Validity of multiplex PCR as an emerging technique for diagnosis of enterotoxigenic Escherichia coli

Diarrhea continues to be one of the most common causes of morbidity and mortality among travelers and residents of developing countries especially infants and children. Enterotoxigenic E.coli is an emerging agent among pathogens that cause diarrhea. Enterotoxigenic E.coli produces either a heat-stable toxin or a heat-labile toxin, or both, encoded by plasmid-borne ST and LT genes, respectively. Diagnosis of infection with this subclass of E.coli can be performed with conventional biochemical reactions and API 20E system; however, the sensitivity and specificity of these methods are insufficient. A multiplex PCR assay that provides a sensitive and specific method for detecting the presence of either or both toxin genes has been developed. Two sets of primers were used to simultaneously detect the genes encoding LT and ST in order to detect all types of ETEC. The results for samples from patients indicated that the multiplex PCR assay had greater sensitivity and specificity than conventional biochemical reactions and API 20E system