The detection of strains of Esherichia coli producing shiga toxin in populations of normal intestinal microbiota in children with functional disorders of gastrointestinal tract
In intestinal ecosystem, interchange of genetic material between different types of bacteria and other representatives of family Enterobacteriaceae results in development of types of normal colibacillus with genetic characteristics of pathogenicity. This occurrence can be considered as a theoretical substantiation for labeling such strains as pathobionts. The polymerase chain reaction was implemented to analyze 96 strains of different types of Escherichia coli (with normal and weak zymogenic activity and hemolytic activity) isolated from children with functional disorders of gastrointestinal tract. The purpose was to detect presence of gens coding capacity of toxin production (stx1, stx2). In intestinal biotope of children, circulation of strains of Escherichia coli producing shiga toxin having no relation to pathogenic group being representatives of normal indigenous microbiota. The presence of gens stxl and stx2 in various biochemical types of Escherichia coli permits establishing fact of forming of reservoir ofpotential pathogenicity in non-pathogenic forms of Escherichia coli. The presence of gen (verotoxin 1) in genome of various types of Escherichia coli isolated from one single biotope testifies possible horizontal transmission of factors ofpathogenicity in intestinal biotope.