Determination of adhesion virulence factors of enteropathogenic escherichia coli [eaeA,bfpA] isolates from asymptomatic individuals compared to those with diarrhea

ABSTRACT

The aim of the this study was to investigate the prevalence of toxB, paa, Ipf and iha adhesion genes in enteropathogenic Escherichia coli [EPEC] isolates lacking in two important adhesion factors, the eaeA and bfpA genes. We examined a total of 70 serologically confirmed EPEC [eaeA, bfpA] isolates. DNA from the isolates was extracted by the phenol-chloroform method. toxB, paa, Ipf and iha adhesion genes in the EPEC isolates were detected by polymerase chain reaction. Data were analyzed by SPSS software and statistical analysis using the chi square test. P-values less than 0.05 were considered significant. PCR was positive for the toxB gene in 2 [2.85%], paa in 3 [4.28%], Ipf in 32 [45.71%] and iha in 15 [21.42%] of the 70 strains. Statistically, none of the toxB.paa, and Ipf genes were associated with diarrhea. However, the iha gene showed a weak significant relation to diarrhea [P=0.11]. The main mechanism of pathogenicity for EPEC is attachment and effacement. Therefore, EPEC [eaeA, bfpA] should have another adhesin factor, which should be investigated. EPEC strains [eaeA-, bfpA-] that possess the Ipf gene are common. Further investigations of the virulence properties of these strains are necessary in order to elucidate the role of these virulence factors in diarrhea among Iranian children