Abstract:To understand the specific genes and virulent genes profiles of the O157∶H7 strains isolated from China and the distribution in different host animal.PCR was used to identify the specific rfbEO157,fliCH7 genes and virulent genes of stx1,stx2,eaeA and hlyA.The specific rfbEO157,fliCH7 genes were found in all of the 345 strains of E.coli O157∶H7 isolated from 1992 to 2006 in China.99.4% and 99.1% of the tested strains were positive for eaeA and hlyA respectively.91.9 % strains carried stx2 gene.Only 13.3% strains carried stx1 gene,but 13.0% strains carried both stx1 and stx2.The positive rate of stx2 was much higher than that of stx1 in strains isolated from patients and animals.eaeA+hlyA+stx2 was the dominant virulent genotype.The Escherichia coli O157∶H7 strain that carried virulent genes is widely present in goat,cattle and other animal hosts.The results demonstrates that stx2 is the dominant virulent gene of Shiga toxin-producing E.coli O157∶H7 isolates from patients and animals.
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