[The characteristic of diarrheagenic Escherichia separated from children aged under 5 years old in Yaroslavl.]

The diarrheagenic bacteria coli take a significant place among agents of acute intestinal infections in children aged under 5 years. The main danger among these pathogens is represented by both enterotoxigenic E. coli causing enteritis and enterocolitis accompanied by acute dehydration diarrhea and Escherichia producing shiga-toxin being agents of hemorrhagic colitis and hemolytic uremic syndrome. The fast and proper identification of agents of these two groups of pathogens is an important task of bacteriologists to be resolved for successful treatment of patient because tactics of therapy of enterotoxigenic diarrhea and hemorrhagic colitis and hemolytic uremic syndrome significantly differ. The high capacity of Escherichia coli to form populations resistant to anti-microbial medications, including pan-resistant ones, also is a serious problem for science and public health. The object of study was a collection of isolates of E. coli (n = 112), separated from 112 children aged under 5 years with clinical manifestations of acute intestinal infection, food toxic infection hemocolitis and diarrhea of obscure etiology in Yaroslavl in 2015-2017. Initially, the strains of E. coli were tested using diagnostic agglutinating coli-serums and then using reagents' kit «AmpliSens®Escherichiosis-FL¼ for detection and differentiation DNAof diarrheagenic bacteria coli and also with specific oligonucleotide primers to genes of virulence and O-serum group belonging. The obtained data permitted to determine belonging of analyzed strains of E. coli to four sub-groups: ЕНЕС (n = 9), EPEC (n = 17), ETEC (n = 1) и EAgEС (n = 1). All of them were agents of genes of pathogenicity specific for every pathogroup. The most numerous group EPEC was represented by strains of five serogroups with dominating among them serogroup O26 (9 strains). Therefore, studying collection of strains of diarrheagenic Escherichia isolated during 2015-1017 in Yaroslavl from children aged under 5 years with acute intestinal infections permitted to demonstrate efficiency of application of molecular genetic methods of analysis for characterizing E. coli i.e. establishment their serogroups, detection of genes of virulence and attributing to pathogroups.