Abstract

Shigella and diarrheagenic Escherichia coli (DEC) are the most common causes of diarrheal diseases in developing countries. A multiplex polymerase chain reaction (mPCR) was developed for identification of DEC infections caused by shiga toxin producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli(ETEC), enteroinvasive E. coli (EIEC) and Shigella in feacal samples by simultaneous and specific detection of seven virulence genes (eaeA, stx1, stx2, bfpA, LT, ST and ipaH). The detection limit of the method was 10¹ to 10³ cfu/PCR assay from pure cultures. When the multiplex PCR was tested with DNA purified from artificially spiked stool samples directly from stool or after overnight pre-enrichment in buffered peptone water, the detection limit was10⁶ cfu and 10¹ - 10⁵ cfu/gm stool, respectively. The developed mPCR is specific, sensitive, easy, rapid and of low cost method for detecting DEC in stool. 

Key words: Diarrheagenic Escherichia coli, Shigella, shiga toxin producing E. coli(STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenicE. coli (ETEC), multiplex PCR.