Open AccessMolecular-genetic characteristics of strain Escherichia coli serogroup O26 causing diarrheal diseases in children
Author(s) -
М. В. Макарова,
М. В. Макарова,
А. В. Дмитриев,
А. В. Дмитриев,
З. Н. Матвеева,
З. Н. Матвеева,
K A Kaftyreva,
Л А Кафтырева
Publication year - 2018
Publication title -
medicinskij akademičeskij žurnal
Language(s) - English
Resource type - Journals
eISSN - 2687-1378
pISSN - 1608-4101
DOI - 10.17816/maj18385-90
Subject(s) - virulence , serotype , microbiology and biotechnology , biology , stx2 , escherichia coli , virology , gene , phylogenetic tree , population , shiga toxin , genetics , medicine , environmental health
Aim. To determine the serotype and virulence factors of the E. coli serogroup O26 isolated from children with diarrheal syndrome. Materials and methods. Fifty-three strains of E. coli O26 isolated in 2014-2016 from the stool of children with clinical manifestations of acute intestinal infection in Saint Petersburg were studied. Phenotypic (enzymatic and antigenic properties), molecular genetic [detection of virulence genes of enteropathogenic (EPEC - eae, bfp, hlyA), and enterohemorrhagic (EHEC - eae, stx1, stx2, ehxA), genes encoding O- and H-antigens (rfb and fliC), genes, defining phylogenetic group (chuA, yjaA и TspE)] methods were used. The phylogenetic group and the production Shiga toxins were determined. Results. All strains were identical to the antigen characteristics of serotype O26:H11 and phylogenetic group B1. Two pathogroups were created based on the set of virulence genes: a-EPEC (64.2%) and EHEC (35.8%). Strains EHEC produced Shiga-toxin 1, encoding gen stx1. No differences in enzymatic activities were found between the strains of E. coli О26:H11 for EPEC and EHEC strains. Conclusion. In the population of E. coli O26:H11, which caused acute intestinal infection in children in Saint Petersburg, more than 30% of the strains belonged to the highly virulent group EHEC. Molecular-genetic methods should be used for reliable detection of pathogens.