Escherichia coli (e.coli) is an important member of the normal intestinal microflora for mammals, including humans.diarrheagenic escherichia coli (dec) is an emerging agent among pathogen that cause diarrhea. that disease is still amajor health problem, especially in developing countries, this pathogen cause of morbidity and mortality especially in children. e.coli of many different serotypes categorized into six major groups according to virulence factor profiles, severity of clinical manifestations and prognosis. studies showed that diarrheagenice.coli (dec) such as enterohaemorrhagice.coli (ehec), enteroaggregativee.coli (eaec), enteropathogenice.coli(epec), enteroinvasivee.coli (eiec) ,enterotoxigenice.coli (etec) and shiga toxin producing e.coli (stec) strain are among the most prevalent causative agents in acute diarrhea, particulary in children.
Methods
Totaly 325 isoltes (5 colonies of each 65 samples) were collected from patients with diarrhea in tehran province of iran, during 2013. e.coli strains were isolated by traditional culture and standard biochemical identification test ,the diarrheagenic genes isolated by polymerase chain reaction (pcr) technique to detect presence of virulence genes eae, stx1 and stx2 for ehec, bfp and eae for epec, lt and st for etec, aa for eaec, inve for eiec, stx1 or stx2 for stec.
Results
A total of 65 stool samples were tested in which 50(77%) were identified e.coli by traditional cultures and biochemical identification test.
Conclusion
According to the previous studies on this subject that reported different frequency and mix data, this study is part of widespread plan that we can achieve to comprehensive and full refrence.phenotypic assey are routinely used in most laboratories characterize dec strains. in this study, six distinct pathotypes of diarrheagenic e.coli were detected in all of group age in tehran. stec mostly affected children less than 5 years old but epec and etec and eaec were seen in any age groups mostly seen in children.it seems that in tehran province with hot and wet weather, prevalence of these pathothypes are more than other regions that have colder or dryer weather. on the otherhand the prevalence of different pathotypes was variable and some pathotypes were more prevalent than others.in this study, it could be suggested to pay serological studies for the better treatment and access to vaccine.
