The diarrhea and other symptoms of EPEC infections probably are caused by bacterial invasion of host cells and interference with normal cellular signal transduction, rather than by production of toxins.
Studies with adult volunteers have demonstratedthat intimin, pEAF and BFP are essential virulence deter-minants of EPEC [10-12]. Interestingly, there is evidencethat a subset of EPEC strains, known as atypical EPEC(aEPEC), which lack pEAF and BFP, are also pathogenic
EPEC strains may be either typical, producing bundle forming pili(encoded by the bfpA gene) that mediatelocalised adherence on cultured epithelial cells, or atypical, which are negative for these appendages but show localised like adherence,diffuse adherence or aggregative adherence patterns and produce diarrhae in developing worlds.Virulance gene is bfp for typical and non typical
IntroductionEnteric bacterial diseasesEtiologic bacteriological diagnosis by classical cultures techniques do not allow detection and identiﬁcation of the most frequent diarrheagenic Escherichia coli in our countries as enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC).
EPEC is a leading cause of diarrhea in developing countries.In industrialized countries, the frequency of these organisms has decreased, but they continue to be an important cause of diarrhea .
EPEC was ﬁrst reported by John Bray in 1945as the cause of diarrhea outbreak in London 5
Classification of Enteropathogenic E. coliPathotype Clin Features Epidem. Features Virulence factorsEPEC Watery diarr., Infants, Bundle forming pilus, vomiting Developing attaching-effacing countriesEHEC Watery diarr., Food & water Shiga toxins, attaching- Hg. colitis borne effacingETEC Watery diarr Childhood diarr., Pili, ST & LT entero Travelers diarr. toxinsEAEC Diarr with Childhood diarr. Pili, cytotoxins mucusEIEC Dysentery/ Food borne Cellular invasion, intra watery diarr cellular motility
Primer Design Primer Name5’-GGA AGT CAA ATT CAT GGG GGT AT bfp F bfp R5’-GGA ATC AGA CGC AGA CTG GTA GT
PCR and Gradient PCR Temperature Time Cycle(s)Gradient PCR 94 5 min 1 for samples g=5 94 45 sec 52 1min 40 72 1min 72 5 min 1 Primer F 1 l Primer R 1 l10mM dNTP Mix10X Taq 22 l buffer Containing 1. 5mm MgCl2 Taq Polymerase 1U DNA 1 l
Gel agarose electrophoresis 1 2 3 4 5 6 7 8 PCR Product= 250 bp 1= ladder 100bp plus fermentas 2-7 = sample 8 = negative control 250 bp
Gel Extraction This methode did by Commercial Corebio Kit