Enteropathogenic
Escherichia coli (EPEC) and enterohemorrhagic
Escherichia coli (EHEC) can produce attaching and effacing (AE) lesions on intestinal epithelium
in vitro and
in vivo. A gene necessary to cause the AE lesion has been identified and designated
Escherichia coli attaching and effacing A (
eaeA) gene. In this study, an alkaline phosphatase (ALP)-conjugated oligonucleotide probe for the
eaeA gene was developed and used to detect the
eaeA gene among 163 strains of classical EPEC and 25 strains of EHEC O157. The prevalence rates of
eaeA gene in the strains of classical EPEC and EHEC O157 were 51.5 and 100%, respectively. The
eaeA-positive rate (60.0%) in strains of class I EPEC serogroups (O26, O55, O86, O111, O119, O125, O126, O127, O128ab, and O142) was significantly higher than that (22.9%) in strains of the class II EPEC serogroups (O18, O44, O114)(
P<0.01). A total of 109
eaeA-positive classical EPEC and EHEC O157 were positive for fluorescent actin staining (FAS) assay, whereas 79
eaeA-negative classical EPEC were negative. Both the sensitivity and specificity of the
eaeA probe versus the FAS assay positivity were 100%. Thus, use of the ALP-conjugated oligonucleotide probe for the
eaeA gene would be specific and reliable in identifying the adherence capability of EPEC and EHEC.
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