Distribution of espP gene in Escherichia coli O157 ∶ H7 isolates

Objective To determine the distribution of espP gene in Shiga toxin-producing Escherichia coli O157 strains isolated in several regions of China. Methods According to the nucleotide sequence of hemolysin gene hlyA and extracellular secretion protein gene espP, specific primers were designed for PCR analysis of 113 isolates of E. coli O157. Results Isolates carrying hlyA and espP accounted for 99.1% and 72.5%, respectively. espP was only detected in E. coli O157 ∶ H7 strains harboring the large plasmid pO157. Conclusion espP was present in pO157-carring E. coli O157 ∶ H7 strains; its distribution was neither correlative with strain sources nor whether the strains carried Shiga toxin.