infection, but the proportion is relatively small, mainly ETEC and EPEC serotypes,and many base disease of Elderly hospitalized patients at high risk of this infection. ETEC infection in patients with sepsis, the intestinal translocation of E.coli may be the source of ETEC.